Scalability and performance

OpenShift Container Platform 4.14

Scaling your OpenShift Container Platform cluster and tuning performance in production environments

Red Hat OpenShift Documentation Team

Abstract

This document provides instructions for scaling your cluster and optimizing the performance of your OpenShift Container Platform environment.

Chapter 1. OpenShift Container Platform scalability and performance overview

OpenShift Container Platform provides best practices and tools to help you optimize the performance and scale of your clusters. The following documentation provides information on recommended performance and scalability practices, reference design specifications, optimization, and low latency tuning.

To contact Red Hat support, see Getting support.

Note

Some performance and scalability Operators have release cycles that are independent from OpenShift Container Platform release cycles. For more information, see Openshift Operators.

Chapter 2. Recommended performance and scalability practices

2.1. Recommended control plane practices

This topic provides recommended performance and scalability practices for control planes in OpenShift Container Platform.

2.1.1. Recommended practices for scaling the cluster

The guidance in this section is only relevant for installations with cloud provider integration.

Apply the following best practices to scale the number of worker machines in your OpenShift Container Platform cluster. You scale the worker machines by increasing or decreasing the number of replicas that are defined in the worker machine set.

When scaling up the cluster to higher node counts:

Spread nodes across all of the available zones for higher availability.
Scale up by no more than 25 to 50 machines at once.
Consider creating new compute machine sets in each available zone with alternative instance types of similar size to help mitigate any periodic provider capacity constraints. For example, on AWS, use m5.large and m5d.large.

Note

Cloud providers might implement a quota for API services. Therefore, gradually scale the cluster.

The controller might not be able to create the machines if the replicas in the compute machine sets are set to higher numbers all at one time. The number of requests the cloud platform, which OpenShift Container Platform is deployed on top of, is able to handle impacts the process. The controller will start to query more while trying to create, check, and update the machines with the status. The cloud platform on which OpenShift Container Platform is deployed has API request limits; excessive queries might lead to machine creation failures due to cloud platform limitations.

Enable machine health checks when scaling to large node counts. In case of failures, the health checks monitor the condition and automatically repair unhealthy machines.

Note

When scaling large and dense clusters to lower node counts, it might take large amounts of time because the process involves draining or evicting the objects running on the nodes being terminated in parallel. Also, the client might start to throttle the requests if there are too many objects to evict. The default client queries per second (QPS) and burst rates are currently set to 50 and 100 respectively. These values cannot be modified in OpenShift Container Platform.

2.1.2. Control plane node sizing

The control plane node resource requirements depend on the number and type of nodes and objects in the cluster. The following control plane node size recommendations are based on the results of a control plane density focused testing, or Cluster-density. This test creates the following objects across a given number of namespaces:

1 image stream
1 build
5 deployments, with 2 pod replicas in a sleep state, mounting 4 secrets, 4 config maps, and 1 downward API volume each
5 services, each one pointing to the TCP/8080 and TCP/8443 ports of one of the previous deployments
1 route pointing to the first of the previous services
10 secrets containing 2048 random string characters
10 config maps containing 2048 random string characters

Number of worker nodes	Cluster-density (namespaces)	CPU cores	Memory (GB)
24	500	4	16
120	1000	8	32
252	4000	16, but 24 if using the OVN-Kubernetes network plug-in	64, but 128 if using the OVN-Kubernetes network plug-in
501, but untested with the OVN-Kubernetes network plug-in	4000	16	96

The data from the table above is based on an OpenShift Container Platform running on top of AWS, using r5.4xlarge instances as control-plane nodes and m5.2xlarge instances as worker nodes.

On a large and dense cluster with three control plane nodes, the CPU and memory usage will spike up when one of the nodes is stopped, rebooted, or fails. The failures can be due to unexpected issues with power, network, underlying infrastructure, or intentional cases where the cluster is restarted after shutting it down to save costs. The remaining two control plane nodes must handle the load in order to be highly available, which leads to increase in the resource usage. This is also expected during upgrades because the control plane nodes are cordoned, drained, and rebooted serially to apply the operating system updates, as well as the control plane Operators update. To avoid cascading failures, keep the overall CPU and memory resource usage on the control plane nodes to at most 60% of all available capacity to handle the resource usage spikes. Increase the CPU and memory on the control plane nodes accordingly to avoid potential downtime due to lack of resources.

Important

The node sizing varies depending on the number of nodes and object counts in the cluster. It also depends on whether the objects are actively being created on the cluster. During object creation, the control plane is more active in terms of resource usage compared to when the objects are in the running phase.

Operator Lifecycle Manager (OLM ) runs on the control plane nodes and its memory footprint depends on the number of namespaces and user installed operators that OLM needs to manage on the cluster. Control plane nodes need to be sized accordingly to avoid OOM kills. Following data points are based on the results from cluster maximums testing.

Number of namespaces	OLM memory at idle state (GB)	OLM memory with 5 user operators installed (GB)
500	0.823	1.7
1000	1.2	2.5
1500	1.7	3.2
2000	2	4.4
3000	2.7	5.6
4000	3.8	7.6
5000	4.2	9.02
6000	5.8	11.3
7000	6.6	12.9
8000	6.9	14.8
9000	8	17.7
10,000	9.9	21.6

Important

You can modify the control plane node size in a running OpenShift Container Platform 4.14 cluster for the following configurations only:

Clusters installed with a user-provisioned installation method.
AWS clusters installed with an installer-provisioned infrastructure installation method.
Clusters that use a control plane machine set to manage control plane machines.

For all other configurations, you must estimate your total node count and use the suggested control plane node size during installation.

Important

The recommendations are based on the data points captured on OpenShift Container Platform clusters with OpenShift SDN as the network plugin.

Note

In OpenShift Container Platform 4.14, half of a CPU core (500 millicore) is now reserved by the system by default compared to OpenShift Container Platform 3.11 and previous versions. The sizes are determined taking that into consideration.

2.1.2.1. Selecting a larger Amazon Web Services instance type for control plane machines

If the control plane machines in an Amazon Web Services (AWS) cluster require more resources, you can select a larger AWS instance type for the control plane machines to use.

Note

The procedure for clusters that use a control plane machine set is different from the procedure for clusters that do not use a control plane machine set.

If you are uncertain about the state of the ControlPlaneMachineSet CR in your cluster, you can verify the CR status.

2.1.2.1.1. Changing the Amazon Web Services instance type by using a control plane machine set

You can change the Amazon Web Services (AWS) instance type that your control plane machines use by updating the specification in the control plane machine set custom resource (CR).

Prerequisites

Your AWS cluster uses a control plane machine set.

Procedure

Edit your control plane machine set CR by running the following command:

$ oc --namespace openshift-machine-api edit controlplanemachineset.machine.openshift.io cluster

Edit the following line under the providerSpec field:
```
providerSpec:
  value:
    ...
    instanceType: <compatible_aws_instance_type> 1
```
1
Specify a larger AWS instance type with the same base as the previous selection. For example, you can change m6i.xlarge to m6i.2xlarge or m6i.4xlarge.
Save your changes.
- For clusters that use the default RollingUpdate update strategy, the Operator automatically propagates the changes to your control plane configuration.
- For clusters that are configured to use the OnDelete update strategy, you must replace your control plane machines manually.

Additional resources

Managing control plane machines with control plane machine sets

2.1.2.1.2. Changing the Amazon Web Services instance type by using the AWS console

You can change the Amazon Web Services (AWS) instance type that your control plane machines use by updating the instance type in the AWS console.

Prerequisites

You have access to the AWS console with the permissions required to modify the EC2 Instance for your cluster.
You have access to the OpenShift Container Platform cluster as a user with the cluster-admin role.

Procedure

Open the AWS console and fetch the instances for the control plane machines.
Choose one control plane machine instance.
1. For the selected control plane machine, back up the etcd data by creating an etcd snapshot. For more information, see "Backing up etcd".
2. In the AWS console, stop the control plane machine instance.
3. Select the stopped instance, and click Actions → Instance Settings → Change instance type.
4. Change the instance to a larger type, ensuring that the type is the same base as the previous selection, and apply changes. For example, you can change m6i.xlarge to m6i.2xlarge or m6i.4xlarge.
5. Start the instance.
6. If your OpenShift Container Platform cluster has a corresponding Machine object for the instance, update the instance type of the object to match the instance type set in the AWS console.
Repeat this process for each control plane machine.

Additional resources

2.2. Recommended infrastructure practices

This topic provides recommended performance and scalability practices for infrastructure in OpenShift Container Platform.

2.2.1. Infrastructure node sizing

Infrastructure nodes are nodes that are labeled to run pieces of the OpenShift Container Platform environment. The infrastructure node resource requirements depend on the cluster age, nodes, and objects in the cluster, as these factors can lead to an increase in the number of metrics or time series in Prometheus. The following infrastructure node size recommendations are based on the results observed in cluster-density testing detailed in the Control plane node sizing section, where the monitoring stack and the default ingress-controller were moved to these nodes.

Number of worker nodes	Cluster density, or number of namespaces	CPU cores	Memory (GB)
27	500	4	24
120	1000	8	48
252	4000	16	128
501	4000	32	128

In general, three infrastructure nodes are recommended per cluster.

Important

These sizing recommendations should be used as a guideline. Prometheus is a highly memory intensive application; the resource usage depends on various factors including the number of nodes, objects, the Prometheus metrics scraping interval, metrics or time series, and the age of the cluster. In addition, the router resource usage can also be affected by the number of routes and the amount/type of inbound requests.

These recommendations apply only to infrastructure nodes hosting Monitoring, Ingress and Registry infrastructure components installed during cluster creation.

Note

2.2.2. Scaling the Cluster Monitoring Operator

OpenShift Container Platform exposes metrics that the Cluster Monitoring Operator (CMO) collects and stores in the Prometheus-based monitoring stack. As an administrator, you can view dashboards for system resources, containers, and components metrics in the OpenShift Container Platform web console by navigating to Observe → Dashboards.

2.2.3. Prometheus database storage requirements

Red Hat performed various tests for different scale sizes.

Note

The following Prometheus storage requirements are not prescriptive and should be used as a reference. Higher resource consumption might be observed in your cluster depending on workload activity and resource density, including the number of pods, containers, routes, or other resources exposing metrics collected by Prometheus.
You can configure the size-based data retention policy to suit your storage requirements.

Table 2.1. Prometheus Database storage requirements based on number of nodes/pods in the cluster
Number of nodes	Number of pods (2 containers per pod)	Prometheus storage growth per day	Prometheus storage growth per 15 days	Network (per tsdb chunk)
50	1800	6.3 GB	94 GB	16 MB
100	3600	13 GB	195 GB	26 MB
150	5400	19 GB	283 GB	36 MB
200	7200	25 GB	375 GB	46 MB

Approximately 20 percent of the expected size was added as overhead to ensure that the storage requirements do not exceed the calculated value.

The above calculation is for the default OpenShift Container Platform Cluster Monitoring Operator.

Note

CPU utilization has minor impact. The ratio is approximately 1 core out of 40 per 50 nodes and 1800 pods.

Recommendations for OpenShift Container Platform

Use at least two infrastructure (infra) nodes.
Use at least three openshift-container-storage nodes with non-volatile memory express (SSD or NVMe) drives.

2.2.4. Configuring cluster monitoring

You can increase the storage capacity for the Prometheus component in the cluster monitoring stack.

Procedure

To increase the storage capacity for Prometheus:

Create a YAML configuration file, cluster-monitoring-config.yaml. For example:

apiVersion: v1
kind: ConfigMap
data:
  config.yaml: |
    prometheusK8s:
      retention: {{PROMETHEUS_RETENTION_PERIOD}} 1
      nodeSelector:
        node-role.kubernetes.io/infra: ""
      volumeClaimTemplate:
        spec:
          storageClassName: {{STORAGE_CLASS}} 2
          resources:
            requests:
              storage: {{PROMETHEUS_STORAGE_SIZE}} 3
    alertmanagerMain:
      nodeSelector:
        node-role.kubernetes.io/infra: ""
      volumeClaimTemplate:
        spec:
          storageClassName: {{STORAGE_CLASS}} 4
          resources:
            requests:
              storage: {{ALERTMANAGER_STORAGE_SIZE}} 5
metadata:
  name: cluster-monitoring-config
  namespace: openshift-monitoring

1: The default value of Prometheus retention is PROMETHEUS_RETENTION_PERIOD=15d. Units are measured in time using one of these suffixes: s, m, h, d.
2 4: The storage class for your cluster.
3: A typical value is PROMETHEUS_STORAGE_SIZE=2000Gi. Storage values can be a plain integer or a fixed-point integer using one of these suffixes: E, P, T, G, M, K. You can also use the power-of-two equivalents: Ei, Pi, Ti, Gi, Mi, Ki.
5: A typical value is ALERTMANAGER_STORAGE_SIZE=20Gi. Storage values can be a plain integer or a fixed-point integer using one of these suffixes: E, P, T, G, M, K. You can also use the power-of-two equivalents: Ei, Pi, Ti, Gi, Mi, Ki.

Add values for the retention period, storage class, and storage sizes.
Save the file.

Apply the changes by running:

$ oc create -f cluster-monitoring-config.yaml

2.2.5. Additional resources

2.3. Recommended etcd practices

This topic provides recommended performance and scalability practices for etcd in OpenShift Container Platform.

2.3.1. Recommended etcd practices

Because etcd writes data to disk and persists proposals on disk, its performance depends on disk performance. Although etcd is not particularly I/O intensive, it requires a low latency block device for optimal performance and stability. Because etcd’s consensus protocol depends on persistently storing metadata to a log (WAL), etcd is sensitive to disk-write latency. Slow disks and disk activity from other processes can cause long fsync latencies.

Those latencies can cause etcd to miss heartbeats, not commit new proposals to the disk on time, and ultimately experience request timeouts and temporary leader loss. High write latencies also lead to an OpenShift API slowness, which affects cluster performance. Because of these reasons, avoid colocating other workloads on the control-plane nodes that are I/O sensitive or intensive and share the same underlying I/O infrastructure.

In terms of latency, run etcd on top of a block device that can write at least 50 IOPS of 8000 bytes long sequentially. That is, with a latency of 10ms, keep in mind that uses fdatasync to synchronize each write in the WAL. For heavy loaded clusters, sequential 500 IOPS of 8000 bytes (2 ms) are recommended. To measure those numbers, you can use a benchmarking tool, such as fio.

To achieve such performance, run etcd on machines that are backed by SSD or NVMe disks with low latency and high throughput. Consider single-level cell (SLC) solid-state drives (SSDs), which provide 1 bit per memory cell, are durable and reliable, and are ideal for write-intensive workloads.

Note

The load on etcd arises from static factors, such as the number of nodes and pods, and dynamic factors, including changes in endpoints due to pod autoscaling, pod restarts, job executions, and other workload-related events. To accurately size your etcd setup, you must analyze the specific requirements of your workload. Consider the number of nodes, pods, and other relevant factors that impact the load on etcd.

The following hard drive practices provide optimal etcd performance:

Use dedicated etcd drives. Avoid drives that communicate over the network, such as iSCSI. Do not place log files or other heavy workloads on etcd drives.
Prefer drives with low latency to support fast read and write operations.
Prefer high-bandwidth writes for faster compactions and defragmentation.
Prefer high-bandwidth reads for faster recovery from failures.
Use solid state drives as a minimum selection. Prefer NVMe drives for production environments.
Use server-grade hardware for increased reliability.

Note

Avoid NAS or SAN setups and spinning drives. Ceph Rados Block Device (RBD) and other types of network-attached storage can result in unpredictable network latency. To provide fast storage to etcd nodes at scale, use PCI passthrough to pass NVM devices directly to the nodes.

Always benchmark by using utilities such as fio. You can use such utilities to continuously monitor the cluster performance as it increases.

Note

Avoid using the Network File System (NFS) protocol or other network based file systems.

Some key metrics to monitor on a deployed OpenShift Container Platform cluster are p99 of etcd disk write ahead log duration and the number of etcd leader changes. Use Prometheus to track these metrics.

Note

The etcd member database sizes can vary in a cluster during normal operations. This difference does not affect cluster upgrades, even if the leader size is different from the other members.

To validate the hardware for etcd before or after you create the OpenShift Container Platform cluster, you can use fio.

Prerequisites

Container runtimes such as Podman or Docker are installed on the machine that you’re testing.
Data is written to the /var/lib/etcd path.

Procedure

Run fio and analyze the results:

If you use Podman, run this command:

$ sudo podman run --volume /var/lib/etcd:/var/lib/etcd:Z quay.io/cloud-bulldozer/etcd-perf

If you use Docker, run this command:

$ sudo docker run --volume /var/lib/etcd:/var/lib/etcd:Z quay.io/cloud-bulldozer/etcd-perf

The output reports whether the disk is fast enough to host etcd by comparing the 99th percentile of the fsync metric captured from the run to see if it is less than 10 ms. A few of the most important etcd metrics that might affected by I/O performance are as follow:

etcd_disk_wal_fsync_duration_seconds_bucket metric reports the etcd’s WAL fsync duration
etcd_disk_backend_commit_duration_seconds_bucket metric reports the etcd backend commit latency duration
etcd_server_leader_changes_seen_total metric reports the leader changes

Because etcd replicates the requests among all the members, its performance strongly depends on network input/output (I/O) latency. High network latencies result in etcd heartbeats taking longer than the election timeout, which results in leader elections that are disruptive to the cluster. A key metric to monitor on a deployed OpenShift Container Platform cluster is the 99th percentile of etcd network peer latency on each etcd cluster member. Use Prometheus to track the metric.

The histogram_quantile(0.99, rate(etcd_network_peer_round_trip_time_seconds_bucket[2m])) metric reports the round trip time for etcd to finish replicating the client requests between the members. Ensure that it is less than 50 ms.

Additional resources

2.3.2. Moving etcd to a different disk

You can move etcd from a shared disk to a separate disk to prevent or resolve performance issues.

The Machine Config Operator (MCO) is responsible for mounting a secondary disk for OpenShift Container Platform 4.14 container storage.

Note

This encoded script only supports device names for the following device types:

SCSI or SATA: /dev/sd*
Virtual device: /dev/vd*
NVMe: /dev/nvme*[0-9]*n*

Limitations

When the new disk is attached to the cluster, the etcd database is part of the root mount. It is not part of the secondary disk or the intended disk when the primary node is recreated. As a result, the primary node will not create a separate /var/lib/etcd mount.

Prerequisites

You have a backup of your cluster’s etcd data.
You have installed the OpenShift CLI (oc).
You have access to the cluster with cluster-admin privileges.
Add additional disks before uploading the machine configuration.
The MachineConfigPool must match metadata.labels[machineconfiguration.openshift.io/role]. This applies to a controller, worker, or a custom pool.

Note

This procedure does not move parts of the root file system, such as /var/, to another disk or partition on an installed node.

Important

This procedure is not supported when using control plane machine sets.

Procedure

Attach the new disk to the cluster and verify that the disk is detected in the node by running the lsblk command in a debug shell:
```
$ oc debug node/<node_name>
```
```
# lsblk
```
Note the device name of the new disk reported by the lsblk command.

Create the following script and name it etcd-find-secondary-device.sh:

#!/bin/bash
set -uo pipefail

for device in <device_type_glob>; do 1
/usr/sbin/blkid "${device}" &> /dev/null
 if [ $? == 2  ]; then
    echo "secondary device found ${device}"
    echo "creating filesystem for etcd mount"
    mkfs.xfs -L var-lib-etcd -f "${device}" &> /dev/null
    udevadm settle
    touch /etc/var-lib-etcd-mount
    exit
 fi
done
echo "Couldn't find secondary block device!" >&2
exit 77

1: Replace <device_type_glob> with a shell glob for your block device type. For SCSI or SATA drives, use /dev/sd*; for virtual drives, use /dev/vd*; for NVMe drives, use /dev/nvme*[0-9]*n*.

Create a base64-encoded string from the etcd-find-secondary-device.sh script and note its contents:
```
$ base64 -w0 etcd-find-secondary-device.sh
```

Create a MachineConfig YAML file named etcd-mc.yml with contents such as the following:

apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: master
  name: 98-var-lib-etcd
spec:
  config:
    ignition:
      version: 3.1.0
    storage:
      files:
        - path: /etc/find-secondary-device
          mode: 0755
          contents:
            source: data:text/plain;charset=utf-8;base64,<encoded_etcd_find_secondary_device_script> 1
    systemd:
      units:
        - name: find-secondary-device.service
          enabled: true
          contents: |
            [Unit]
            Description=Find secondary device
            DefaultDependencies=false
            After=systemd-udev-settle.service
            Before=local-fs-pre.target
            ConditionPathExists=!/etc/var-lib-etcd-mount

            [Service]
            RemainAfterExit=yes
            ExecStart=/etc/find-secondary-device

            RestartForceExitStatus=77

            [Install]
            WantedBy=multi-user.target
        - name: var-lib-etcd.mount
          enabled: true
          contents: |
            [Unit]
            Before=local-fs.target

            [Mount]
            What=/dev/disk/by-label/var-lib-etcd
            Where=/var/lib/etcd
            Type=xfs
            TimeoutSec=120s

            [Install]
            RequiredBy=local-fs.target
        - name: sync-var-lib-etcd-to-etcd.service
          enabled: true
          contents: |
            [Unit]
            Description=Sync etcd data if new mount is empty
            DefaultDependencies=no
            After=var-lib-etcd.mount var.mount
            Before=crio.service

            [Service]
            Type=oneshot
            RemainAfterExit=yes
            ExecCondition=/usr/bin/test ! -d /var/lib/etcd/member
            ExecStart=/usr/sbin/setsebool -P rsync_full_access 1
            ExecStart=/bin/rsync -ar /sysroot/ostree/deploy/rhcos/var/lib/etcd/ /var/lib/etcd/
            ExecStart=/usr/sbin/semanage fcontext -a -t container_var_lib_t '/var/lib/etcd(/.*)?'
            ExecStart=/usr/sbin/setsebool -P rsync_full_access 0
            TimeoutSec=0

            [Install]
            WantedBy=multi-user.target graphical.target
        - name: restorecon-var-lib-etcd.service
          enabled: true
          contents: |
            [Unit]
            Description=Restore recursive SELinux security contexts
            DefaultDependencies=no
            After=var-lib-etcd.mount
            Before=crio.service

            [Service]
            Type=oneshot
            RemainAfterExit=yes
            ExecStart=/sbin/restorecon -R /var/lib/etcd/
            TimeoutSec=0

            [Install]
            WantedBy=multi-user.target graphical.target

1: Replace <encoded_etcd_find_secondary_device_script> with the encoded script contents that you noted.

Verification steps

Run the grep /var/lib/etcd /proc/mounts command in a debug shell for the node to ensure that the disk is mounted:

$ oc debug node/<node_name>

# grep -w "/var/lib/etcd" /proc/mounts

Example output

/dev/sdb /var/lib/etcd xfs rw,seclabel,relatime,attr2,inode64,logbufs=8,logbsize=32k,noquota 0 0

Additional resources

Red Hat Enterprise Linux CoreOS (RHCOS)

2.3.3. Defragmenting etcd data

For large and dense clusters, etcd can suffer from poor performance if the keyspace grows too large and exceeds the space quota. Periodically maintain and defragment etcd to free up space in the data store. Monitor Prometheus for etcd metrics and defragment it when required; otherwise, etcd can raise a cluster-wide alarm that puts the cluster into a maintenance mode that accepts only key reads and deletes.

Monitor these key metrics:

etcd_server_quota_backend_bytes, which is the current quota limit
etcd_mvcc_db_total_size_in_use_in_bytes, which indicates the actual database usage after a history compaction
etcd_mvcc_db_total_size_in_bytes, which shows the database size, including free space waiting for defragmentation

Defragment etcd data to reclaim disk space after events that cause disk fragmentation, such as etcd history compaction.

History compaction is performed automatically every five minutes and leaves gaps in the back-end database. This fragmented space is available for use by etcd, but is not available to the host file system. You must defragment etcd to make this space available to the host file system.

Defragmentation occurs automatically, but you can also trigger it manually.

Note

Automatic defragmentation is good for most cases, because the etcd operator uses cluster information to determine the most efficient operation for the user.

2.3.3.1. Automatic defragmentation

The etcd Operator automatically defragments disks. No manual intervention is needed.

Verify that the defragmentation process is successful by viewing one of these logs:

etcd logs
cluster-etcd-operator pod
operator status error log

Warning

Automatic defragmentation can cause leader election failure in various OpenShift core components, such as the Kubernetes controller manager, which triggers a restart of the failing component. The restart is harmless and either triggers failover to the next running instance or the component resumes work again after the restart.

Example log output for successful defragmentation

etcd member has been defragmented: <member_name>, memberID: <member_id>

Example log output for unsuccessful defragmentation

failed defrag on member: <member_name>, memberID: <member_id>: <error_message>

2.3.3.2. Manual defragmentation

A Prometheus alert indicates when you need to use manual defragmentation. The alert is displayed in two cases:

When etcd uses more than 50% of its available space for more than 10 minutes
When etcd is actively using less than 50% of its total database size for more than 10 minutes

You can also determine whether defragmentation is needed by checking the etcd database size in MB that will be freed by defragmentation with the PromQL expression: (etcd_mvcc_db_total_size_in_bytes - etcd_mvcc_db_total_size_in_use_in_bytes)/1024/1024

Warning

Defragmenting etcd is a blocking action. The etcd member will not respond until defragmentation is complete. For this reason, wait at least one minute between defragmentation actions on each of the pods to allow the cluster to recover.

Follow this procedure to defragment etcd data on each etcd member.

Prerequisites

You have access to the cluster as a user with the cluster-admin role.

Procedure

Determine which etcd member is the leader, because the leader should be defragmented last.

Get the list of etcd pods:

$ oc -n openshift-etcd get pods -l k8s-app=etcd -o wide

Example output

etcd-ip-10-0-159-225.example.redhat.com                3/3     Running     0          175m   10.0.159.225   ip-10-0-159-225.example.redhat.com   <none>           <none>
etcd-ip-10-0-191-37.example.redhat.com                 3/3     Running     0          173m   10.0.191.37    ip-10-0-191-37.example.redhat.com    <none>           <none>
etcd-ip-10-0-199-170.example.redhat.com                3/3     Running     0          176m   10.0.199.170   ip-10-0-199-170.example.redhat.com   <none>           <none>

Choose a pod and run the following command to determine which etcd member is the leader:

$ oc rsh -n openshift-etcd etcd-ip-10-0-159-225.example.redhat.com etcdctl endpoint status --cluster -w table

Example output

Defaulting container name to etcdctl.
Use 'oc describe pod/etcd-ip-10-0-159-225.example.redhat.com -n openshift-etcd' to see all of the containers in this pod.
+---------------------------+------------------+---------+---------+-----------+------------+-----------+------------+--------------------+--------+
|         ENDPOINT          |        ID        | VERSION | DB SIZE | IS LEADER | IS LEARNER | RAFT TERM | RAFT INDEX | RAFT APPLIED INDEX | ERRORS |
+---------------------------+------------------+---------+---------+-----------+------------+-----------+------------+--------------------+--------+
|  https://10.0.191.37:2379 | 251cd44483d811c3 |   3.5.9 |  104 MB |     false |      false |         7 |      91624 |              91624 |        |
| https://10.0.159.225:2379 | 264c7c58ecbdabee |   3.5.9 |  104 MB |     false |      false |         7 |      91624 |              91624 |        |
| https://10.0.199.170:2379 | 9ac311f93915cc79 |   3.5.9 |  104 MB |      true |      false |         7 |      91624 |              91624 |        |
+---------------------------+------------------+---------+---------+-----------+------------+-----------+------------+--------------------+--------+

Based on the IS LEADER column of this output, the https://10.0.199.170:2379 endpoint is the leader. Matching this endpoint with the output of the previous step, the pod name of the leader is etcd-ip-10-0-199-170.example.redhat.com.

Defragment an etcd member.

Connect to the running etcd container, passing in the name of a pod that is not the leader:
```
$ oc rsh -n openshift-etcd etcd-ip-10-0-159-225.example.redhat.com
```
Unset the ETCDCTL_ENDPOINTS environment variable:
```
sh-4.4# unset ETCDCTL_ENDPOINTS
```

Defragment the etcd member:

sh-4.4# etcdctl --command-timeout=30s --endpoints=https://localhost:2379 defrag

Example output

Finished defragmenting etcd member[https://localhost:2379]

If a timeout error occurs, increase the value for --command-timeout until the command succeeds.

Verify that the database size was reduced:

sh-4.4# etcdctl endpoint status -w table --cluster

Example output

+---------------------------+------------------+---------+---------+-----------+------------+-----------+------------+--------------------+--------+
|         ENDPOINT          |        ID        | VERSION | DB SIZE | IS LEADER | IS LEARNER | RAFT TERM | RAFT INDEX | RAFT APPLIED INDEX | ERRORS |
+---------------------------+------------------+---------+---------+-----------+------------+-----------+------------+--------------------+--------+
|  https://10.0.191.37:2379 | 251cd44483d811c3 |   3.5.9 |  104 MB |     false |      false |         7 |      91624 |              91624 |        |
| https://10.0.159.225:2379 | 264c7c58ecbdabee |   3.5.9 |   41 MB |     false |      false |         7 |      91624 |              91624 |        | 1
| https://10.0.199.170:2379 | 9ac311f93915cc79 |   3.5.9 |  104 MB |      true |      false |         7 |      91624 |              91624 |        |
+---------------------------+------------------+---------+---------+-----------+------------+-----------+------------+--------------------+--------+

This example shows that the database size for this etcd member is now 41 MB as opposed to the starting size of 104 MB.

Repeat these steps to connect to each of the other etcd members and defragment them. Always defragment the leader last.
Wait at least one minute between defragmentation actions to allow the etcd pod to recover. Until the etcd pod recovers, the etcd member will not respond.

If any NOSPACE alarms were triggered due to the space quota being exceeded, clear them.
1. Check if there are any NOSPACE alarms:
```
sh-4.4# etcdctl alarm list
```
  Example output
```
memberID:12345678912345678912 alarm:NOSPACE
```
2. Clear the alarms:
```
sh-4.4# etcdctl alarm disarm
```

2.3.4. Setting tuning parameters for etcd

You can set the control plane hardware speed to "Standard", "Slower", or the default, which is "".

The default setting allows the system to decide which speed to use. This value enables upgrades from versions where this feature does not exist, as the system can select values from previous versions.

By selecting one of the other values, you are overriding the default. If you see many leader elections due to timeouts or missed heartbeats and your system is set to "" or "Standard", set the hardware speed to "Slower" to make the system more tolerant to the increased latency.

Important

Tuning etcd latency tolerances is a Technology Preview feature only. Technology Preview features are not supported with Red Hat production service level agreements (SLAs) and might not be functionally complete. Red Hat does not recommend using them in production. These features provide early access to upcoming product features, enabling customers to test functionality and provide feedback during the development process.

For more information about the support scope of Red Hat Technology Preview features, see Technology Preview Features Support Scope.

2.3.4.1. Changing hardware speed tolerance

To change the hardware speed tolerance for etcd, complete the following steps.

Prerequisites

You have edited the cluster instance to enable TechPreviewNoUpgrade features. For more information, see "Understanding feature gates" in the Additional resources.

Procedure

Check to see what the current value is by entering the following command:
```
$ oc describe etcd/cluster | grep "Control Plane Hardware Speed"
```
Example output
```
Control Plane Hardware Speed:  <VALUE>
```
Note
If the output is empty, the field has not been set and should be considered as the default ("").

Change the value by entering the following command. Replace <value> with one of the valid values: "", "Standard", or "Slower":

$ oc patch etcd/cluster --type=merge -p '{"spec": {"controlPlaneHardwareSpeed": "<value>"}}'

The following table indicates the heartbeat interval and leader election timeout for each profile. These values are subject to change.

Profile	ETCD_HEARTBEAT_INTERVAL	ETCD_LEADER_ELECTION_TIMEOUT
`""`	Varies depending on platform	Varies depending on platform
`Standard`	100	1000
`Slower`	500	2500

Review the output:
Example output
```
etcd.operator.openshift.io/cluster patched
```
If you enter any value besides the valid values, error output is displayed. For example, if you entered "Faster" as the value, the output is as follows:
Example output
```
The Etcd "cluster" is invalid: spec.controlPlaneHardwareSpeed: Unsupported value: "Faster": supported values: "", "Standard", "Slower"
```

Verify that the value was changed by entering the following command:

$ oc describe etcd/cluster | grep "Control Plane Hardware Speed"

Example output

Control Plane Hardware Speed:  ""

Wait for etcd pods to roll out:

$ oc get pods -n openshift-etcd -w

The following output shows the expected entries for master-0. Before you continue, wait until all masters show a status of 4/4 Running.

Example output

installer-9-ci-ln-qkgs94t-72292-9clnd-master-0           0/1     Pending             0          0s
installer-9-ci-ln-qkgs94t-72292-9clnd-master-0           0/1     Pending             0          0s
installer-9-ci-ln-qkgs94t-72292-9clnd-master-0           0/1     ContainerCreating   0          0s
installer-9-ci-ln-qkgs94t-72292-9clnd-master-0           0/1     ContainerCreating   0          1s
installer-9-ci-ln-qkgs94t-72292-9clnd-master-0           1/1     Running             0          2s
installer-9-ci-ln-qkgs94t-72292-9clnd-master-0           0/1     Completed           0          34s
installer-9-ci-ln-qkgs94t-72292-9clnd-master-0           0/1     Completed           0          36s
installer-9-ci-ln-qkgs94t-72292-9clnd-master-0           0/1     Completed           0          36s
etcd-guard-ci-ln-qkgs94t-72292-9clnd-master-0            0/1     Running             0          26m
etcd-ci-ln-qkgs94t-72292-9clnd-master-0                  4/4     Terminating         0          11m
etcd-ci-ln-qkgs94t-72292-9clnd-master-0                  4/4     Terminating         0          11m
etcd-ci-ln-qkgs94t-72292-9clnd-master-0                  0/4     Pending             0          0s
etcd-ci-ln-qkgs94t-72292-9clnd-master-0                  0/4     Init:1/3            0          1s
etcd-ci-ln-qkgs94t-72292-9clnd-master-0                  0/4     Init:2/3            0          2s
etcd-ci-ln-qkgs94t-72292-9clnd-master-0                  0/4     PodInitializing     0          3s
etcd-ci-ln-qkgs94t-72292-9clnd-master-0                  3/4     Running             0          4s
etcd-guard-ci-ln-qkgs94t-72292-9clnd-master-0            1/1     Running             0          26m
etcd-ci-ln-qkgs94t-72292-9clnd-master-0                  3/4     Running             0          20s
etcd-ci-ln-qkgs94t-72292-9clnd-master-0                  4/4     Running             0          20s

Enter the following command to review to the values:
```
$ oc describe -n openshift-etcd pod/<ETCD_PODNAME> | grep -e HEARTBEAT_INTERVAL -e ELECTION_TIMEOUT
```
Note
These values might not have changed from the default.

Additional resources

Understanding feature gates

Chapter 3. Reference design specifications

3.1. Telco core and RAN DU reference design specifications

The telco core reference design specification (RDS) describes OpenShift Container Platform 4.14 clusters running on commodity hardware that can support large scale telco applications including control plane and some centralized data plane functions.

The telco RAN RDS describes the configuration for clusters running on commodity hardware to host 5G workloads in the Radio Access Network (RAN).

3.1.1. Reference design specifications for telco 5G deployments

Red Hat and certified partners offer deep technical expertise and support for networking and operational capabilities required to run telco applications on OpenShift Container Platform 4.14 clusters.

Red Hat’s telco partners require a well-integrated, well-tested, and stable environment that can be replicated at scale for enterprise 5G solutions. The telco core and RAN DU reference design specifications (RDS) outline the recommended solution architecture based on a specific version of OpenShift Container Platform. Each RDS describes a tested and validated platform configuration for telco core and RAN DU use models. The RDS ensures an optimal experience when running your applications by defining the set of critical KPIs for telco 5G core and RAN DU. Following the RDS minimizes high severity escalations and improves application stability.

5G use cases are evolving and your workloads are continually changing. Red Hat is committed to iterating over the telco core and RAN DU RDS to support evolving requirements based on customer and partner feedback.

3.1.2. Reference design scope

The telco core and telco RAN reference design specifications (RDS) capture the recommended, tested, and supported configurations to get reliable and repeatable performance for clusters running the telco core and telco RAN profiles.

Each RDS includes the released features and supported configurations that are engineered and validated for clusters to run the individual profiles. The configurations provide a baseline OpenShift Container Platform installation that meets feature and KPI targets. Each RDS also describes expected variations for each individual configuration. Validation of each RDS includes many long duration and at-scale tests.

Note

The validated reference configurations are updated for each major Y-stream release of OpenShift Container Platform. Z-stream patch releases are periodically re-tested against the reference configurations.

3.1.3. Deviations from the reference design

Deviating from the validated telco core and telco RAN DU reference design specifications (RDS) can have significant impact beyond the specific component or feature that you change. Deviations require analysis and engineering in the context of the complete solution.

Important

All deviations from the RDS should be analyzed and documented with clear action tracking information. Due diligence is expected from partners to understand how to bring deviations into line with the reference design. This might require partners to provide additional resources to engage with Red Hat to work towards enabling their use case to achieve a best in class outcome with the platform. This is critical for the supportability of the solution and ensuring alignment across Red Hat and with partners.

Deviation from the RDS can have some or all of the following consequences:

It can take longer to resolve issues.
There is a risk of missing project service-level agreements (SLAs), project deadlines, end provider performance requirements, and so on.
Unapproved deviations may require escalation at executive levels.
Note
Red Hat prioritizes the servicing of requests for deviations based on partner engagement priorities.

3.2. Telco RAN DU reference design specification

3.2.1. Telco RAN DU 4.14 reference design overview

The Telco RAN distributed unit (DU) 4.14 reference design configures an OpenShift Container Platform 4.14 cluster running on commodity hardware to host telco RAN DU workloads. It captures the recommended, tested, and supported configurations to get reliable and repeatable performance for a cluster running the telco RAN DU profile.

3.2.1.1. OpenShift Container Platform 4.14 features for telco RAN DU

The following features that are included in OpenShift Container Platform 4.14 and are leveraged by the telco RAN DU reference design specification (RDS) have been added or updated.

Table 3.1. OpenShift Container Platform 4.14 features for the telco RAN DU RDS
Feature	Description
GitOps ZTP independence from managed cluster version	You can now use GitOps ZTP to manage clusters that are running different versions of OpenShift Container Platform compared to the version that is running on the hub cluster. You can also have a mix of OpenShift Container Platform versions in the deployed fleet of clusters. Preparing the GitOps ZTP site configuration repository for version independence
Using custom CRs alongside the reference CRs in GitOps ZTP	You can now use custom CRs alongside the reference configuration CRs provided in the `ztp-site-generate` container. Adding custom content to the GitOps ZTP pipeline
Using custom node labels in the `SiteConfig` CR with GitOps ZTP	You can now use the `nodeLabels` field in the `SiteConfig` CR to create custom roles for nodes in managed clusters. Single-node OpenShift SiteConfig CR installation reference
Intel Westport Channel e810 NIC as PTP Grandmaster clock (Technology Preview)	You can use the Intel Westport Channel E810-XXVDA4T as a GNSS-sourced grandmaster clock. The NIC is automatically configured by the PTP Operator with the E810 hardware plugin. Configuring linuxptp services as a grandmaster clock for dual E810 Westport Channel NICs
PTP Operator hardware specific functionality plugin (Technology Preview)	A new E810 NIC hardware plugin is now available in the PTP Operator. You can use the E810 plugin to configure the NIC directly. Intel Westport Channel E810 hardware configuration reference
PTP events and metrics	The `PtpConfig` reference configuration CRs have been updated. Discovering PTP capable network devices in your cluster
Precaching user-specified images	You can now precache application workload images before upgrading your applications on single-node OpenShift clusters with Topology Aware Lifecycle Manager. Precaching images for single-node OpenShift deployments
Using OpenShift capabilities to further reduce the single-node OpenShift DU footprint	Use cluster capabilities to enable or disable optional components before you install the cluster. In OpenShift Container Platform 4.14, the following optional capabilities are available: `image-registry`, `baremetal`, `marketplace`, `openshift-samples`, `Console`, `Insights`, `Storage`, `CSISnapshot`, `NodeTuning`, `MachineAPI`. The reference configuration includes only those features required for RAN DU. Cluster capabilities
Set `vectord` as the default log collector in the DU profile	single-node OpenShift clusters that run DU workloads require logging and log forwarding. Cluster logging and log forwarding

3.2.1.2. Deployment architecture overview

You deploy the telco RAN DU 4.14 reference configuration to managed clusters from a centrally managed RHACM hub cluster. The reference design specification (RDS) includes configuration of the managed clusters and the hub cluster components.

Figure 3.1. Telco RAN DU deployment architecture overview

A diagram showing two distinctive network far edge deployment processes

3.2.2. Telco RAN DU use model overview

Use the following information to plan telco RAN DU workloads, cluster resources, and hardware specifications for the hub cluster and managed single-node OpenShift clusters.

3.2.2.1. Telco RAN DU application workloads

DU worker nodes must have 3rd Generation Xeon (Ice Lake) 2.20 GHz or better CPUs with firmware tuned for maximum performance.

5G RAN DU user applications and workloads should conform to the following best practices and application limits:

Develop cloud-native network functions (CNFs) that conform to the latest version of the CNF best practices guide.
Use SR-IOV for high performance networking.
Use exec probes sparingly and only when no other suitable options are available
- Do not use exec probes if a CNF uses CPU pinning. Use other probe implementations, for example, httpGet or tcpSocket.
- When you need to use exec probes, limit the exec probe frequency and quantity. The maximum number of exec probes must be kept below 10, and frequency must not be set to less than 10 seconds.

Note

Startup probes require minimal resources during steady-state operation. The limitation on exec probes applies primarily to liveness and readiness probes.

3.2.2.2. Telco RAN DU representative reference application workload characteristics

The representative reference application workload has the following characteristics:

Has a maximum of 15 pods and 30 containers for the vRAN application including its management and control functions
Uses a maximum of 2 ConfigMap and 4 Secret CRs per pod
Uses a maximum of 10 exec probes with a frequency of not less than 10 seconds
Incremental application load on the kube-apiserver is less than 10% of the cluster platform usage
Note
You can extract CPU load can from the platform metrics. For example:
```
query=avg_over_time(pod:container_cpu_usage:sum{namespace="openshift-kube-apiserver"}[30m])
```
Application logs are not collected by the platform log collector
Aggregate traffic on the primary CNI is less than 1 MBps

3.2.2.3. Telco RAN DU worker node cluster resource utilization

The maximum number of running pods in the system, inclusive of application workloads and OpenShift Container Platform pods, is 120.

Resource utilization

OpenShift Container Platform resource utilization varies depending on many factors including application workload characteristics such as:

Pod count
Type and frequency of probes
Messaging rates on primary CNI or secondary CNI with kernel networking
API access rate
Logging rates
Storage IOPS

Cluster resource requirements are applicable under the following conditions:

The cluster is running the described representative application workload.
The cluster is managed with the constraints described in "Telco RAN DU worker node cluster resource utilization".
Components noted as optional in the RAN DU use model configuration are not applied.

Important

You will need to do additional analysis to determine the impact on resource utilization and ability to meet KPI targets for configurations outside the scope of the Telco RAN DU reference design. You might have to allocate additional resources in the cluster depending on your requirements.

Additional resources

Telco RAN DU 4.14 validated software components

3.2.2.4. Hub cluster management characteristics

Red Hat Advanced Cluster Management (RHACM) is the recommended cluster management solution. Configure it to the following limits on the hub cluster:

Configure a maximum of 5 RHACM policies with a compliant evaluation interval of at least 10 minutes.
Use a maximum of 10 managed cluster templates in policies. Where possible, use hub-side templating.
Disable all RHACM add-ons except for the policy-controller and observability-controller add-ons. Set Observability to the default configuration.
Important
Configuring optional components or enabling additional features will result in additional resource usage and can reduce overall system performance.
For more information, see Reference design deployment components.

Table 3.2. OpenShift platform resource utilization under reference application load
Metric	Limit	Notes
CPU usage	Less than 4000 mc – 2 cores (4 hyperthreads)	Platform CPU is pinned to reserved cores, including both hyperthreads in each reserved core. The system is engineered to use 3 CPUs (3000mc) at steady-state to allow for periodic system tasks and spikes.
Memory used	Less than 16G

3.2.2.5. Telco RAN DU RDS components

The following sections describe the various OpenShift Container Platform components and configurations that you use to configure and deploy clusters to run telco RAN DU workloads.

Figure 3.2. Telco RAN DU reference design components

A diagram describing the telco RAN DU component stack.

Note

Ensure that components that are not included in the telco RAN DU profile do not affect the CPU resources allocated to workload applications.

Important

Out of tree drivers are not supported.

Additional resources

For details of the telco RAN RDS KPI test results, see Telco RAN DU reference design specification KPI test results. This information is only available to customers and partners.

3.2.3. Telco RAN DU 4.14 reference design components

The following sections describe the various OpenShift Container Platform components and configurations that you use to configure and deploy clusters to run RAN DU workloads.

3.2.3.1. Host firmware tuning

New in this release

No reference design updates in this release

Description

Configure system level performance. See Configuring host firmware for low latency and high performance for recommended settings.

If Ironic inspection is enabled, the firmware setting values are available from the per-cluster BareMetalHost CR on the hub cluster. You enable Ironic inspection with a label in the spec.clusters.nodes field in the SiteConfig CR that you use to install the cluster. For example:

nodes:
  - hostName: "example-node1.example.com"
    ironicInspect: "enabled"

Note

The telco RAN DU reference SiteConfig does not enable the ironicInspect field by default.

Limits and requirements

Hyperthreading must be enabled

Engineering considerations

Tune all settings for maximum performance
Note
You can tune firmware selections for power savings at the expense of performance as required.

3.2.3.2. Node Tuning Operator

New in this release

No reference design updates in this release

Description

You tune the cluster performance by creating a performance profile. Settings that you configure with a performance profile include:

Selecting the realtime or non-realtime kernel.
Allocating cores to a reserved or isolated cpuset. OpenShift Container Platform processes allocated to the management workload partition are pinned to reserved set.
Enabling kubelet features (CPU manager, topology manager, and memory manager).
Configuring huge pages.
Setting additional kernel arguments.
Setting per-core power tuning and max CPU frequency.

Limits and requirements

The Node Tuning Operator uses the PerformanceProfile CR to configure the cluster. You need to configure the following settings in the RAN DU profile PerformanceProfile CR:

Select reserved and isolated cores and ensure that you allocate at least 4 hyperthreads (equivalent to 2 cores) on Intel 3rd Generation Xeon (Ice Lake) 2.20 GHz CPUs or better with firmware tuned for maximum performance.
Set the reserved cpuset to include both hyperthread siblings for each included core. Unreserved cores are available as allocatable CPU for scheduling workloads. Ensure that hyperthread siblings are not split across reserved and isolated cores.
Configure reserved and isolated CPUs to include all threads in all cores based on what you have set as reserved and isolated CPUs.
Set core 0 of each NUMA node to be included in the reserved CPU set.
Set the huge page size to 1G.

Note

You should not add additional workloads to the management partition. Only those pods which are part of the OpenShift management platform should be annotated into the management partition.

Engineering considerations

You should use the RT kernel to meet performance requirements.
Note
You can use the non-RT kernel if required.
The number of huge pages that you configure depends on the application workload requirements. Variation in this parameter is expected and allowed.
Variation is expected in the configuration of reserved and isolated CPU sets based on selected hardware and additional components in use on the system. Variation must still meet the specified limits.
Hardware without IRQ affinity support impacts isolated CPUs. To ensure that pods with guaranteed whole CPU QoS have full use of the allocated CPU, all hardware in the server must support IRQ affinity. For more information, see About support of IRQ affinity setting.

Note

In OpenShift Container Platform 4.14, any PerformanceProfile CR configured on the cluster causes the Node Tuning Operator to automatically set all cluster nodes to use cgroup v1.

For more information about cgroups, see Configuring Linux cgroup.

3.2.3.3. PTP Operator

New in this release

PTP grandmaster clock (T-GM) GPS timing with Intel E810-XXV-4T Westport Channel NIC – minimum firmware version 4.30 (Technology Preview)
PTP events and metrics for grandmaster (T-GM) are new in OpenShift Container Platform 4.14 (Technology Preview)

Description

Configure of PTP timing support for cluster nodes. The DU node can run in the following modes:

As an ordinary clock synced to a T-GM or boundary clock (T-BC)
As dual boundary clocks, one per NIC (high availability is not supported)
As grandmaster clock with support for E810 Westport Channel NICs (Technology Preview)
Optionally as a boundary clock for radio units (RUs)

Optional: subscribe applications to PTP events that happen on the node that the application is running. You subscribe the application to events via HTTP.

Limits and requirements

High availability is not supported with dual NIC configurations.
Westport Channel NICs configured as T-GM do not support DPLL with the current ice driver version.
GPS offsets are not reported. Use a default offset of less than or equal to 5.
DPLL offsets are not reported. Use a default offset of less than or equal to 5.

Engineering considerations

Configurations are provided for ordinary clock, boundary clock, or grandmaster clock
PTP fast event notifications uses ConfigMap CRs to store PTP event subscriptions
Use Intel E810-XXV-4T Westport Channel NICs for PTP grandmaster clocks with GPS timing, minimum firmware version 4.40

3.2.3.4. SR-IOV Operator

New in this release

No reference design updates in this release

Description

The SR-IOV Operator provisions and configures the SR-IOV CNI and device plugins. Both netdevice (kernel VFs) and vfio (DPDK) devices are supported.

Engineering considerations

Customer variation on the configuration and number of SriovNetwork and SriovNetworkNodePolicy custom resources (CRs) is expected.
IOMMU kernel command line settings are applied with a MachineConfig CR at install time. This ensures that the SriovOperator CR does not cause a reboot of the node when adding them.

3.2.3.5. Logging

New in this release

Vector is now the recommended log collector.

Description

Use logging to collect logs from the far edge node for remote analysis.

Engineering considerations

Handling logs beyond the infrastructure and audit logs, for example, from the application workload requires additional CPU and network bandwidth based on additional logging rate.
As of OpenShift Container Platform 4.14, vector is the reference log collector.
Note
Use of fluentd in the RAN use model is deprecated.

3.2.3.6. SRIOV-FEC Operator

New in this release

No reference design updates in this release

Description

SRIOV-FEC Operator is an optional 3rd party Certified Operator supporting FEC accelerator hardware.

Limits and requirements

Starting with FEC Operator v2.7.0:
- SecureBoot is supported
- The vfio driver for the PF requires the usage of vfio-token that is injected into Pods. The VF token can be passed to DPDK by using the EAL parameter --vfio-vf-token.

Engineering considerations

The SRIOV-FEC Operator uses CPU cores from the isolated CPU set.
You can validate FEC readiness as part of the pre-checks for application deployment, for example, by extending the validation policy.

3.2.3.7. Local Storage Operator

New in this release

No reference design updates in this release

Description

You can create persistent volumes that can be used as PVC resources by applications with the Local Storage Operator. The number and type of PV resources that you create depends on your requirements.

Engineering considerations

Create backing storage for PV CRs before creating the PV. This can be a partition, a local volume, LVM volume, or full disk.
Refer to the device listing in LocalVolume CRs by the hardware path used to access each device to ensure correct allocation of disks and partitions. Logical names (for example, /dev/sda) are not guaranteed to be consistent across node reboots.
For more information, see the RHEL 9 documentation on device identifiers.

3.2.3.8. LVMS Operator

New in this release

No reference design updates in this release

New in this release

Simplified LVMS deviceSelector logic
LVM Storage with ext4 and PV resources

Note

LVMS Operator is an optional component.

Description

The LVMS Operator provides dynamic provisioning of block and file storage. The LVMS Operator creates logical volumes from local devices that can be used as PVC resources by applications. Volume expansion and snapshots are also possible.

The following example configuration creates a vg1 volume group that leverages all available disks on the node except the installation disk:

StorageLVMCluster.yaml

apiVersion: lvm.topolvm.io/v1alpha1
kind: LVMCluster
metadata:
  name: storage-lvmcluster
  namespace: openshift-storage
  annotations:
    ran.openshift.io/ztp-deploy-wave: "10"
spec: {}
  storage:
    deviceClasses:
    - name: vg1
      thinPoolConfig:
        name: thin-pool-1
        sizePercent: 90
        overprovisionRatio: 10

Limits and requirements

In single-node OpenShift clusters, persistent storage must be provided by either LVMS or Local Storage, not both.

Engineering considerations

The LVMS Operator is not the reference storage solution for the DU use case. If you require LVMS Operator for application workloads, the resource use is accounted for against the application cores.
Ensure that sufficient disks or partitions are available for storage requirements.

3.2.3.9. Workload partitioning

New in this release

No reference design updates in this release

Description

Workload partitioning pins OpenShift platform and Day 2 Operator pods that are part of the DU profile to the reserved cpuset and removes the reserved CPU from node accounting. This leaves all unreserved CPU cores available for user workloads.

The method of enabling and configuring workload partitioning changed in OpenShift Container Platform 4.14.

4.14 and later

Configure partitions by setting installation parameters:
```
cpuPartitioningMode: AllNodes
```
Configure management partition cores with the reserved CPU set in the PerformanceProfile CR

4.13 and earlier

Configure partitions with extra MachineConfiguration CRs applied at install-time

Limits and requirements

Namespace and Pod CRs must be annotated to allow the pod to be applied to the management partition
Pods with CPU limits cannot be allocated to the partition. This is because mutation can change the pod QoS.
For more information about the minimum number of CPUs that can be allocated to the management partition, see Node Tuning Operator.

Engineering considerations

Workload Partitioning pins all management pods to reserved cores. A sufficient number of cores must be allocated to the reserved set to account for operating system, management pods, and expected spikes in CPU use that occur when the workload starts, the node reboots, or other system events happen.

3.2.3.10. Cluster tuning

New in this release

You can remove the Image Registry Operator by using the cluster capabilities feature.
Note
You configure cluster capabilities by using the spec.clusters.installConfigOverrides field in the SiteConfig CR that you use to install the cluster.

Description

The cluster capabilities feature now includes a MachineAPI component which, when excluded, disables the following Operators and their resources in the cluster:

openshift/cluster-autoscaler-operator
openshift/cluster-control-plane-machine-set-operator
openshift/machine-api-operator

Limits and requirements

Cluster capabilities are not available for installer-provisioned installation methods.

You must apply all platform tuning configurations. The following table lists the required platform tuning configurations:

Table 3.3. Cluster capabilities configurations
Feature	Description
Remove optional cluster capabilities	Reduce the OpenShift Container Platform footprint by disabling optional cluster Operators on single-node OpenShift clusters only. Remove all optional Operators except the Marketplace and Node Tuning Operators.
Configure cluster monitoring	Configure the monitoring stack for reduced footprint by doing the following: Disable the local `alertmanager` and `telemeter` components. If you use RHACM observability, the CR must be augmented with appropriate `additionalAlertManagerConfigs` CRs to forward alerts to the hub cluster. Reduce the `Prometheus` retention period to 24h. Note The RHACM hub cluster aggregates managed cluster metrics.
Disable networking diagnostics	Disable networking diagnostics for single-node OpenShift because they are not required.
Configure a single Operator Hub catalog source	Configure the cluster to use a single catalog source that contains only the Operators required for a RAN DU deployment. Each catalog source increases the CPU use on the cluster. Using a single `CatalogSource` fits within the platform CPU budget.

3.2.3.11. Machine configuration

New in this release

Set rcu_normal after node recovery

Limits and requirements

The CRI-O wipe disable MachineConfig assumes that images on disk are static other than during scheduled maintenance in defined maintenance windows. To ensure the images are static, do not set the pod imagePullPolicy field to Always.

Table 3.4. Machine configuration options
Feature	Description
Container runtime	Sets the container runtime to `crun` for all node roles.
kubelet config and container mount hiding	Reduces the frequency of kubelet housekeeping and eviction monitoring to reduce CPU usage. Create a container mount namespace, visible to kubelet and CRI-O, to reduce system mount scanning resource usage.
SCTP	Optional configuration (enabled by default) Enables SCTP. SCTP is required by RAN applications but disabled by default in RHCOS.
kdump	Optional configuration (enabled by default) Enables kdump to capture debug information when a kernel panic occurs.
CRI-O wipe disable	Disables automatic wiping of the CRI-O image cache after unclean shutdown.
SR-IOV-related kernel arguments	Includes additional SR-IOV related arguments in the kernel command line.
RCU Normal systemd service	Sets `rcu_normal` after the system is fully started.
One-shot time sync	Runs a one-time system time synchronization job for control plane or worker nodes.

3.2.3.12. Reference design deployment components

The following sections describe the various OpenShift Container Platform components and configurations that you use to configure the hub cluster with Red Hat Advanced Cluster Management (RHACM).

3.2.3.12.1. Red Hat Advanced Cluster Management (RHACM)

New in this release

Additional node labels can be configured during installation.

Description

RHACM provides Multi Cluster Engine (MCE) installation and ongoing lifecycle management functionality for deployed clusters. You declaratively specify configurations and upgrades with Policy CRs and apply the policies to clusters with the RHACM policy controller as managed by Topology Aware Lifecycle Manager.

GitOps Zero Touch Provisioning (ZTP) uses the MCE feature of RHACM
Configuration, upgrades, and cluster status are managed with the RHACM policy controller

Limits and requirements

A single hub cluster supports up to 3500 deployed single-node OpenShift clusters with 5 Policy CRs bound to each cluster.

Engineering considerations

Cluster specific configuration: managed clusters typically have some number of configuration values that are specific to the individual cluster. These configurations should be managed using RHACM policy hub-side templating with values pulled from ConfigMap CRs based on the cluster name.
To save CPU resources on managed clusters, policies that apply static configurations should be unbound from managed clusters after GitOps ZTP installation of the cluster. For more information, see Release a persistent volume.

3.2.3.12.2. Topology Aware Lifecycle Manager (TALM)

New in this release

Added support for pre-caching additional user-specified images

Description

Managed updates

TALM is an Operator that runs only on the hub cluster for managing how changes (including cluster and Operator upgrades, configuration, and so on) are rolled out to the network. TALM does the following:

Progressively applies updates to fleets of clusters in user-configurable batches by using Policy CRs.
Adds ztp-done labels or other user configurable labels on a per-cluster basis

Precaching for single-node OpenShift clusters

TALM supports optional precaching of OpenShift Container Platform, OLM Operator, and additional user images to single-node OpenShift clusters before initiating an upgrade.

A new PreCachingConfig custom resource is available for specifying optional pre-caching configurations. For example:

apiVersion: ran.openshift.io/v1alpha1
kind: PreCachingConfig
metadata:
  name: example-config
  namespace: example-ns
spec:
  additionalImages:
    - quay.io/foobar/application1@sha256:3d5800990dee7cd4727d3fe238a97e2d2976d3808fc925ada29c559a47e2e
    - quay.io/foobar/application2@sha256:3d5800123dee7cd4727d3fe238a97e2d2976d3808fc925ada29c559a47adf
    - quay.io/foobar/applicationN@sha256:4fe1334adfafadsf987123adfffdaf1243340adfafdedga0991234afdadfs
  spaceRequired: 45 GiB 1
  overrides:
    preCacheImage: quay.io/test_images/pre-cache:latest
    platformImage: quay.io/openshift-release-dev/ocp-release@sha256:3d5800990dee7cd4727d3fe238a97e2d2976d3808fc925ada29c559a47e2e
  operatorsIndexes:
    - registry.example.com:5000/custom-redhat-operators:1.0.0
  operatorsPackagesAndChannels:
    - local-storage-operator: stable
    - ptp-operator: stable
    - sriov-network-operator: stable
  excludePrecachePatterns: 2
    - aws
    - vsphere

1 1: Configurable space-required parameter allows you to validate before and after pre-caching storage space
2: Configurable filtering allows exclusion of unused images

Backup and restore for single-node OpenShift

TALM supports taking a snapshot of the cluster operating system and configuration to a dedicated partition on a local disk. A restore script is provided that returns the cluster to the backed up state.

Limits and requirements

TALM supports concurrent cluster deployment in batches of 400
Precaching and backup features are for single-node OpenShift clusters only.

Engineering considerations

The PreCachingConfig CR is optional and does not need to be created if you just wants to precache platform related (OpenShift and OLM Operator) images. The PreCachingConfig CR must be applied before referencing it in the ClusterGroupUpgrade CR.
Create a recovery partition during installation if you opt to use the TALM backup and restore feature.

3.2.3.12.3. GitOps and GitOps ZTP plugins

New in this release

GA support for inclusion of user-provided CRs in Git for GitOps ZTP deployments
GitOps ZTP independence from the deployed cluster version

Description

GitOps and GitOps ZTP plugins provide a GitOps-based infrastructure for managing cluster deployment and configuration. Cluster definitions and configurations are maintained as a declarative state in Git. ZTP plugins provide support for generating installation CRs from the SiteConfig CR and automatic wrapping of configuration CRs in policies based on PolicyGenTemplate CRs.

You can deploy and manage multiple versions of OpenShift Container Platform on managed clusters with the baseline reference configuration CRs in a /source-crs subdirectory provided that subdirectory also contains the kustomization.yaml file. You add user-provided CRs to this subdirectory that you use with the predefined CRs that are specified in the PolicyGenTemplate CRs. This allows you to tailor your configurations to suit your specific requirements and provides GitOps ZTP version independence between managed clusters and the hub cluster.

For more information, see the following:

Preparing the site configuration repository for version independence
Adding custom content to the GitOps ZTP pipeline

Limits

300 SiteConfig CRs per ArgoCD application. You can use multiple applications to achieve the maximum number of clusters supported by a single hub cluster.
Content in the /source-crs folder in Git overrides content provided in the GitOps ZTP plugin container. Git takes precedence in the search path.
Add the /source-crs folder in the same directory as the kustomization.yaml file, which includes the PolicyGenTemplate as a generator.
Note
Alternative locations for the /source-crs directory are not supported in this context.

Engineering considerations

To avoid confusion or unintentional overwriting of files when updating content, use unique and distinguishable names for user-provided CRs in the /source-crs folder and extra manifests in Git.
The SiteConfig CR allows multiple extra-manifest paths. When files with the same name are found in multiple directory paths, the last file found takes precedence. This allows the full set of version specific Day 0 manifests (extra-manifests) to be placed in Git and referenced from the SiteConfig. With this feature, you can deploy multiple OpenShift Container Platform versions to managed clusters simultaneously.
The extraManifestPath field of the SiteConfig CR is deprecated from OpenShift Container Platform 4.15 and later. Use the new extraManifests.searchPaths field instead.

3.2.3.12.4. Agent-based installer

New in this release

No reference design updates in this release

Description

Agent-based installer (ABI) provides installation capabilities without centralized infrastructure. The installation program creates an ISO image that you mount to the server. When the server boots it installs OpenShift Container Platform and supplied extra manifests.

Note

You can also use ABI to install OpenShift Container Platform clusters without a hub cluster. An image registry is still required when you use ABI in this manner.

Agent-based installer (ABI) is an optional component.

Limits and requirements

You can supply a limited set of additional manifests at installation time.
You must include MachineConfiguration CRs that are required by the RAN DU use case.

Engineering considerations

ABI provides a baseline OpenShift Container Platform installation.
You install Day 2 Operators and the remainder of the RAN DU use case configurations after installation.

3.2.3.13. Additional components

3.2.3.13.1. Bare Metal Event Relay

The Bare Metal Event Relay is an optional Operator that runs exclusively on the managed spoke cluster. It relays Redfish hardware events to cluster applications.

Note

The Bare Metal Event Relay is not included in the RAN DU use model reference configuration and is an optional feature. If you want to use the Bare Metal Event Relay, assign additional CPU resources from the application CPU budget.

3.2.4. Telco RAN distributed unit (DU) reference configuration CRs

Use the following custom resources (CRs) to configure and deploy OpenShift Container Platform clusters with the telco RAN DU profile. Some of the CRs are optional depending on your requirements. CR fields you can change are annotated in the CR with YAML comments.

Note

You can extract the complete set of RAN DU CRs from the ztp-site-generate container image. See Preparing the GitOps ZTP site configuration repository for more information.

3.2.4.1. Day 2 Operators reference CRs

Table 3.5. Day 2 Operators CRs
Component	Reference CR	Optional	New in this release
Cluster logging	ClusterLogForwarder.yaml	No	No
Cluster logging	ClusterLogging.yaml	No	No
Cluster logging	ClusterLogNS.yaml	No	No
Cluster logging	ClusterLogOperGroup.yaml	No	No
Cluster logging	ClusterLogSubscription.yaml	No	No
Local Storage Operator	StorageClass.yaml	Yes	No
Local Storage Operator	StorageLV.yaml	Yes	No
Local Storage Operator	StorageNS.yaml	Yes	No
Local Storage Operator	StorageOperGroup.yaml	Yes	No
Local Storage Operator	StorageSubscription.yaml	Yes	No
Node Tuning Operator	PerformanceProfile.yaml	No	No
Node Tuning Operator	TunedPerformancePatch.yaml	No	No
PTP fast event notifications	PtpOperatorConfigForEvent.yaml	Yes	No
PTP Operator	PtpConfigBoundary.yaml	No	No
PTP Operator	PtpConfigGmWpc.yaml	No	Yes
PTP Operator	PtpConfigSlave.yaml	No	No
PTP Operator	PtpSubscription.yaml	No	No
PTP Operator	PtpSubscriptionNS.yaml	No	No
PTP Operator	PtpSubscriptionOperGroup.yaml	No	No
SR-IOV FEC Operator	AcceleratorsNS.yaml	Yes	No
SR-IOV FEC Operator	AcceleratorsOperGroup.yaml	Yes	No
SR-IOV FEC Operator	AcceleratorsSubscription.yaml	Yes	No
SR-IOV FEC Operator	SriovFecClusterConfig.yaml	Yes	No
SR-IOV Operator	SriovNetwork.yaml	No	No
SR-IOV Operator	SriovNetworkNodePolicy.yaml	No	No
SR-IOV Operator	SriovOperatorConfig.yaml	No	No
SR-IOV Operator	SriovSubscription.yaml	No	No
SR-IOV Operator	SriovSubscriptionNS.yaml	No	No
SR-IOV Operator	SriovSubscriptionOperGroup.yaml	No	No

3.2.4.2. Cluster tuning reference CRs

Table 3.6. Cluster tuning CRs
Component	Reference CR	Optional	New in this release
Cluster capabilities	example-sno.yaml	No	No
Disabling network diagnostics	DisableSnoNetworkDiag.yaml	No	No
Monitoring configuration	ReduceMonitoringFootprint.yaml	No	No
OperatorHub	DefaultCatsrc.yaml	No	No
OperatorHub	DisconnectedICSP.yaml	No	No
OperatorHub	OperatorHub.yaml	No	No

3.2.4.3. Machine configuration reference CRs

Table 3.7. Machine configuration CRs
Component	Reference CR	Optional	New in this release
Container runtime (crun)	enable-crun-master.yaml	No	No
Container runtime (crun)	enable-crun-worker.yaml	No	No
Disabling CRI-O wipe	99-crio-disable-wipe-master.yaml	No	No
Disabling CRI-O wipe	99-crio-disable-wipe-worker.yaml	No	No
Enabling kdump	05-kdump-config-master.yaml	No	Yes
Enabling kdump	05-kdump-config-worker.yaml	No	Yes
Enabling kdump	06-kdump-master.yaml	No	No
Enabling kdump	06-kdump-worker.yaml	No	No
Kubelet configuration and container mount hiding	01-container-mount-ns-and-kubelet-conf-master.yaml	No	No
Kubelet configuration and container mount hiding	01-container-mount-ns-and-kubelet-conf-worker.yaml	No	No
One-shot time sync	99-sync-time-once-master.yaml	No	Yes
One-shot time sync	99-sync-time-once-worker.yaml	No	Yes
SCTP	03-sctp-machine-config-master.yaml	No	No
SCTP	03-sctp-machine-config-worker.yaml	No	No
SR-IOV related kernel arguments	07-sriov-related-kernel-args-master.yaml	No	Yes

3.2.4.4. YAML reference

The following is a complete reference for all the custom resources (CRs) that make up the telco RAN DU 4.14 reference configuration.

3.2.4.4.1. Day 2 Operators reference YAML

ClusterLogForwarder.yaml

apiVersion: "logging.openshift.io/v1"
kind: ClusterLogForwarder
metadata:
  name: instance
  namespace: openshift-logging
  annotations: {}
spec:
  outputs: $outputs
  pipelines: $pipelines

ClusterLogging.yaml

apiVersion: logging.openshift.io/v1
kind: ClusterLogging
metadata:
  name: instance
  namespace: openshift-logging
  annotations: {}
spec:
  managementState: "Managed"
  collection:
    logs:
      type: "vector"

ClusterLogNS.yaml

---
apiVersion: v1
kind: Namespace
metadata:
  name: openshift-logging
  annotations:
    workload.openshift.io/allowed: management

ClusterLogOperGroup.yaml

---
apiVersion: operators.coreos.com/v1
kind: OperatorGroup
metadata:
  name: cluster-logging
  namespace: openshift-logging
  annotations: {}
spec:
  targetNamespaces:
    - openshift-logging

ClusterLogSubscription.yaml

apiVersion: operators.coreos.com/v1alpha1
kind: Subscription
metadata:
  name: cluster-logging
  namespace: openshift-logging
  annotations: {}
spec:
  channel: "stable"
  name: cluster-logging
  source: redhat-operators-disconnected
  sourceNamespace: openshift-marketplace
  installPlanApproval: Manual
status:
  state: AtLatestKnown

StorageClass.yaml

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  annotations: {}
  name: example-storage-class
provisioner: kubernetes.io/no-provisioner
reclaimPolicy: Delete

StorageLV.yaml

apiVersion: "local.storage.openshift.io/v1"
kind: "LocalVolume"
metadata:
  name: "local-disks"
  namespace: "openshift-local-storage"
  annotations: {}
spec:
  logLevel: Normal
  managementState: Managed
  storageClassDevices:
    # The list of storage classes and associated devicePaths need to be specified like this example:
    - storageClassName: "example-storage-class"
      volumeMode: Filesystem
      fsType: xfs
      # The below must be adjusted to the hardware.
      # For stability and reliability, it's recommended to use persistent
      # naming conventions for devicePaths, such as /dev/disk/by-path.
      devicePaths:
        - /dev/disk/by-path/pci-0000:05:00.0-nvme-1
#---
## How to verify
## 1. Create a PVC
# apiVersion: v1
# kind: PersistentVolumeClaim
# metadata:
#   name: local-pvc-name
# spec:
#   accessModes:
#   - ReadWriteOnce
#   volumeMode: Filesystem
#   resources:
#     requests:
#       storage: 100Gi
#   storageClassName: example-storage-class
#---
## 2. Create a pod that mounts it
# apiVersion: v1
# kind: Pod
# metadata:
#   labels:
#     run: busybox
#   name: busybox
# spec:
#   containers:
#   - image: quay.io/quay/busybox:latest
#     name: busybox
#     resources: {}
#     command: ["/bin/sh", "-c", "sleep infinity"]
#     volumeMounts:
#     - name: local-pvc
#       mountPath: /data
#   volumes:
#   - name: local-pvc
#     persistentVolumeClaim:
#       claimName: local-pvc-name
#   dnsPolicy: ClusterFirst
#   restartPolicy: Always
## 3. Run the pod on the cluster and verify the size and access of the `/data` mount

StorageNS.yaml

apiVersion: v1
kind: Namespace
metadata:
  name: openshift-local-storage
  annotations:
    workload.openshift.io/allowed: management

StorageOperGroup.yaml

apiVersion: operators.coreos.com/v1
kind: OperatorGroup
metadata:
  name: openshift-local-storage
  namespace: openshift-local-storage
  annotations: {}
spec:
  targetNamespaces:
    - openshift-local-storage

StorageSubscription.yaml

apiVersion: operators.coreos.com/v1alpha1
kind: Subscription
metadata:
  name: local-storage-operator
  namespace: openshift-local-storage
  annotations: {}
spec:
  channel: "stable"
  name: local-storage-operator
  source: redhat-operators-disconnected
  sourceNamespace: openshift-marketplace
  installPlanApproval: Manual
status:
  state: AtLatestKnown

PerformanceProfile.yaml

apiVersion: performance.openshift.io/v2
kind: PerformanceProfile
metadata:
  # if you change this name make sure the 'include' line in TunedPerformancePatch.yaml
  # matches this name: include=openshift-node-performance-${PerformanceProfile.metadata.name}
  # Also in file 'validatorCRs/informDuValidator.yaml':
  # name: 50-performance-${PerformanceProfile.metadata.name}
  name: openshift-node-performance-profile
  annotations:
    ran.openshift.io/reference-configuration: "ran-du.redhat.com"
spec:
  additionalKernelArgs:
    - "rcupdate.rcu_normal_after_boot=0"
    - "efi=runtime"
    - "vfio_pci.enable_sriov=1"
    - "vfio_pci.disable_idle_d3=1"
    - "module_blacklist=irdma"
  cpu:
    isolated: $isolated
    reserved: $reserved
  hugepages:
    defaultHugepagesSize: $defaultHugepagesSize
    pages:
      - size: $size
        count: $count
        node: $node
  machineConfigPoolSelector:
    pools.operator.machineconfiguration.openshift.io/$mcp: ""
  nodeSelector:
    node-role.kubernetes.io/$mcp: ""
  numa:
    topologyPolicy: "restricted"
  # To use the standard (non-realtime) kernel, set enabled to false
  realTimeKernel:
    enabled: true
  workloadHints:
    # WorkloadHints defines the set of upper level flags for different type of workloads.
    # See https://github.com/openshift/cluster-node-tuning-operator/blob/master/docs/performanceprofile/performance_profile.md#workloadhints
    # for detailed descriptions of each item.
    # The configuration below is set for a low latency, performance mode.
    realTime: true
    highPowerConsumption: false
    perPodPowerManagement: false

TunedPerformancePatch.yaml

apiVersion: tuned.openshift.io/v1
kind: Tuned
metadata:
  name: performance-patch
  namespace: openshift-cluster-node-tuning-operator
  annotations: {}
spec:
  profile:
    - name: performance-patch
      # Please note:
      # - The 'include' line must match the associated PerformanceProfile name, following below pattern
      #   include=openshift-node-performance-${PerformanceProfile.metadata.name}
      # - When using the standard (non-realtime) kernel, remove the kernel.timer_migration override from
      #   the [sysctl] section and remove the entire section if it is empty.
      data: |
        [main]
        summary=Configuration changes profile inherited from performance created tuned
        include=openshift-node-performance-openshift-node-performance-profile
        [sysctl]
        kernel.timer_migration=1
        [scheduler]
        group.ice-ptp=0:f:10:*:ice-ptp.*
        group.ice-gnss=0:f:10:*:ice-gnss.*
        [service]
        service.stalld=start,enable
        service.chronyd=stop,disable
  recommend:
    - machineConfigLabels:
        machineconfiguration.openshift.io/role: "$mcp"
      priority: 19
      profile: performance-patch

PtpOperatorConfigForEvent.yaml

apiVersion: ptp.openshift.io/v1
kind: PtpOperatorConfig
metadata:
  name: default
  namespace: openshift-ptp
  annotations: {}
spec:
  daemonNodeSelector:
    node-role.kubernetes.io/$mcp: ""
  ptpEventConfig:
    enableEventPublisher: true
    transportHost: "http://ptp-event-publisher-service-NODE_NAME.openshift-ptp.svc.cluster.local:9043"

PtpConfigBoundary.yaml

apiVersion: ptp.openshift.io/v1
kind: PtpConfig
metadata:
  name: boundary
  namespace: openshift-ptp
  annotations: {}
spec:
  profile:
    - name: "boundary"
      ptp4lOpts: "-2"
      phc2sysOpts: "-a -r -n 24"
      ptpSchedulingPolicy: SCHED_FIFO
      ptpSchedulingPriority: 10
      ptpSettings:
        logReduce: "true"
      ptp4lConf: |
        # The interface name is hardware-specific
        [$iface_slave]
        masterOnly 0
        [$iface_master_1]
        masterOnly 1
        [$iface_master_2]
        masterOnly 1
        [$iface_master_3]
        masterOnly 1
        [global]
        #
        # Default Data Set
        #
        twoStepFlag 1
        slaveOnly 0
        priority1 128
        priority2 128
        domainNumber 24
        #utc_offset 37
        clockClass 248
        clockAccuracy 0xFE
        offsetScaledLogVariance 0xFFFF
        free_running 0
        freq_est_interval 1
        dscp_event 0
        dscp_general 0
        dataset_comparison G.8275.x
        G.8275.defaultDS.localPriority 128
        #
        # Port Data Set
        #
        logAnnounceInterval -3
        logSyncInterval -4
        logMinDelayReqInterval -4
        logMinPdelayReqInterval -4
        announceReceiptTimeout 3
        syncReceiptTimeout 0
        delayAsymmetry 0
        fault_reset_interval -4
        neighborPropDelayThresh 20000000
        masterOnly 0
        G.8275.portDS.localPriority 128
        #
        # Run time options
        #
        assume_two_step 0
        logging_level 6
        path_trace_enabled 0
        follow_up_info 0
        hybrid_e2e 0
        inhibit_multicast_service 0
        net_sync_monitor 0
        tc_spanning_tree 0
        tx_timestamp_timeout 50
        unicast_listen 0
        unicast_master_table 0
        unicast_req_duration 3600
        use_syslog 1
        verbose 0
        summary_interval 0
        kernel_leap 1
        check_fup_sync 0
        clock_class_threshold 135
        #
        # Servo Options
        #
        pi_proportional_const 0.0
        pi_integral_const 0.0
        pi_proportional_scale 0.0
        pi_proportional_exponent -0.3
        pi_proportional_norm_max 0.7
        pi_integral_scale 0.0
        pi_integral_exponent 0.4
        pi_integral_norm_max 0.3
        step_threshold 2.0
        first_step_threshold 0.00002
        max_frequency 900000000
        clock_servo pi
        sanity_freq_limit 200000000
        ntpshm_segment 0
        #
        # Transport options
        #
        transportSpecific 0x0
        ptp_dst_mac 01:1B:19:00:00:00
        p2p_dst_mac 01:80:C2:00:00:0E
        udp_ttl 1
        udp6_scope 0x0E
        uds_address /var/run/ptp4l
        #
        # Default interface options
        #
        clock_type BC
        network_transport L2
        delay_mechanism E2E
        time_stamping hardware
        tsproc_mode filter
        delay_filter moving_median
        delay_filter_length 10
        egressLatency 0
        ingressLatency 0
        boundary_clock_jbod 0
        #
        # Clock description
        #
        productDescription ;;
        revisionData ;;
        manufacturerIdentity 00:00:00
        userDescription ;
        timeSource 0xA0
  recommend:
    - profile: "boundary"
      priority: 4
      match:
        - nodeLabel: "node-role.kubernetes.io/$mcp"

PtpConfigGmWpc.yaml

# The grandmaster profile is provided for testing only
# It is not installed on production clusters
apiVersion: ptp.openshift.io/v1
kind: PtpConfig
metadata:
  name: grandmaster
  namespace: openshift-ptp
  annotations: {}
spec:
  profile:
    - name: "grandmaster"
      ptp4lOpts: "-2 --summary_interval -4"
      phc2sysOpts: -r -u 0 -m -O -37 -N 8 -R 16 -s $iface_master -n 24
      ptpSchedulingPolicy: SCHED_FIFO
      ptpSchedulingPriority: 10
      ptpSettings:
        logReduce: "true"
      plugins:
        e810:
          enableDefaultConfig: false
          settings:
            LocalMaxHoldoverOffSet: 1500
            LocalHoldoverTimeout: 14400
            MaxInSpecOffset: 100
          pins: $e810_pins
          #  "$iface_master":
          #    "U.FL2": "0 2"
          #    "U.FL1": "0 1"
          #    "SMA2": "0 2"
          #    "SMA1": "0 1"
          ublxCmds:
            - args: #ubxtool -P 29.20 -z CFG-HW-ANT_CFG_VOLTCTRL,1
                - "-P"
                - "29.20"
                - "-z"
                - "CFG-HW-ANT_CFG_VOLTCTRL,1"
              reportOutput: false
            - args: #ubxtool -P 29.20 -e GPS
                - "-P"
                - "29.20"
                - "-e"
                - "GPS"
              reportOutput: false
            - args: #ubxtool -P 29.20 -d Galileo
                - "-P"
                - "29.20"
                - "-d"
                - "Galileo"
              reportOutput: false
            - args: #ubxtool -P 29.20 -d GLONASS
                - "-P"
                - "29.20"
                - "-d"
                - "GLONASS"
              reportOutput: false
            - args: #ubxtool -P 29.20 -d BeiDou
                - "-P"
                - "29.20"
                - "-d"
                - "BeiDou"
              reportOutput: false
            - args: #ubxtool -P 29.20 -d SBAS
                - "-P"
                - "29.20"
                - "-d"
                - "SBAS"
              reportOutput: false
            - args: #ubxtool -P 29.20 -t -w 5 -v 1 -e SURVEYIN,600,50000
                - "-P"
                - "29.20"
                - "-t"
                - "-w"
                - "5"
                - "-v"
                - "1"
                - "-e"
                - "SURVEYIN,600,50000"
              reportOutput: true
            - args: #ubxtool -P 29.20 -p MON-HW
                - "-P"
                - "29.20"
                - "-p"
                - "MON-HW"
              reportOutput: true
            - args: #ubxtool -P 29.20 -p CFG-MSG,1,38,300
                - "-P"
                - "29.20"
                - "-p"
                - "CFG-MSG,1,38,300"
              reportOutput: true
      ts2phcOpts: " "
      ts2phcConf: |
        [nmea]
        ts2phc.master 1
        [global]
        use_syslog  0
        verbose 1
        logging_level 7
        ts2phc.pulsewidth 100000000
        #GNSS module s /dev/ttyGNSS* -al use _0
        #cat /dev/ttyGNSS_1700_0 to find available serial port
        #example value of gnss_serialport is /dev/ttyGNSS_1700_0
        ts2phc.nmea_serialport $gnss_serialport
        leapfile  /usr/share/zoneinfo/leap-seconds.list
        [$iface_master]
        ts2phc.extts_polarity rising
        ts2phc.extts_correction 0
      ptp4lConf: |
        [$iface_master]
        masterOnly 1
        [$iface_master_1]
        masterOnly 1
        [$iface_master_2]
        masterOnly 1
        [$iface_master_3]
        masterOnly 1
        [global]
        #
        # Default Data Set
        #
        twoStepFlag 1
        priority1 128
        priority2 128
        domainNumber 24
        #utc_offset 37
        clockClass 6
        clockAccuracy 0x27
        offsetScaledLogVariance 0xFFFF
        free_running 0
        freq_est_interval 1
        dscp_event 0
        dscp_general 0
        dataset_comparison G.8275.x
        G.8275.defaultDS.localPriority 128
        #
        # Port Data Set
        #
        logAnnounceInterval -3
        logSyncInterval -4
        logMinDelayReqInterval -4
        logMinPdelayReqInterval 0
        announceReceiptTimeout 3
        syncReceiptTimeout 0
        delayAsymmetry 0
        fault_reset_interval -4
        neighborPropDelayThresh 20000000
        masterOnly 0
        G.8275.portDS.localPriority 128
        #
        # Run time options
        #
        assume_two_step 0
        logging_level 6
        path_trace_enabled 0
        follow_up_info 0
        hybrid_e2e 0
        inhibit_multicast_service 0
        net_sync_monitor 0
        tc_spanning_tree 0
        tx_timestamp_timeout 50
        unicast_listen 0
        unicast_master_table 0
        unicast_req_duration 3600
        use_syslog 1
        verbose 0
        summary_interval -4
        kernel_leap 1
        check_fup_sync 0
        clock_class_threshold 7
        #
        # Servo Options
        #
        pi_proportional_const 0.0
        pi_integral_const 0.0
        pi_proportional_scale 0.0
        pi_proportional_exponent -0.3
        pi_proportional_norm_max 0.7
        pi_integral_scale 0.0
        pi_integral_exponent 0.4
        pi_integral_norm_max 0.3
        step_threshold 2.0
        first_step_threshold 0.00002
        clock_servo pi
        sanity_freq_limit  200000000
        ntpshm_segment 0
        #
        # Transport options
        #
        transportSpecific 0x0
        ptp_dst_mac 01:1B:19:00:00:00
        p2p_dst_mac 01:80:C2:00:00:0E
        udp_ttl 1
        udp6_scope 0x0E
        uds_address /var/run/ptp4l
        #
        # Default interface options
        #
        clock_type BC
        network_transport L2
        delay_mechanism E2E
        time_stamping hardware
        tsproc_mode filter
        delay_filter moving_median
        delay_filter_length 10
        egressLatency 0
        ingressLatency 0
        boundary_clock_jbod 0
        #
        # Clock description
        #
        productDescription ;;
        revisionData ;;
        manufacturerIdentity 00:00:00
        userDescription ;
        timeSource 0x20
  recommend:
    - profile: "grandmaster"
      priority: 4
      match:
        - nodeLabel: "node-role.kubernetes.io/$mcp"

PtpConfigSlave.yaml

apiVersion: ptp.openshift.io/v1
kind: PtpConfig
metadata:
  name: ordinary
  namespace: openshift-ptp
  annotations: {}
spec:
  profile:
    - name: "ordinary"
      # The interface name is hardware-specific
      interface: $interface
      ptp4lOpts: "-2 -s"
      phc2sysOpts: "-a -r -n 24"
      ptpSchedulingPolicy: SCHED_FIFO
      ptpSchedulingPriority: 10
      ptpSettings:
        logReduce: "true"
      ptp4lConf: |
        [global]
        #
        # Default Data Set
        #
        twoStepFlag 1
        slaveOnly 1
        priority1 128
        priority2 128
        domainNumber 24
        #utc_offset 37
        clockClass 255
        clockAccuracy 0xFE
        offsetScaledLogVariance 0xFFFF
        free_running 0
        freq_est_interval 1
        dscp_event 0
        dscp_general 0
        dataset_comparison G.8275.x
        G.8275.defaultDS.localPriority 128
        #
        # Port Data Set
        #
        logAnnounceInterval -3
        logSyncInterval -4
        logMinDelayReqInterval -4
        logMinPdelayReqInterval -4
        announceReceiptTimeout 3
        syncReceiptTimeout 0
        delayAsymmetry 0
        fault_reset_interval -4
        neighborPropDelayThresh 20000000
        masterOnly 0
        G.8275.portDS.localPriority 128
        #
        # Run time options
        #
        assume_two_step 0
        logging_level 6
        path_trace_enabled 0
        follow_up_info 0
        hybrid_e2e 0
        inhibit_multicast_service 0
        net_sync_monitor 0
        tc_spanning_tree 0
        tx_timestamp_timeout 50
        unicast_listen 0
        unicast_master_table 0
        unicast_req_duration 3600
        use_syslog 1
        verbose 0
        summary_interval 0
        kernel_leap 1
        check_fup_sync 0
        clock_class_threshold 7
        #
        # Servo Options
        #
        pi_proportional_const 0.0
        pi_integral_const 0.0
        pi_proportional_scale 0.0
        pi_proportional_exponent -0.3
        pi_proportional_norm_max 0.7
        pi_integral_scale 0.0
        pi_integral_exponent 0.4
        pi_integral_norm_max 0.3
        step_threshold 2.0
        first_step_threshold 0.00002
        max_frequency 900000000
        clock_servo pi
        sanity_freq_limit 200000000
        ntpshm_segment 0
        #
        # Transport options
        #
        transportSpecific 0x0
        ptp_dst_mac 01:1B:19:00:00:00
        p2p_dst_mac 01:80:C2:00:00:0E
        udp_ttl 1
        udp6_scope 0x0E
        uds_address /var/run/ptp4l
        #
        # Default interface options
        #
        clock_type OC
        network_transport L2
        delay_mechanism E2E
        time_stamping hardware
        tsproc_mode filter
        delay_filter moving_median
        delay_filter_length 10
        egressLatency 0
        ingressLatency 0
        boundary_clock_jbod 0
        #
        # Clock description
        #
        productDescription ;;
        revisionData ;;
        manufacturerIdentity 00:00:00
        userDescription ;
        timeSource 0xA0
  recommend:
    - profile: "ordinary"
      priority: 4
      match:
        - nodeLabel: "node-role.kubernetes.io/$mcp"

PtpSubscription.yaml

---
apiVersion: operators.coreos.com/v1alpha1
kind: Subscription
metadata:
  name: ptp-operator-subscription
  namespace: openshift-ptp
  annotations: {}
spec:
  channel: "stable"
  name: ptp-operator
  source: redhat-operators-disconnected
  sourceNamespace: openshift-marketplace
  installPlanApproval: Manual
status:
  state: AtLatestKnown

PtpSubscriptionNS.yaml

---
apiVersion: v1
kind: Namespace
metadata:
  name: openshift-ptp
  annotations:
    workload.openshift.io/allowed: management
  labels:
    openshift.io/cluster-monitoring: "true"

PtpSubscriptionOperGroup.yaml

apiVersion: operators.coreos.com/v1
kind: OperatorGroup
metadata:
  name: ptp-operators
  namespace: openshift-ptp
  annotations: {}
spec:
  targetNamespaces:
    - openshift-ptp

AcceleratorsNS.yaml

apiVersion: v1
kind: Namespace
metadata:
  name: vran-acceleration-operators
  annotations: {}

AcceleratorsOperGroup.yaml

apiVersion: operators.coreos.com/v1
kind: OperatorGroup
metadata:
  name: vran-operators
  namespace: vran-acceleration-operators
  annotations: {}
spec:
  targetNamespaces:
    - vran-acceleration-operators

AcceleratorsSubscription.yaml

apiVersion: operators.coreos.com/v1alpha1
kind: Subscription
metadata:
  name: sriov-fec-subscription
  namespace: vran-acceleration-operators
  annotations: {}
spec:
  channel: stable
  name: sriov-fec
  source: certified-operators
  sourceNamespace: openshift-marketplace
  installPlanApproval: Manual
status:
  state: AtLatestKnown

SriovFecClusterConfig.yaml

apiVersion: sriovfec.intel.com/v2
kind: SriovFecClusterConfig
metadata:
  name: config
  namespace: vran-acceleration-operators
  annotations: {}
spec:
  drainSkip: $drainSkip # true if SNO, false by default
  priority: 1
  nodeSelector:
    node-role.kubernetes.io/master: ""
  acceleratorSelector:
    pciAddress: $pciAddress
  physicalFunction:
    pfDriver: "vfio-pci"
    vfDriver: "vfio-pci"
    vfAmount: 16
    bbDevConfig: $bbDevConfig
#Recommended configuration for Intel ACC100 (Mount Bryce) FPGA here: https://github.com/smart-edge-open/openshift-operator/blob/main/spec/openshift-sriov-fec-operator.md#sample-cr-for-wireless-fec-acc100
#Recommended configuration for Intel N3000 FPGA here: https://github.com/smart-edge-open/openshift-operator/blob/main/spec/openshift-sriov-fec-operator.md#sample-cr-for-wireless-fec-n3000

SriovNetwork.yaml

apiVersion: sriovnetwork.openshift.io/v1
kind: SriovNetwork
metadata:
  name: ""
  namespace: openshift-sriov-network-operator
  annotations: {}
spec:
  #  resourceName: ""
  networkNamespace: openshift-sriov-network-operator
#  vlan: ""
#  spoofChk: ""
#  ipam: ""
#  linkState: ""
#  maxTxRate: ""
#  minTxRate: ""
#  vlanQoS: ""
#  trust: ""
#  capabilities: ""

SriovNetworkNodePolicy.yaml

apiVersion: sriovnetwork.openshift.io/v1
kind: SriovNetworkNodePolicy
metadata:
  name: $name
  namespace: openshift-sriov-network-operator
  annotations: {}
spec:
  # The attributes for Mellanox/Intel based NICs as below.
  #     deviceType: netdevice/vfio-pci
  #     isRdma: true/false
  deviceType: $deviceType
  isRdma: $isRdma
  nicSelector:
    # The exact physical function name must match the hardware used
    pfNames: [$pfNames]
  nodeSelector:
    node-role.kubernetes.io/$mcp: ""
  numVfs: $numVfs
  priority: $priority
  resourceName: $resourceName

SriovOperatorConfig.yaml

apiVersion: sriovnetwork.openshift.io/v1
kind: SriovOperatorConfig
metadata:
  name: default
  namespace: openshift-sriov-network-operator
  annotations: {}
spec:
  configDaemonNodeSelector:
    "node-role.kubernetes.io/$mcp": ""
  # Injector and OperatorWebhook pods can be disabled (set to "false") below
  # to reduce the number of management pods. It is recommended to start with the
  # webhook and injector pods enabled, and only disable them after verifying the
  # correctness of user manifests.
  #   If the injector is disabled, containers using sr-iov resources must explicitly assign
  #   them in the  "requests"/"limits" section of the container spec, for example:
  #    containers:
  #    - name: my-sriov-workload-container
  #      resources:
  #        limits:
  #          openshift.io/<resource_name>:  "1"
  #        requests:
  #          openshift.io/<resource_name>:  "1"
  enableInjector: true
  enableOperatorWebhook: true
  logLevel: 0

SriovSubscription.yaml

apiVersion: operators.coreos.com/v1alpha1
kind: Subscription
metadata:
  name: sriov-network-operator-subscription
  namespace: openshift-sriov-network-operator
  annotations: {}
spec:
  channel: "stable"
  name: sriov-network-operator
  source: redhat-operators-disconnected
  sourceNamespace: openshift-marketplace
  installPlanApproval: Manual
status:
  state: AtLatestKnown

SriovSubscriptionNS.yaml

apiVersion: v1
kind: Namespace
metadata:
  name: openshift-sriov-network-operator
  annotations:
    workload.openshift.io/allowed: management

SriovSubscriptionOperGroup.yaml

apiVersion: operators.coreos.com/v1
kind: OperatorGroup
metadata:
  name: sriov-network-operators
  namespace: openshift-sriov-network-operator
  annotations: {}
spec:
  targetNamespaces:
    - openshift-sriov-network-operator

3.2.4.4.2. Cluster tuning reference YAML

example-sno.yaml

# example-node1-bmh-secret & assisted-deployment-pull-secret need to be created under same namespace example-sno
---
apiVersion: ran.openshift.io/v1
kind: SiteConfig
metadata:
  name: "example-sno"
  namespace: "example-sno"
spec:
  baseDomain: "example.com"
  pullSecretRef:
    name: "assisted-deployment-pull-secret"
  clusterImageSetNameRef: "openshift-4.10"
  sshPublicKey: "ssh-rsa AAAA..."
  clusters:
  - clusterName: "example-sno"
    networkType: "OVNKubernetes"
    # installConfigOverrides is a generic way of passing install-config
    # parameters through the siteConfig.  The 'capabilities' field configures
    # the composable openshift feature.  In this 'capabilities' setting, we
    # remove all but the marketplace component from the optional set of
    # components.
    # Notes:
    # - OperatorLifecycleManager is needed for 4.15 and later
    # - NodeTuning is needed for 4.13 and later, not for 4.12 and earlier
    installConfigOverrides: |
      {
        "capabilities": {
          "baselineCapabilitySet": "None",
          "additionalEnabledCapabilities": [
            "NodeTuning",
            "OperatorLifecycleManager"
          ]
        }
      }
    # It is strongly recommended to include crun manifests as part of the additional install-time manifests for 4.13+.
    # The crun manifests can be obtained from source-crs/optional-extra-manifest/ and added to the git repo ie.sno-extra-manifest.
    # extraManifestPath: sno-extra-manifest
    clusterLabels:
      # These example cluster labels correspond to the bindingRules in the PolicyGenTemplate examples
      du-profile: "latest"
      # These example cluster labels correspond to the bindingRules in the PolicyGenTemplate examples in ../policygentemplates:
      # ../policygentemplates/common-ranGen.yaml will apply to all clusters with 'common: true'
      common: true
      # ../policygentemplates/group-du-sno-ranGen.yaml will apply to all clusters with 'group-du-sno: ""'
      group-du-sno: ""
      # ../policygentemplates/example-sno-site.yaml will apply to all clusters with 'sites: "example-sno"'
      # Normally this should match or contain the cluster name so it only applies to a single cluster
      sites : "example-sno"
    clusterNetwork:
      - cidr: 1001:1::/48
        hostPrefix: 64
    machineNetwork:
      - cidr: 1111:2222:3333:4444::/64
    serviceNetwork:
      - 1001:2::/112
    additionalNTPSources:
      - 1111:2222:3333:4444::2
    # Initiates the cluster for workload partitioning. Setting specific reserved/isolated CPUSets is done via PolicyTemplate
    # please see Workload Partitioning Feature for a complete guide.
    cpuPartitioningMode: AllNodes
    # Optionally; This can be used to override the KlusterletAddonConfig that is created for this cluster:
    #crTemplates:
    #  KlusterletAddonConfig: "KlusterletAddonConfigOverride.yaml"
    nodes:
      - hostName: "example-node1.example.com"
        role: "master"
        # Optionally; This can be used to configure desired BIOS setting on a host:
        #biosConfigRef:
        #  filePath: "example-hw.profile"
        bmcAddress: "idrac-virtualmedia+https://[1111:2222:3333:4444::bbbb:1]/redfish/v1/Systems/System.Embedded.1"
        bmcCredentialsName:
          name: "example-node1-bmh-secret"
        bootMACAddress: "AA:BB:CC:DD:EE:11"
        # Use UEFISecureBoot to enable secure boot
        bootMode: "UEFI"
        rootDeviceHints:
          deviceName: "/dev/disk/by-path/pci-0000:01:00.0-scsi-0:2:0:0"
        # disk partition at `/var/lib/containers` with ignitionConfigOverride. Some values must be updated. See DiskPartitionContainer.md for more details
        ignitionConfigOverride: |
           {
            "ignition": {
              "version": "3.2.0"
            },
            "storage": {
              "disks": [
                {
                  "device": "/dev/disk/by-path/pci-0000:01:00.0-scsi-0:2:0:0",
                  "partitions": [
                    {
                     "label": "var-lib-containers",
                     "sizeMiB": 0,
                     "startMiB": 250000
                  }
              ],
              "wipeTable": false
             }
           ],
            "filesystems": [
              {
               "device": "/dev/disk/by-partlabel/var-lib-containers",
               "format": "xfs",
               "mountOptions": [
                 "defaults",
                 "prjquota"
                ],
                "path": "/var/lib/containers",
                "wipeFilesystem": true
               }
             ]
           },
           "systemd": {
             "units": [
               {
                "contents": "# Generated by Butane\n[Unit]\nRequires=systemd-fsck@dev-disk-by\\x2dpartlabel-var\\x2dlib\\x2dcontainers.service\nAfter=systemd-fsck@dev-disk-by\\x2dpartlabel-var\\x2dlib\\x2dcontainers.service\n\n[Mount]\nWhere=/var/lib/containers\nWhat=/dev/disk/by-partlabel/var-lib-containers\nType=xfs\nOptions=defaults,prjquota\n\n[Install]\nRequiredBy=local-fs.target",
                "enabled": true,
                "name": "var-lib-containers.mount"
               }
              ]
            }
           }
        nodeNetwork:
          interfaces:
            - name: eno1
              macAddress: "AA:BB:CC:DD:EE:11"
          config:
            interfaces:
              - name: eno1
                type: ethernet
                state: up
                ipv4:
                  enabled: false
                ipv6:
                  enabled: true
                  address:
                  # For SNO sites with static IP addresses, the node-specific,
                  # API and Ingress IPs should all be the same and configured on
                  # the interface
                  - ip: 1111:2222:3333:4444::aaaa:1
                    prefix-length: 64
            dns-resolver:
              config:
                search:
                - example.com
                server:
                - 1111:2222:3333:4444::2
            routes:
              config:
              - destination: ::/0
                next-hop-interface: eno1
                next-hop-address: 1111:2222:3333:4444::1
                table-id: 254

DisableSnoNetworkDiag.yaml

apiVersion: operator.openshift.io/v1
kind: Network
metadata:
  name: cluster
  annotations: {}
spec:
  disableNetworkDiagnostics: true

ReduceMonitoringFootprint.yaml

apiVersion: v1
kind: ConfigMap
metadata:
  name: cluster-monitoring-config
  namespace: openshift-monitoring
  annotations: {}
data:
  config.yaml: |
    grafana:
      enabled: false
    alertmanagerMain:
      enabled: false
    telemeterClient:
      enabled: false
    prometheusK8s:
       retention: 24h

DefaultCatsrc.yaml

apiVersion: operators.coreos.com/v1alpha1
kind: CatalogSource
metadata:
  name: default-cat-source
  namespace: openshift-marketplace
  annotations:
    target.workload.openshift.io/management: '{"effect": "PreferredDuringScheduling"}'
spec:
  displayName: default-cat-source
  image: $imageUrl
  publisher: Red Hat
  sourceType: grpc
  updateStrategy:
    registryPoll:
      interval: 1h
status:
  connectionState:
    lastObservedState: READY

DisconnectedICSP.yaml

apiVersion: operator.openshift.io/v1alpha1
kind: ImageContentSourcePolicy
metadata:
  name: disconnected-internal-icsp
  annotations: {}
spec:
  repositoryDigestMirrors:
    - $mirrors

OperatorHub.yaml

apiVersion: config.openshift.io/v1
kind: OperatorHub
metadata:
  name: cluster
  annotations: {}
spec:
  disableAllDefaultSources: true

3.2.4.4.3. Machine configuration reference YAML

enable-crun-master.yaml

apiVersion: machineconfiguration.openshift.io/v1
kind: ContainerRuntimeConfig
metadata:
  name: enable-crun-master
spec:
  machineConfigPoolSelector:
    matchLabels:
      pools.operator.machineconfiguration.openshift.io/master: ""
  containerRuntimeConfig:
    defaultRuntime: crun

enable-crun-worker.yaml

apiVersion: machineconfiguration.openshift.io/v1
kind: ContainerRuntimeConfig
metadata:
  name: enable-crun-worker
spec:
  machineConfigPoolSelector:
    matchLabels:
      pools.operator.machineconfiguration.openshift.io/worker: ""
  containerRuntimeConfig:
    defaultRuntime: crun

99-crio-disable-wipe-master.yaml

apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: master
  name: 99-crio-disable-wipe-master
spec:
  config:
    ignition:
      version: 3.2.0
    storage:
      files:
        - contents:
            source: data:text/plain;charset=utf-8;base64,W2NyaW9dCmNsZWFuX3NodXRkb3duX2ZpbGUgPSAiIgo=
          mode: 420
          path: /etc/crio/crio.conf.d/99-crio-disable-wipe.toml

99-crio-disable-wipe-worker.yaml

apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: worker
  name: 99-crio-disable-wipe-worker
spec:
  config:
    ignition:
      version: 3.2.0
    storage:
      files:
        - contents:
            source: data:text/plain;charset=utf-8;base64,W2NyaW9dCmNsZWFuX3NodXRkb3duX2ZpbGUgPSAiIgo=
          mode: 420
          path: /etc/crio/crio.conf.d/99-crio-disable-wipe.toml

05-kdump-config-master.yaml

apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: master
  name: 05-kdump-config-master
spec:
  config:
    ignition:
      version: 3.2.0
    systemd:
      units:
        - enabled: true
          name: kdump-remove-ice-module.service
          contents: |
            [Unit]
            Description=Remove ice module when doing kdump
            Before=kdump.service
            [Service]
            Type=oneshot
            RemainAfterExit=true
            ExecStart=/usr/local/bin/kdump-remove-ice-module.sh
            [Install]
            WantedBy=multi-user.target
    storage:
      files:
        - contents:
            source: data:text/plain;charset=utf-8;base64,IyEvdXNyL2Jpbi9lbnYgYmFzaAoKIyBUaGlzIHNjcmlwdCByZW1vdmVzIHRoZSBpY2UgbW9kdWxlIGZyb20ga2R1bXAgdG8gcHJldmVudCBrZHVtcCBmYWlsdXJlcyBvbiBjZXJ0YWluIHNlcnZlcnMuCiMgVGhpcyBpcyBhIHRlbXBvcmFyeSB3b3JrYXJvdW5kIGZvciBSSEVMUExBTi0xMzgyMzYgYW5kIGNhbiBiZSByZW1vdmVkIHdoZW4gdGhhdCBpc3N1ZSBpcwojIGZpeGVkLgoKc2V0IC14CgpTRUQ9Ii91c3IvYmluL3NlZCIKR1JFUD0iL3Vzci9iaW4vZ3JlcCIKCiMgb3ZlcnJpZGUgZm9yIHRlc3RpbmcgcHVycG9zZXMKS0RVTVBfQ09ORj0iJHsxOi0vZXRjL3N5c2NvbmZpZy9rZHVtcH0iClJFTU9WRV9JQ0VfU1RSPSJtb2R1bGVfYmxhY2tsaXN0PWljZSIKCiMgZXhpdCBpZiBmaWxlIGRvZXNuJ3QgZXhpc3QKWyAhIC1mICR7S0RVTVBfQ09ORn0gXSAmJiBleGl0IDAKCiMgZXhpdCBpZiBmaWxlIGFscmVhZHkgdXBkYXRlZAoke0dSRVB9IC1GcSAke1JFTU9WRV9JQ0VfU1RSfSAke0tEVU1QX0NPTkZ9ICYmIGV4aXQgMAoKIyBUYXJnZXQgbGluZSBsb29rcyBzb21ldGhpbmcgbGlrZSB0aGlzOgojIEtEVU1QX0NPTU1BTkRMSU5FX0FQUEVORD0iaXJxcG9sbCBucl9jcHVzPTEgLi4uIGhlc3RfZGlzYWJsZSIKIyBVc2Ugc2VkIHRvIG1hdGNoIGV2ZXJ5dGhpbmcgYmV0d2VlbiB0aGUgcXVvdGVzIGFuZCBhcHBlbmQgdGhlIFJFTU9WRV9JQ0VfU1RSIHRvIGl0CiR7U0VEfSAtaSAncy9eS0RVTVBfQ09NTUFORExJTkVfQVBQRU5EPSJbXiJdKi8mICcke1JFTU9WRV9JQ0VfU1RSfScvJyAke0tEVU1QX0NPTkZ9IHx8IGV4aXQgMAo=
          mode: 448
          path: /usr/local/bin/kdump-remove-ice-module.sh

05-kdump-config-worker.yaml

apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: worker
  name: 05-kdump-config-worker
spec:
  config:
    ignition:
      version: 3.2.0
    systemd:
      units:
        - enabled: true
          name: kdump-remove-ice-module.service
          contents: |
            [Unit]
            Description=Remove ice module when doing kdump
            Before=kdump.service
            [Service]
            Type=oneshot
            RemainAfterExit=true
            ExecStart=/usr/local/bin/kdump-remove-ice-module.sh
            [Install]
            WantedBy=multi-user.target
    storage:
      files:
        - contents:
            source: data:text/plain;charset=utf-8;base64,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
          mode: 448
          path: /usr/local/bin/kdump-remove-ice-module.sh

06-kdump-master.yaml

apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: master
  name: 06-kdump-enable-master
spec:
  config:
    ignition:
      version: 3.2.0
    systemd:
      units:
        - enabled: true
          name: kdump.service
  kernelArguments:
    - crashkernel=512M

06-kdump-worker.yaml

apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: worker
  name: 06-kdump-enable-worker
spec:
  config:
    ignition:
      version: 3.2.0
    systemd:
      units:
        - enabled: true
          name: kdump.service
  kernelArguments:
    - crashkernel=512M

01-container-mount-ns-and-kubelet-conf-master.yaml

apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: master
  name: container-mount-namespace-and-kubelet-conf-master
spec:
  config:
    ignition:
      version: 3.2.0
    storage:
      files:
        - contents:
            source: data:text/plain;charset=utf-8;base64,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
          mode: 493
          path: /usr/local/bin/extractExecStart
        - contents:
            source: data:text/plain;charset=utf-8;base64,IyEvYmluL2Jhc2gKbnNlbnRlciAtLW1vdW50PS9ydW4vY29udGFpbmVyLW1vdW50LW5hbWVzcGFjZS9tbnQgIiRAIgo=
          mode: 493
          path: /usr/local/bin/nsenterCmns
    systemd:
      units:
        - contents: |
            [Unit]
            Description=Manages a mount namespace that both kubelet and crio can use to share their container-specific mounts

            [Service]
            Type=oneshot
            RemainAfterExit=yes
            RuntimeDirectory=container-mount-namespace
            Environment=RUNTIME_DIRECTORY=%t/container-mount-namespace
            Environment=BIND_POINT=%t/container-mount-namespace/mnt
            ExecStartPre=bash -c "findmnt ${RUNTIME_DIRECTORY} || mount --make-unbindable --bind ${RUNTIME_DIRECTORY} ${RUNTIME_DIRECTORY}"
            ExecStartPre=touch ${BIND_POINT}
            ExecStart=unshare --mount=${BIND_POINT} --propagation slave mount --make-rshared /
            ExecStop=umount -R ${RUNTIME_DIRECTORY}
          name: container-mount-namespace.service
        - dropins:
            - contents: |
                [Unit]
                Wants=container-mount-namespace.service
                After=container-mount-namespace.service

                [Service]
                ExecStartPre=/usr/local/bin/extractExecStart %n /%t/%N-execstart.env ORIG_EXECSTART
                EnvironmentFile=-/%t/%N-execstart.env
                ExecStart=
                ExecStart=bash -c "nsenter --mount=%t/container-mount-namespace/mnt \
                    ${ORIG_EXECSTART}"
              name: 90-container-mount-namespace.conf
          name: crio.service
        - dropins:
            - contents: |
                [Unit]
                Wants=container-mount-namespace.service
                After=container-mount-namespace.service

                [Service]
                ExecStartPre=/usr/local/bin/extractExecStart %n /%t/%N-execstart.env ORIG_EXECSTART
                EnvironmentFile=-/%t/%N-execstart.env
                ExecStart=
                ExecStart=bash -c "nsenter --mount=%t/container-mount-namespace/mnt \
                    ${ORIG_EXECSTART} --housekeeping-interval=30s"
              name: 90-container-mount-namespace.conf
            - contents: |
                [Service]
                Environment="OPENSHIFT_MAX_HOUSEKEEPING_INTERVAL_DURATION=60s"
                Environment="OPENSHIFT_EVICTION_MONITORING_PERIOD_DURATION=30s"
              name: 30-kubelet-interval-tuning.conf
          name: kubelet.service

01-container-mount-ns-and-kubelet-conf-worker.yaml

apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: worker
  name: container-mount-namespace-and-kubelet-conf-worker
spec:
  config:
    ignition:
      version: 3.2.0
    storage:
      files:
        - contents:
            source: data:text/plain;charset=utf-8;base64,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
          mode: 493
          path: /usr/local/bin/extractExecStart
        - contents:
            source: data:text/plain;charset=utf-8;base64,IyEvYmluL2Jhc2gKbnNlbnRlciAtLW1vdW50PS9ydW4vY29udGFpbmVyLW1vdW50LW5hbWVzcGFjZS9tbnQgIiRAIgo=
          mode: 493
          path: /usr/local/bin/nsenterCmns
    systemd:
      units:
        - contents: |
            [Unit]
            Description=Manages a mount namespace that both kubelet and crio can use to share their container-specific mounts

            [Service]
            Type=oneshot
            RemainAfterExit=yes
            RuntimeDirectory=container-mount-namespace
            Environment=RUNTIME_DIRECTORY=%t/container-mount-namespace
            Environment=BIND_POINT=%t/container-mount-namespace/mnt
            ExecStartPre=bash -c "findmnt ${RUNTIME_DIRECTORY} || mount --make-unbindable --bind ${RUNTIME_DIRECTORY} ${RUNTIME_DIRECTORY}"
            ExecStartPre=touch ${BIND_POINT}
            ExecStart=unshare --mount=${BIND_POINT} --propagation slave mount --make-rshared /
            ExecStop=umount -R ${RUNTIME_DIRECTORY}
          name: container-mount-namespace.service
        - dropins:
            - contents: |
                [Unit]
                Wants=container-mount-namespace.service
                After=container-mount-namespace.service

                [Service]
                ExecStartPre=/usr/local/bin/extractExecStart %n /%t/%N-execstart.env ORIG_EXECSTART
                EnvironmentFile=-/%t/%N-execstart.env
                ExecStart=
                ExecStart=bash -c "nsenter --mount=%t/container-mount-namespace/mnt \
                    ${ORIG_EXECSTART}"
              name: 90-container-mount-namespace.conf
          name: crio.service
        - dropins:
            - contents: |
                [Unit]
                Wants=container-mount-namespace.service
                After=container-mount-namespace.service

                [Service]
                ExecStartPre=/usr/local/bin/extractExecStart %n /%t/%N-execstart.env ORIG_EXECSTART
                EnvironmentFile=-/%t/%N-execstart.env
                ExecStart=
                ExecStart=bash -c "nsenter --mount=%t/container-mount-namespace/mnt \
                    ${ORIG_EXECSTART} --housekeeping-interval=30s"
              name: 90-container-mount-namespace.conf
            - contents: |
                [Service]
                Environment="OPENSHIFT_MAX_HOUSEKEEPING_INTERVAL_DURATION=60s"
                Environment="OPENSHIFT_EVICTION_MONITORING_PERIOD_DURATION=30s"
              name: 30-kubelet-interval-tuning.conf
          name: kubelet.service

99-sync-time-once-master.yaml

apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: master
  name: 99-sync-time-once-master
spec:
  config:
    ignition:
      version: 3.2.0
    systemd:
      units:
        - contents: |
            [Unit]
            Description=Sync time once
            After=network.service
            [Service]
            Type=oneshot
            TimeoutStartSec=300
            ExecStart=/usr/sbin/chronyd -n -f /etc/chrony.conf -q
            RemainAfterExit=yes
            [Install]
            WantedBy=multi-user.target
          enabled: true
          name: sync-time-once.service

99-sync-time-once-worker.yaml

apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: worker
  name: 99-sync-time-once-worker
spec:
  config:
    ignition:
      version: 3.2.0
    systemd:
      units:
        - contents: |
            [Unit]
            Description=Sync time once
            After=network.service
            [Service]
            Type=oneshot
            TimeoutStartSec=300
            ExecStart=/usr/sbin/chronyd -n -f /etc/chrony.conf -q
            RemainAfterExit=yes
            [Install]
            WantedBy=multi-user.target
          enabled: true
          name: sync-time-once.service

03-sctp-machine-config-master.yaml

apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: master
  name: load-sctp-module-master
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
        - contents:
            source: data:,
            verification: {}
          filesystem: root
          mode: 420
          path: /etc/modprobe.d/sctp-blacklist.conf
        - contents:
            source: data:text/plain;charset=utf-8,sctp
          filesystem: root
          mode: 420
          path: /etc/modules-load.d/sctp-load.conf

03-sctp-machine-config-worker.yaml

apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: worker
  name: load-sctp-module-worker
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
        - contents:
            source: data:,
            verification: {}
          filesystem: root
          mode: 420
          path: /etc/modprobe.d/sctp-blacklist.conf
        - contents:
            source: data:text/plain;charset=utf-8,sctp
          filesystem: root
          mode: 420
          path: /etc/modules-load.d/sctp-load.conf

07-sriov-related-kernel-args-master.yaml

apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: master
  name: 07-sriov-related-kernel-args-master
spec:
  config:
    ignition:
      version: 3.2.0
  kernelArguments:
    - intel_iommu=on
    - iommu=pt

3.2.5. Telco RAN DU reference configuration software specifications

The following information describes the telco RAN DU reference design specification (RDS) validated software versions.

3.2.5.1. Telco RAN DU 4.14 validated software components

The Red Hat telco RAN DU 4.14 solution has been validated using the following Red Hat software products for OpenShift Container Platform managed clusters and hub clusters.

Table 3.8. Telco RAN DU managed cluster validated software components
Component	Software version
Managed cluster version	4.14
Cluster Logging Operator	5.7
Local Storage Operator	4.14
PTP Operator	4.14
SRIOV Operator	4.14
Node Tuning Operator	4.14
Logging Operator	4.14
SRIOV-FEC Operator	2.7

Table 3.9. Hub cluster validated software components
Component	Software version
Hub cluster version	4.14
GitOps ZTP plugin	4.14
Red Hat Advanced Cluster Management (RHACM)	2.9, 2.10
Red Hat OpenShift GitOps	1.9, 1.10
Topology Aware Lifecycle Manager (TALM)	4.14

3.3. Telco core reference design specification

3.3.1. Telco core 4.14 reference design overview

The telco core reference design specification (RDS) configures a OpenShift Container Platform cluster running on commodity hardware to host telco core workloads.

3.3.1.1. OpenShift Container Platform 4.14 features for telco core

The following features that are included in OpenShift Container Platform 4.14 and are leveraged by the telco core reference design specification (RDS) have been added or updated.

Table 3.10. New features for telco core in OpenShift Container Platform 4.14
Feature	Description
Support for running rootless Data Plane Development Kit (DPDK) workloads with kernel access by using the TAP CNI plugin	DPDK applications that inject traffic into the kernel can run in non-privileged pods with the help of the TAP CNI plugin. Using the TAP CNI to run a rootless DPDK workload with kernel access
Dynamic use of non-reserved CPUs for OVS	With this release, the Open vSwitch (OVS) networking stack can dynamically use non-reserved CPUs. The dynamic use of non-reserved CPUs occurs by default in performance-tuned clusters with a CPU manager policy set to `static`. The dynamic use of available, non-reserved CPUs maximizes compute resources for OVS and minimizes network latency for workloads during periods of high demand. OVS cannot use isolated CPUs assigned to containers in `Guaranteed` QoS pods. This separation avoids disruption to critical application workloads.
Enabling more control over the C-states for each pod	The `PerformanceProfile` supports `perPodPowerManagement` which provides more control over the C-states for pods. Now, instead of disabling C-states completely, you can specify a maximum latency in microseconds for C-states. You configure this option in the `cpu-c-states.crio.io` annotation, which helps to optimize power savings for high-priority applications by enabling some of the shallower C-states instead of disabling them completely. Optional: Power saving configurations
Exclude SR-IOV network topology for NUMA-aware scheduling	You can exclude advertising Non-Uniform Memory Access (NUMA) nodes for the SR-IOV network to the Topology Manager. By not advertising NUMA nodes for the SR-IOV network, you can permit more flexible SR-IOV network deployments during NUMA-aware pod scheduling. For example, in some scenarios, you want flexibility for how a pod is deployed. By not providing a NUMA node hint to the Topology Manager for the pod’s SR-IOV network resource, the Topology Manager can deploy the SR-IOV network resource and the pod CPU and memory resources to different NUMA nodes. In previous OpenShift Container Platform releases, the Topology Manager attempted to place all resources on the same NUMA node. Exclude the SR-IOV network topology for NUMA-aware scheduling
Egress service resource to manage egress traffic for pods behind a load balancer (Technology Preview)	With this update, you can use an `EgressService` custom resource (CR) to manage egress traffic for pods behind a load balancer service. You can use the `EgressService` CR to manage egress traffic in the following ways: Assign the load balancer service’s IP address as the source IP address of egress traffic for pods behind the load balancer service. Configure the egress traffic for pods behind a load balancer to a different network than the default node network. Configuring an egress service

3.3.2. Telco core 4.14 use model overview

The Telco core reference design specification (RDS) describes a platform that supports large-scale telco applications including control plane functions such as signaling and aggregation. It also includes some centralized data plane functions, for example, user plane functions (UPF). These functions generally require scalability, complex networking support, resilient software-defined storage, and support performance requirements that are less stringent and constrained than far-edge deployments like RAN.

Telco core use model architecture

Use model architecture

The networking prerequisites for telco core functions are diverse and encompass an array of networking attributes and performance benchmarks. IPv6 is mandatory, with dual-stack configurations being prevalent. Certain functions demand maximum throughput and transaction rates, necessitating user plane networking support such as DPDK. Other functions adhere to conventional cloud-native patterns and can use solutions such as OVN-K, kernel networking, and load balancing.

Telco core clusters are configured as standard three control plane clusters with worker nodes configured with the stock non real-time (RT) kernel. To support workloads with varying networking and performance requirements, worker nodes are segmented using MachineConfigPool CRs. For example, this is done to separate non-user data plane nodes from high-throughput nodes. To support the required telco operational features, the clusters have a standard set of Operator Lifecycle Manager (OLM) Day 2 Operators installed.

3.3.2.1. Common baseline model

The following configurations and use model description are applicable to all telco core use cases.

Cluster

The cluster conforms to these requirements:

High-availability (3+ supervisor nodes) control plane
Non-schedulable supervisor nodes

Storage

Core use cases require persistent storage as provided by external OpenShift Data Foundation. For more information, see the "Storage" subsection in "Reference core design components".

Networking

Telco core clusters networking conforms to these requirements:

Dual stack IPv4/IPv6
Fully disconnected: Clusters do not have access to public networking at any point in their lifecycle.
Multiple networks: Segmented networking provides isolation between OAM, signaling, and storage traffic.
Cluster network type: OVN-Kubernetes is required for IPv6 support.

Core clusters have multiple layers of networking supported by underlying RHCOS, SR-IOV Operator, Load Balancer, and other components detailed in the following "Networking" section. At a high level these layers include:

Cluster networking: The cluster network configuration is defined and applied through the installation configuration. Updates to the configuration can be done at day-2 through the NMState Operator. Initial configuration can be used to establish:
- Host interface configuration
- A/A Bonding (Link Aggregation Control Protocol (LACP))
Secondary or additional networks: OpenShift CNI is configured through the Network additionalNetworks or NetworkAttachmentDefinition CRs.
- MACVLAN
Application Workload: User plane networking is running in cloud-native network functions (CNFs).

Service Mesh

Use of Service Mesh by telco CNFs is very common. It is expected that all core clusters will include a Service Mesh implementation. Service Mesh implementation and configuration is outside the scope of this specification.

3.3.2.1.1. Engineering Considerations common use model

The following engineering considerations are relevant for the common use model.

Worker nodes

Worker nodes run on Intel 3rd Generation Xeon (IceLake) processors or newer. Alternatively, if using Skylake or earlier processors, the mitigations for silicon security vulnerabilities such as Spectre must be disabled; failure to do so may result in a significant 40 percent decrease in transaction performance.
IRQ Balancing is enabled on worker nodes. The PerformanceProfile sets globallyDisableIrqLoadBalancing: false. Guaranteed QoS Pods are annotated to ensure isolation as described in "CPU partitioning and performance tuning" subsection in "Reference core design components" section.

All nodes

Hyper-Threading is enabled on all nodes
CPU architecture is x86_64 only
Nodes are running the stock (non-RT) kernel
Nodes are not configured for workload partitioning

The balance of node configuration between power management and maximum performance varies between MachineConfigPools in the cluster. This configuration is consistent for all nodes within a MachineConfigPool.

CPU partitioning: CPU partitioning is configured using the PerformanceProfile and applied on a per MachineConfigPool basis. See the "CPU partitioning and performance tuning" subsection in "Reference core design components".

3.3.2.1.2. Application workloads

Application workloads running on core clusters might include a mix of high-performance networking CNFs and traditional best-effort or burstable pod workloads.

Guaranteed QoS scheduling is available to pods that require exclusive or dedicated use of CPUs due to performance or security requirements. Typically pods hosting high-performance and low-latency-sensitive Cloud Native Functions (CNFs) utilizing user plane networking with DPDK necessitate the exclusive utilization of entire CPUs. This is accomplished through node tuning and guaranteed Quality of Service (QoS) scheduling. For pods that require exclusive use of CPUs, be aware of the potential implications of hyperthreaded systems and configure them to request multiples of 2 CPUs when the entire core (2 hyperthreads) must be allocated to the pod.

Pods running network functions that do not require the high throughput and low latency networking are typically scheduled with best-effort or burstable QoS and do not require dedicated or isolated CPU cores.

Description of limits

CNF applications should conform to the latest version of the Red Hat Best Practices for Kubernetes guide.
For a mix of best-effort and burstable QoS pods.
- Guaranteed QoS pods might be used but require correct configuration of reserved and isolated CPUs in the PerformanceProfile.
- Guaranteed QoS Pods must include annotations for fully isolating CPUs.
- Best effort and burstable pods are not guaranteed exclusive use of a CPU. Workloads might be preempted by other workloads, operating system daemons, or kernel tasks.
Exec probes should be avoided unless there is no viable alternative.
- Do not use exec probes if a CNF is using CPU pinning.
- Other probe implementations, for example httpGet/tcpSocket, should be used.

Note

Startup probes require minimal resources during steady-state operation. The limitation on exec probes applies primarily to liveness and readiness probes.

Signaling workload

Signaling workloads typically use SCTP, REST, gRPC, or similar TCP or UDP protocols.
The transactions per second (TPS) is in the order of hundreds of thousands using secondary CNI (multus) configured as MACVLAN or SR-IOV.
Signaling workloads run in pods with either guaranteed or burstable QoS.

3.3.3. Telco core reference design components

The following sections describe the various OpenShift Container Platform components and configurations that you use to configure and deploy clusters to run telco core workloads.

3.3.3.1. CPU partitioning and performance tuning

New in this release

Open vSwitch (OVS) is removed from CPU partitioning. OVS manages its cpuset dynamically to automatically adapt to network traffic needs. Users no longer need to reserve additional CPUs for handling high network throughput on the primary container network interface (CNI). There is no impact on the configuration needed to benefit from this change.

Description

CPU partitioning allows for the separation of sensitive workloads from generic purposes, auxiliary processes, interrupts, and driver work queues to achieve improved performance and latency. The CPUs allocated to those auxiliary processes are referred to as reserved in the following sections. In hyperthreaded systems, a CPU is one hyperthread.

For more information, see Restricting CPUs for infra and application containers.

Configure system level performance. For recommended settings, see Configuring host firmware for low latency and high performance.

Limits and requirements

The operating system needs a certain amount of CPU to perform all the support tasks including kernel networking.
- A system with just user plane networking applications (DPDK) needs at least one Core (2 hyperthreads when enabled) reserved for the operating system and the infrastructure components.
A system with Hyper-Threading enabled must always put all core sibling threads to the same pool of CPUs.
The set of reserved and isolated cores must include all CPU cores.
Core 0 of each NUMA node must be included in the reserved CPU set.
Isolated cores might be impacted by interrupts. The following annotations must be attached to the pod if guaranteed QoS pods require full use of the CPU:
```
cpu-load-balancing.crio.io: "disable"
cpu-quota.crio.io: "disable"
irq-load-balancing.crio.io: "disable"
```
When per-pod power management is enabled with PerformanceProfile.workloadHints.perPodPowerManagement the following annotations must also be attached to the pod if guaranteed QoS pods require full use of the CPU:
```
cpu-c-states.crio.io: "disable"
cpu-freq-governor.crio.io: "performance"
```

Engineering considerations

The minimum reserved capacity (systemReserved) required can be found by following the guidance in "Which amount of CPU and memory are recommended to reserve for the system in OCP 4 nodes?"
The actual required reserved CPU capacity depends on the cluster configuration and workload attributes.
This reserved CPU value must be rounded up to a full core (2 hyper-thread) alignment.
Changes to the CPU partitioning will drain and reboot the nodes in the MCP.
The reserved CPUs reduce the pod density, as the reserved CPUs are removed from the allocatable capacity of the OpenShift node.
The real-time workload hint should be enabled if the workload is real-time capable.
Hardware without Interrupt Request (IRQ) affinity support will impact isolated CPUs. To ensure that pods with guaranteed CPU QoS have full use of allocated CPU, all hardware in the server must support IRQ affinity.

Additional resources

Tuning nodes for low latency with the performance profile
Configuring host firmware for low latency and high performance

3.3.3.2. Service Mesh

Description: Telco core CNFs typically require a service mesh implementation. The specific features and performance required are dependent on the application. The selection of service mesh implementation and configuration is outside the scope of this documentation. The impact of service mesh on cluster resource utilization and performance, including additional latency introduced into pod networking, must be accounted for in the overall solution engineering.

Additional resources

About OpenShift Service Mesh

3.3.3.3. Networking

OpenShift Container Platform networking is an ecosystem of features, plugins, and advanced networking capabilities that extend Kubernetes networking with the advanced networking-related features that your cluster needs to manage its network traffic for one or multiple hybrid clusters.

Additional resources

Understanding networking

3.3.3.3.1. Cluster Network Operator (CNO)

New in this release

Not applicable.

Description

The CNO deploys and manages the cluster network components including the default OVN-Kubernetes network plugin during OpenShift Container Platform cluster installation. It allows configuring primary interface MTU settings, OVN gateway modes to use node routing tables for pod egress, and additional secondary networks such as MACVLAN.

In support of network traffic segregation, multiple network interfaces are configured through the CNO. Traffic steering to these interfaces is configured through static routes applied by using the NMState Operator. To ensure that pod traffic is properly routed, OVN-K is configured with the routingViaHost option enabled. This setting uses the kernel routing table and the applied static routes rather than OVN for pod egress traffic.

The Whereabouts CNI plugin is used to provide dynamic IPv4 and IPv6 addressing for additional pod network interfaces without the use of a DHCP server.

Limits and requirements

OVN-Kubernetes is required for IPv6 support.
Large MTU cluster support requires connected network equipment to be set to the same or larger value.

Engineering considerations

Pod egress traffic is handled by kernel routing table with the routingViaHost option. Appropriate static routes must be configured in the host.

Additional resources

Cluster Network Operator

3.3.3.3.2. Load Balancer

New in this release

Not applicable.

Description

MetalLB is a load-balancer implementation for bare metal Kubernetes clusters using standard routing protocols. It enables a Kubernetes service to get an external IP address which is also added to the host network for the cluster.

Some use cases might require features not available in MetalLB, for example stateful load balancing. Where necessary, you can use an external third party load balancer. Selection and configuration of an external load balancer is outside the scope of this specification. When an external third party load balancer is used, the integration effort must include enough analysis to ensure all performance and resource utilization requirements are met.

Limits and requirements

Stateful load balancing is not supported by MetalLB. An alternate load balancer implementation must be used if this is a requirement for workload CNFs.
The networking infrastructure must ensure that the external IP address is routable from clients to the host network for the cluster.

Engineering considerations

MetalLB is used in BGP mode only for core use case models.
For core use models, MetalLB is supported with only the OVN-Kubernetes network provider used in local gateway mode. See routingViaHost in the "Cluster Network Operator" section.
BGP configuration in MetalLB varies depending on the requirements of the network and peers.
Address pools can be configured as needed, allowing variation in addresses, aggregation length, auto assignment, and other relevant parameters.
The values of parameters in the Bi-Directional Forwarding Detection (BFD) profile should remain close to the defaults. Shorter values might lead to false negatives and impact performance.

Additional resources

About MetalLB and the MetalLB Operator

3.3.3.3.3. SR-IOV

New in this release

Not applicable

Description

SR-IOV enables physical network interfaces (PFs) to be divided into multiple virtual functions (VFs). VFs can then be assigned to multiple pods to achieve higher throughput performance while keeping the pods isolated. The SR-IOV Network Operator provisions and manages SR-IOV CNI, network device plugin, and other components of the SR-IOV stack.

Limits and requirements

The network interface controllers supported are listed in OCP supported SR-IOV devices
SR-IOV and IOMMU enablement in BIOS: The SR-IOV Network Operator automatically enables IOMMU on the kernel command line.
SR-IOV VFs do not receive link state updates from PF. If link down detection is needed, it must be done at the protocol level.

Engineering considerations

SR-IOV interfaces in vfio mode are typically used to enable additional secondary networks for applications that require high throughput or low latency.

Additional resources

About Single Root I/O Virtualization (SR-IOV) hardware networks

3.3.3.3.4. NMState Operator

New in this release

Not applicable

Description

The NMState Operator provides a Kubernetes API for performing network configurations across the cluster’s nodes. It enables network interface configurations, static IPs and DNS, VLANs, trunks, bonding, static routes, MTU, and enabling promiscuous mode on the secondary interfaces. The cluster nodes periodically report on the state of each node’s network interfaces to the API server.

Limits and requirements

Not applicable

Engineering considerations

The initial networking configuration is applied using NMStateConfig content in the installation CRs. The NMState Operator is used only when needed for network updates.
When SR-IOV virtual functions are used for host networking, the NMState Operator using NodeNetworkConfigurationPolicy is used to configure those VF interfaces, for example, VLANs and the MTU.

Additional resources

About the Kubernetes NMState Operator

3.3.3.4. Logging

New in this release

Not applicable

Description

The ClusterLogging Operator enables collection and shipping of logs off the node for remote archival and analysis. The reference configuration ships audit and infrastructure logs to a remote archive by using Kafka.

Limits and requirements

Not applicable

Engineering considerations

The impact of cluster CPU use is based on the number or size of logs generated and the amount of log filtering configured.
The reference configuration does not include shipping of application logs. Inclusion of application logs in the configuration requires evaluation of the application logging rate and sufficient additional CPU resources allocated to the reserved set.

Additional resources

About logging

3.3.3.5. Power Management

New in this release

You can specify a maximum latency that is C-state for a low latency pod when using per-pod power management. Previously, C-states could only be disabled completely on a per pod basis.

Description

The Performance Profile can be used to configure a cluster in a high power, low power or mixed (per-pod power management) mode. The choice of power mode depends on the characteristics of the workloads running on the cluster particularly how sensitive they are to latency.

Limits and requirements

Power configuration relies on appropriate BIOS configuration, for example, enabling C-states and P-states. Configuration varies between hardware vendors.

Engineering considerations

Latency: To ensure that latency-sensitive workloads meet their requirements, you will need either a high-power configuration or a per-pod power management configuration. Per-pod power management is only available for Guaranteed QoS Pods with dedicated pinned CPUs.

Additional resources

Configuring power saving for nodes that run colocated high and low priority workloads

3.3.3.6. Storage

Overview

Cloud native storage services can be provided by multiple solutions including OpenShift Data Foundation from Red Hat or third parties.

OpenShift Data Foundation is a Ceph based software-defined storage solution for containers. It provides block storage, file system storage, and on-premises object storage, which can be dynamically provisioned for both persistent and non-persistent data requirements. Telco core applications require persistent storage.

Note

All storage data may not be encrypted in flight. To reduce risk, isolate the storage network from other cluster networks. The storage network must not be reachable, or routable, from other cluster networks. Only nodes directly attached to the storage network should be allowed to gain access to it.

3.3.3.6.1. OpenShift Data Foundation

New in this release

Not applicable

Description

Red Hat OpenShift Data Foundation is a software-defined storage service for containers. For Telco core clusters, storage support is provided by OpenShift Data Foundation storage services running externally to the application workload cluster. OpenShift Data Foundation supports separation of storage traffic using secondary CNI networks.

Limits and requirements

In an IPv4/IPv6 dual-stack networking environment, OpenShift Data Foundation uses IPv4 addressing. For more information, see Support OpenShift dual stack with ODF using IPv4.

Engineering considerations

OpenShift Data Foundation network traffic should be isolated from other traffic on a dedicated network, for example, by using VLAN isolation.

3.3.3.6.2. Other Storage

Other storage solutions can be used to provide persistent storage for core clusters. The configuration and integration of these solutions is outside the scope of the telco core RDS. Integration of the storage solution into the core cluster must include correct sizing and performance analysis to ensure the storage meets overall performance and resource utilization requirements.

Additional resources

Red Hat OpenShift Data Foundation

3.3.3.7. Monitoring

New in this release

Not applicable

Description

The Cluster Monitoring Operator (CMO) is included by default on all OpenShift clusters and provides monitoring (metrics, dashboards, and alerting) for the platform components and optionally user projects as well.

Configuration of the monitoring operator allows for customization, including:

Default retention period
Custom alert rules

The default handling of pod CPU and memory metrics is based on upstream Kubernetes cAdvisor and makes a tradeoff that prefers handling of stale data over metric accuracy. This leads to spiky data that will create false triggers of alerts over user-specified thresholds. OpenShift supports an opt-in dedicated service monitor feature creating an additional set of pod CPU and memory metrics that do not suffer from the spiky behavior. For additional information, see this solution guide.

In addition to default configuration, the following metrics are expected to be configured for telco core clusters:

Pod CPU and memory metrics and alerts for user workloads

Limits and requirements

Monitoring configuration must enable the dedicated service monitor feature for accurate representation of pod metrics

Engineering considerations

The Prometheus retention period is specified by the user. The value used is a tradeoff between operational requirements for maintaining historical data on the cluster against CPU and storage resources. Longer retention periods increase the need for storage and require additional CPU to manage the indexing of data.

Additional resources

About 4.14 monitoring

3.3.3.8. Scheduling

New in this release

NUMA-aware scheduling with the NUMA Resources Operator is now generally available in OpenShift Container Platform 4.14.
With this release, you can exclude advertising the Non-Uniform Memory Access (NUMA) node for the SR-IOV network to the Topology Manager. By not advertising the NUMA node for the SR-IOV network, you can permit more flexible SR-IOV network deployments during NUMA-aware pod scheduling. To exclude advertising the NUMA node for the SR-IOV network resource to the Topology Manager, set the value excludeTopology to true in the SriovNetworkNodePolicy CR. For more information, see Exclude the SR-IOV network topology for NUMA-aware scheduling.

Description

The scheduler is a cluster-wide component responsible for selecting the right node for a given workload. It is a core part of the platform and does not require any specific configuration in the common deployment scenarios. However, there are few specific use cases described in the following section.

Limits and requirements

The default scheduler does not understand the NUMA locality of workloads. It only knows about the sum of all free resources on a worker node. This might cause workloads to be rejected when scheduled to a node with Topology manager policy set to single-numa-node or restricted.
- For example, consider a pod requesting 6 CPUs and being scheduled to an empty node that has 4 CPUs per NUMA node. The total allocatable capacity of the node is 8 CPUs and the scheduler will place the pod there. The node local admission will fail, however, as there are only 4 CPUs available in each of the NUMA nodes.
- All clusters with multi-NUMA nodes are required to use the NUMA Resources Operator. The machineConfigPoolSelector of the NUMA Resources Operator must select all nodes where NUMA aligned scheduling is needed.
All machine config pools must have consistent hardware configuration for example all nodes are expected to have the same NUMA zone count.

Engineering considerations

Pods might require annotations for correct scheduling and isolation. For more information on annotations, see the "CPU Partitioning and performance tuning" section.

Additional resources

3.3.3.9. Installation

New in this release, Description

Telco core clusters can be installed using the Agent Based Installer (ABI). This method allows users to install OpenShift Container Platform on bare metal servers without requiring additional servers or VMs for managing the installation. The ABI installer can be run on any system for example a laptop to generate an ISO installation image. This ISO is used as the installation media for the cluster supervisor nodes. Progress can be monitored using the ABI tool from any system with network connectivity to the supervisor node’s API interfaces.

Installation from declarative CRs
Does not require additional servers to support installation
Supports install in disconnected environment

Limits and requirements

Disconnected installation requires a reachable registry with all required content mirrored.

Engineering considerations

Networking configuration should be applied as NMState configuration during installation in preference to day-2 configuration by using the NMState Operator.

Additional resources

Installing an OpenShift Container Platform cluster with the Agent-based Installer

3.3.3.10. Security

New in this release

DPDK applications that need to inject traffic to the kernel can run in non-privileged pods with the help of the TAP CNI plugin. Furthermore, in this 4.14 release that ability to create a MAC-VLAN, IP-VLAN, and VLAN subinterface based on a master interface in a container namespace is generally available.

Description

Telco operators are security conscious and require clusters to be hardened against multiple attack vectors. Within OpenShift Container Platform, there is no single component or feature responsible for securing a cluster. This section provides details of security-oriented features and configuration for the use models covered in this specification.

SecurityContextConstraints: All workload pods should be run with restricted-v2 or restricted SCC.
Seccomp: All pods should be run with the RuntimeDefault (or stronger) seccomp profile.
Rootless DPDK pods: Many user-plane networking (DPDK) CNFs require pods to run with root privileges. With this feature, a conformant DPDK pod can be run without requiring root privileges.
Storage: The storage network should be isolated and non-routable to other cluster networks. See the "Storage" section for additional details.

Limits and requirements

Rootless DPDK pods requires the following additional configuration steps:
- Configure the TAP plugin with the container_t SELinux context.
- Enable the container_use_devices SELinux boolean on the hosts.

Engineering considerations

For rootless DPDK pod support, the SELinux boolean container_use_devices must be enabled on the host for the TAP device to be created. This introduces a security risk that is acceptable for short to mid-term use. Other solutions will be explored.

Additional resources

Managing security context constraints

3.3.3.11. Scalability

New in this release

Not applicable

Description

Clusters will scale to the sizing listed in the limits and requirements section.

Scaling of workloads is described in the use model section.

Limits and requirements

Cluster scales to at least 120 nodes

Engineering considerations

Not applicable

3.3.3.12. Additional configuration

3.3.3.12.1. Disconnected environment

Description

Telco core clusters are expected to be installed in networks without direct access to the internet. All container images needed to install, configure, and operator the cluster must be available in a disconnected registry. This includes OpenShift Container Platform images, day-2 Operator Lifecycle Manager (OLM) Operator images, and application workload images. The use of a disconnected environment provides multiple benefits, for example:

Limiting access to the cluster for security
Curated content: The registry is populated based on curated and approved updates for the clusters

Limits and requirements

A unique name is required for all custom CatalogSources. Do not reuse the default catalog names.
A valid time source must be configured as part of cluster installation.

Engineering considerations

Not applicable

3.3.3.12.2. Kernel

New in this release

Not applicable

Description

The user can install the following kernel modules by using MachineConfig to provide extended kernel functionality to CNFs:

sctp
ip_gre
ip6_tables
ip6t_REJECT
ip6table_filter
ip6table_mangle
iptable_filter
iptable_mangle
iptable_nat
xt_multiport
xt_owner
xt_REDIRECT
xt_statistic
xt_TCPMSS

Limits and requirements

Use of functionality available through these kernel modules must be analyzed by the user to determine the impact on CPU load, system performance, and ability to sustain KPI.

Note

Out of tree drivers are not supported.

Engineering considerations

Not applicable

3.3.4. Telco core 4.14 reference configuration CRs

Use the following custom resources (CRs) to configure and deploy OpenShift Container Platform clusters with the telco core profile. Use the CRs to form the common baseline used in all the specific use models unless otherwise indicated.

3.3.4.1. Resource Tuning reference CRs

Table 3.11. Resource Tuning CRs
Component	Reference CR	Optional	New in this release
System reserved capacity	control-plane-system-reserved.yaml	Yes	No
System reserved capacity	pid-limits-cr.yaml	Yes	No

3.3.4.2. Storage reference CRs

Table 3.12. Storage CRs
Component	Reference CR	Optional	New in this release
External ODF configuration	01-rook-ceph-external-cluster-details.secret.yaml	No	Yes
External ODF configuration	02-ocs-external-storagecluster.yaml	No	No
External ODF configuration	odfNS.yaml	No	No
External ODF configuration	odfOperGroup.yaml	No	No

3.3.4.3. Networking reference CRs

Table 3.13. Networking CRs
Component	Reference CR	Optional	New in this release
Baseline	Network.yaml	No	No
Baseline	networkAttachmentDefinition.yaml	Yes	Yes
Load balancer	addr-pool.yaml	No	No
Load balancer	bfd-profile.yaml	No	No
Load balancer	bgp-advr.yaml	No	No
Load balancer	bgp-peer.yaml	No	No
Load balancer	metallb.yaml	No	No
Load balancer	metallbNS.yaml	Yes	No
Load balancer	metallbOperGroup.yaml	Yes	No
Load balancer	metallbSubscription.yaml	No	No
Multus - Tap CNI for rootless DPDK pod	mc_rootless_pods_selinux.yaml	No	No
SR-IOV Network Operator	sriovNetwork.yaml	Yes	No
SR-IOV Network Operator	sriovNetworkNodePolicy.yaml	No	Yes
SR-IOV Network Operator	SriovOperatorConfig.yaml	No	Yes
SR-IOV Network Operator	SriovSubscription.yaml	No	No
SR-IOV Network Operator	SriovSubscriptionNS.yaml	No	No
SR-IOV Network Operator	SriovSubscriptionOperGroup.yaml	No	No

3.3.4.4. Scheduling reference CRs

Table 3.14. Scheduling CRs
Component	Reference CR	Optional	New in this release
NUMA-aware scheduler	nrop.yaml	No	No
NUMA-aware scheduler	NROPSubscription.yaml	No	No
NUMA-aware scheduler	NROPSubscriptionNS.yaml	No	No
NUMA-aware scheduler	NROPSubscriptionOperGroup.yaml	No	No
NUMA-aware scheduler	sched.yaml	No	No

3.3.4.5. Other reference CRs

Table 3.15. Other CRs
Component	Reference CR	Optional	New in this release
Additional kernel modules	control-plane-load-kernel-modules.yaml	Yes	No
Additional kernel modules	sctp_module_mc.yaml	Yes	No
Additional kernel modules	worker-load-kernel-modules.yaml	Yes	No
Cluster logging	ClusterLogForwarder.yaml	No	No
Cluster logging	ClusterLogging.yaml	No	No
Cluster logging	ClusterLogNS.yaml	No	No
Cluster logging	ClusterLogOperGroup.yaml	No	No
Cluster logging	ClusterLogSubscription.yaml	No	Yes
Disconnected configuration	catalog-source.yaml	No	No
Disconnected configuration	icsp.yaml	No	No
Disconnected configuration	operator-hub.yaml	No	No
Monitoring and observability	monitoring-config-cm.yaml	Yes	No
Power management	PerformanceProfile.yaml	No	No

3.3.4.6. YAML reference

3.3.4.6.1. Resource tuning reference YAML

control-plane-system-reserved.yaml

# optional
# count: 1
apiVersion: machineconfiguration.openshift.io/v1
kind: KubeletConfig
metadata:
  name: autosizing-master
spec:
  autoSizingReserved: true
  machineConfigPoolSelector:
    matchLabels:
      pools.operator.machineconfiguration.openshift.io/master: ""

pid-limits-cr.yaml

# optional
# count: 1
apiVersion: machineconfiguration.openshift.io/v1
kind: ContainerRuntimeConfig
metadata:
  name: 99-change-pidslimit-custom
spec:
  machineConfigPoolSelector:
    matchLabels:
      # Set to appropriate MCP
      pools.operator.machineconfiguration.openshift.io/master: ""
  containerRuntimeConfig:
    pidsLimit: $pidsLimit
    # Example:
    #pidsLimit: 4096

3.3.4.6.2. Storage reference YAML

01-rook-ceph-external-cluster-details.secret.yaml

# required
# count: 1
---
apiVersion: v1
kind: Secret
metadata:
  name: rook-ceph-external-cluster-details
  namespace: openshift-storage
type: Opaque
data:
  # encoded content has been made generic
  external_cluster_details: eyJuYW1lIjoicm9vay1jZXBoLW1vbi1lbmRwb2ludHMiLCJraW5kIjoiQ29uZmlnTWFwIiwiZGF0YSI6eyJkYXRhIjoiY2VwaHVzYTE9MS4yLjMuNDo2Nzg5IiwibWF4TW9uSWQiOiIwIiwibWFwcGluZyI6Int9In19LHsibmFtZSI6InJvb2stY2VwaC1tb24iLCJraW5kIjoiU2VjcmV0IiwiZGF0YSI6eyJhZG1pbi1zZWNyZXQiOiJhZG1pbi1zZWNyZXQiLCJmc2lkIjoiMTExMTExMTEtMTExMS0xMTExLTExMTEtMTExMTExMTExMTExIiwibW9uLXNlY3JldCI6Im1vbi1zZWNyZXQifX0seyJuYW1lIjoicm9vay1jZXBoLW9wZXJhdG9yLWNyZWRzIiwia2luZCI6IlNlY3JldCIsImRhdGEiOnsidXNlcklEIjoiY2xpZW50LmhlYWx0aGNoZWNrZXIiLCJ1c2VyS2V5IjoiYzJWamNtVjAifX0seyJuYW1lIjoibW9uaXRvcmluZy1lbmRwb2ludCIsImtpbmQiOiJDZXBoQ2x1c3RlciIsImRhdGEiOnsiTW9uaXRvcmluZ0VuZHBvaW50IjoiMS4yLjMuNCwxLjIuMy4zLDEuMi4zLjIiLCJNb25pdG9yaW5nUG9ydCI6IjkyODMifX0seyJuYW1lIjoiY2VwaC1yYmQiLCJraW5kIjoiU3RvcmFnZUNsYXNzIiwiZGF0YSI6eyJwb29sIjoib2RmX3Bvb2wifX0seyJuYW1lIjoicm9vay1jc2ktcmJkLW5vZGUiLCJraW5kIjoiU2VjcmV0IiwiZGF0YSI6eyJ1c2VySUQiOiJjc2ktcmJkLW5vZGUiLCJ1c2VyS2V5IjoiIn19LHsibmFtZSI6InJvb2stY3NpLXJiZC1wcm92aXNpb25lciIsImtpbmQiOiJTZWNyZXQiLCJkYXRhIjp7InVzZXJJRCI6ImNzaS1yYmQtcHJvdmlzaW9uZXIiLCJ1c2VyS2V5IjoiYzJWamNtVjAifX0seyJuYW1lIjoicm9vay1jc2ktY2VwaGZzLXByb3Zpc2lvbmVyIiwia2luZCI6IlNlY3JldCIsImRhdGEiOnsiYWRtaW5JRCI6ImNzaS1jZXBoZnMtcHJvdmlzaW9uZXIiLCJhZG1pbktleSI6IiJ9fSx7Im5hbWUiOiJyb29rLWNzaS1jZXBoZnMtbm9kZSIsImtpbmQiOiJTZWNyZXQiLCJkYXRhIjp7ImFkbWluSUQiOiJjc2ktY2VwaGZzLW5vZGUiLCJhZG1pbktleSI6ImMyVmpjbVYwIn19LHsibmFtZSI6ImNlcGhmcyIsImtpbmQiOiJTdG9yYWdlQ2xhc3MiLCJkYXRhIjp7ImZzTmFtZSI6ImNlcGhmcyIsInBvb2wiOiJtYW5pbGFfZGF0YSJ9fQ==

02-ocs-external-storagecluster.yaml

# required
# count: 1
---
apiVersion: ocs.openshift.io/v1
kind: StorageCluster
metadata:
  name: ocs-external-storagecluster
  namespace: openshift-storage
spec:
  externalStorage:
    enable: true
  labelSelector: {}

odfNS.yaml

# required: yes
# count: 1
---
apiVersion: v1
kind: Namespace
metadata:
  name: openshift-storage
  annotations:
    workload.openshift.io/allowed: management
  labels:
    openshift.io/cluster-monitoring: "true"

odfOperGroup.yaml

# required: yes
# count: 1
---
apiVersion: operators.coreos.com/v1
kind: OperatorGroup
metadata:
  name: openshift-storage-operatorgroup
  namespace: openshift-storage
spec:
  targetNamespaces:
    - openshift-storage

3.3.4.6.3. Networking reference YAML

Network.yaml

# required
# count: 1
apiVersion: operator.openshift.io/v1
kind: Network
metadata:
  name: cluster
spec:
  defaultNetwork:
    ovnKubernetesConfig:
      gatewayConfig:
        routingViaHost: true
  # additional networks are optional and may alternatively be specified using NetworkAttachmentDefinition CRs
  additionalNetworks: [$additionalNetworks]
  # eg
  #- name: add-net-1
  #  namespace: app-ns-1
  #  rawCNIConfig: '{ "cniVersion": "0.3.1", "name": "add-net-1", "plugins": [{"type": "macvlan", "master": "bond1", "ipam": {}}] }'
  #  type: Raw
  #- name: add-net-2
  #  namespace: app-ns-1
  #  rawCNIConfig: '{ "cniVersion": "0.4.0", "name": "add-net-2", "plugins": [ {"type": "macvlan", "master": "bond1", "mode": "private" },{ "type": "tuning", "name": "tuning-arp" }] }'
  #  type: Raw

networkAttachmentDefinition.yaml

# optional
# copies: 0-N
apiVersion: "k8s.cni.cncf.io/v1"
kind: NetworkAttachmentDefinition
metadata:
  name: $name
  namespace: $ns
spec:
  nodeSelector:
    kubernetes.io/hostname: $nodeName
  config: $config
  #eg
  #config: '{
  #  "cniVersion": "0.3.1",
  #  "name": "external-169",
  #  "type": "vlan",
  #  "master": "ens8f0",
  #  "mode": "bridge",
  #  "vlanid": 169,
  #  "ipam": {
  #    "type": "static",
  #  }
  #}'

addr-pool.yaml

# required
# count: 1-N
apiVersion: metallb.io/v1beta1
kind: IPAddressPool
metadata:
  name: $name # eg addresspool3
  namespace: metallb-system
  annotations:
    metallb.universe.tf/address-pool: $name # eg addresspool3
spec:
  ##############
  # Expected variation in this configuration
  addresses: [$pools]
  #- 3.3.3.0/24
  autoAssign: true
  ##############

bfd-profile.yaml

# required
# count: 1-N
apiVersion: metallb.io/v1beta1
kind: BFDProfile
metadata:
  name: bfdprofile
  namespace: metallb-system
spec:
  ################
  # These values may vary. Recommended values are included as default
  receiveInterval: 150 # default 300ms
  transmitInterval: 150 # default 300ms
  #echoInterval: 300 # default 50ms
  detectMultiplier: 10 # default 3
  echoMode: true
  passiveMode: true
  minimumTtl: 5 # default 254
  #
  ################

bgp-advr.yaml

# required
# count: 1-N
apiVersion: metallb.io/v1beta1
kind: BGPAdvertisement
metadata:
  name: $name # eg bgpadvertisement-1
  namespace: metallb-system
spec:
  ipAddressPools: [$pool]
  # eg:

  #  - addresspool3
  peers: [$peers]
  # eg:

  #    - peer-one
  communities: [$communities]
  # Note correlation with address pool.
  # eg:

  #    - 65535:65282
  aggregationLength: 32
  aggregationLengthV6: 128
  localPref: 100

bgp-peer.yaml

# required
# count: 1-N
apiVersion: metallb.io/v1beta1
kind: BGPPeer
metadata:
  name: $name
  namespace: metallb-system
spec:
  peerAddress: $ip # eg 192.168.1.2
  peerASN: $peerasn # eg 64501
  myASN: $myasn # eg 64500
  routerID: $id # eg 10.10.10.10
  bfdProfile: bfdprofile

metallb.yaml

# required
# count: 1
apiVersion: metallb.io/v1beta1
kind: MetalLB
metadata:
  name: metallb
  namespace: metallb-system
spec:
  nodeSelector:
    node-role.kubernetes.io/worker: ""

metallbNS.yaml

# required: yes
# count: 1
---
apiVersion: v1
kind: Namespace
metadata:
  name: metallb-system
  annotations:
    workload.openshift.io/allowed: management
  labels:
    openshift.io/cluster-monitoring: "true"

metallbOperGroup.yaml

# required: yes
# count: 1
---
apiVersion: operators.coreos.com/v1
kind: OperatorGroup
metadata:
  name: metallb-operator
  namespace: metallb-system

metallbSubscription.yaml

# required: yes
# count: 1
---
apiVersion: operators.coreos.com/v1alpha1
kind: Subscription
metadata:
  name: metallb-operator-sub
  namespace: metallb-system
spec:
  channel: stable
  name: metallb-operator
  source: redhat-operators-disconnected
  sourceNamespace: openshift-marketplace
  installPlanApproval: Automatic

mc_rootless_pods_selinux.yaml

apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: worker
  name: 99-worker-setsebool
spec:
  config:
    ignition:
      version: 3.2.0
    systemd:
      units:
        - contents: |
            [Unit]
            Description=Set SELinux boolean for tap cni plugin
            Before=kubelet.service

            [Service]
            Type=oneshot
            ExecStart=/sbin/setsebool container_use_devices=on
            RemainAfterExit=true

            [Install]
            WantedBy=multi-user.target graphical.target
          enabled: true
          name: setsebool.service

sriovNetwork.yaml

# optional (though expected for all)
# count: 0-N
apiVersion: sriovnetwork.openshift.io/v1
kind: SriovNetwork
metadata:
  name: $name # eg sriov-network-abcd
  namespace: openshift-sriov-network-operator
spec:
  capabilities: "$capabilities" # eg '{"mac": true, "ips": true}'
  ipam: "$ipam" # eg '{ "type": "host-local", "subnet": "10.3.38.0/24" }'
  networkNamespace: $nns # eg cni-test
  resourceName: $resource # eg resourceTest

sriovNetworkNodePolicy.yaml

# optional (though expected in all deployments)
# count: 0-N
apiVersion: sriovnetwork.openshift.io/v1
kind: SriovNetworkNodePolicy
metadata:
  name: $name
  namespace: openshift-sriov-network-operator
spec: {} # $spec
# eg
#deviceType: netdevice
#nicSelector:
#  deviceID: "1593"
#  pfNames:
#  - ens8f0np0#0-9
#  rootDevices:
#  - 0000:d8:00.0
#  vendor: "8086"
#nodeSelector:
#  kubernetes.io/hostname: host.sample.lab
#numVfs: 20
#priority: 99
#excludeTopology: true
#resourceName: resourceNameABCD

SriovOperatorConfig.yaml

# required
# count: 1
---
apiVersion: sriovnetwork.openshift.io/v1
kind: SriovOperatorConfig
metadata:
  name: default
  namespace: openshift-sriov-network-operator
spec:
  configDaemonNodeSelector:
    node-role.kubernetes.io/worker: ""
  enableInjector: true
  enableOperatorWebhook: true

SriovSubscription.yaml

# required: yes
# count: 1
apiVersion: operators.coreos.com/v1alpha1
kind: Subscription
metadata:
  name: sriov-network-operator-subscription
  namespace: openshift-sriov-network-operator
spec:
  channel: "stable"
  name: sriov-network-operator
  source: redhat-operators-disconnected
  sourceNamespace: openshift-marketplace
  installPlanApproval: Automatic

SriovSubscriptionNS.yaml

# required: yes
# count: 1
apiVersion: v1
kind: Namespace
metadata:
  name: openshift-sriov-network-operator
  annotations:
    workload.openshift.io/allowed: management

SriovSubscriptionOperGroup.yaml

# required: yes
# count: 1
apiVersion: operators.coreos.com/v1
kind: OperatorGroup
metadata:
  name: sriov-network-operators
  namespace: openshift-sriov-network-operator
spec:
  targetNamespaces:
    - openshift-sriov-network-operator

3.3.4.6.4. Scheduling reference YAML

nrop.yaml

# Optional
# count: 1
apiVersion: nodetopology.openshift.io/v1
kind: NUMAResourcesOperator
metadata:
  name: numaresourcesoperator
spec:
  nodeGroups:
    - config:
        # Periodic is the default setting
        infoRefreshMode: Periodic
      machineConfigPoolSelector:
        matchLabels:
          # This label must match the pool(s) you want to run NUMA-aligned workloads
          pools.operator.machineconfiguration.openshift.io/worker: ""

NROPSubscription.yaml

# required
# count: 1
apiVersion: operators.coreos.com/v1alpha1
kind: Subscription
metadata:
  name: numaresources-operator
  namespace: openshift-numaresources
spec:
  channel: "4.14"
  name: numaresources-operator
  source: redhat-operators-disconnected
  sourceNamespace: openshift-marketplace

NROPSubscriptionNS.yaml

# required: yes
# count: 1
apiVersion: v1
kind: Namespace
metadata:
  name: openshift-numaresources
  annotations:
    workload.openshift.io/allowed: management

NROPSubscriptionOperGroup.yaml

# required: yes
# count: 1
apiVersion: operators.coreos.com/v1
kind: OperatorGroup
metadata:
  name: numaresources-operator
  namespace: openshift-numaresources
spec:
  targetNamespaces:
    - openshift-numaresources

sched.yaml

# Optional
# count: 1
apiVersion: nodetopology.openshift.io/v1
kind: NUMAResourcesScheduler
metadata:
  name: numaresourcesscheduler
spec:
  #cacheResyncPeriod: "0"
  # Image spec should be the latest for the release
  imageSpec: "registry.redhat.io/openshift4/noderesourcetopology-scheduler-rhel9:v4.14.0"
  #logLevel: "Trace"
  schedulerName: topo-aware-scheduler

3.3.4.6.5. Other reference YAML

control-plane-load-kernel-modules.yaml

# optional
# count: 1
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: master
  name: 40-load-kernel-modules-control-plane
spec:
  config:
    # Release info found in https://github.com/coreos/butane/releases
    ignition:
      version: 3.2.0
    storage:
      files:
        - contents:
            source: data:,
          mode: 420
          overwrite: true
          path: /etc/modprobe.d/kernel-blacklist.conf
        - contents:
            source: data:text/plain;charset=utf-8;base64,aXBfZ3JlCmlwNl90YWJsZXMKaXA2dF9SRUpFQ1QKaXA2dGFibGVfZmlsdGVyCmlwNnRhYmxlX21hbmdsZQppcHRhYmxlX2ZpbHRlcgppcHRhYmxlX21hbmdsZQppcHRhYmxlX25hdAp4dF9tdWx0aXBvcnQKeHRfb3duZXIKeHRfUkVESVJFQ1QKeHRfc3RhdGlzdGljCnh0X1RDUE1TUwp4dF91MzI=
          mode: 420
          overwrite: true
          path: /etc/modules-load.d/kernel-load.conf

sctp_module_mc.yaml

# optional
# count: 1
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: worker
  name: load-sctp-module
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
        - contents:
            source: data:,
            verification: {}
          filesystem: root
          mode: 420
          path: /etc/modprobe.d/sctp-blacklist.conf
        - contents:
            source: data:text/plain;charset=utf-8;base64,c2N0cA==
          filesystem: root
          mode: 420
          path: /etc/modules-load.d/sctp-load.conf

worker-load-kernel-modules.yaml

# optional
# count: 1
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: worker
  name: 40-load-kernel-modules-worker
spec:
  config:
    # Release info found in https://github.com/coreos/butane/releases
    ignition:
      version: 3.2.0
    storage:
      files:
        - contents:
            source: data:,
          mode: 420
          overwrite: true
          path: /etc/modprobe.d/kernel-blacklist.conf
        - contents:
            source: data:text/plain;charset=utf-8;base64,aXBfZ3JlCmlwNl90YWJsZXMKaXA2dF9SRUpFQ1QKaXA2dGFibGVfZmlsdGVyCmlwNnRhYmxlX21hbmdsZQppcHRhYmxlX2ZpbHRlcgppcHRhYmxlX21hbmdsZQppcHRhYmxlX25hdAp4dF9tdWx0aXBvcnQKeHRfb3duZXIKeHRfUkVESVJFQ1QKeHRfc3RhdGlzdGljCnh0X1RDUE1TUwp4dF91MzI=
          mode: 420
          overwrite: true
          path: /etc/modules-load.d/kernel-load.conf

ClusterLogForwarder.yaml

# required
# count: 1
apiVersion: logging.openshift.io/v1
kind: ClusterLogForwarder
metadata:
  name: instance
  namespace: openshift-logging
spec:
  outputs:
    - type: "kafka"
      name: kafka-open
      url: tcp://10.11.12.13:9092/test
  pipelines:
    - inputRefs:
        - infrastructure
        #- application
        - audit
      labels:
        label1: test1
        label2: test2
        label3: test3
        label4: test4
        label5: test5
      name: all-to-default
      outputRefs:
        - kafka-open

ClusterLogging.yaml

# required
# count: 1
apiVersion: logging.openshift.io/v1
kind: ClusterLogging
metadata:
  name: instance
  namespace: openshift-logging
spec:
  collection:
    type: vector
  managementState: Managed

ClusterLogNS.yaml

---
apiVersion: v1
kind: Namespace
metadata:
  name: openshift-logging
  annotations:
    workload.openshift.io/allowed: management

ClusterLogOperGroup.yaml

---
apiVersion: operators.coreos.com/v1
kind: OperatorGroup
metadata:
  name: cluster-logging
  namespace: openshift-logging
spec:
  targetNamespaces:
    - openshift-logging

ClusterLogSubscription.yaml

apiVersion: operators.coreos.com/v1alpha1
kind: Subscription
metadata:
  name: cluster-logging
  namespace: openshift-logging
spec:
  channel: "stable"
  name: cluster-logging
  source: redhat-operators-disconnected
  sourceNamespace: openshift-marketplace
  installPlanApproval: Automatic

catalog-source.yaml

# required
# count: 1..N
apiVersion: operators.coreos.com/v1alpha1
kind: CatalogSource
metadata:
  name: redhat-operators-disconnected
  namespace: openshift-marketplace
spec:
  displayName: Red Hat Disconnected Operators Catalog
  image: $imageUrl
  publisher: Red Hat
  sourceType: grpc
#  updateStrategy:
#    registryPoll:
#      interval: 1h
#status:
#    connectionState:
#        lastObservedState: READY

icsp.yaml

# required
# count: 1
apiVersion: operator.openshift.io/v1alpha1
kind: ImageContentSourcePolicy
metadata:
  name: disconnected-internal-icsp
spec:
  repositoryDigestMirrors: []
#    - $mirrors

operator-hub.yaml

# required
# count: 1
apiVersion: config.openshift.io/v1
kind: OperatorHub
metadata:
  name: cluster
spec:
  disableAllDefaultSources: true

monitoring-config-cm.yaml

# optional
# count: 1
---
apiVersion: v1
kind: ConfigMap
metadata:
  name: cluster-monitoring-config
  namespace: openshift-monitoring
data:
  config.yaml: |
    k8sPrometheusAdapter:
      dedicatedServiceMonitors:
        enabled: true
    prometheusK8s:
      retention: 15d
      volumeClaimTemplate:
        spec:
          storageClassName: ocs-external-storagecluster-ceph-rbd
          resources:
            requests:
              storage: 100Gi
    alertmanagerMain:
      volumeClaimTemplate:
        spec:
          storageClassName: ocs-external-storagecluster-ceph-rbd
          resources:
            requests:
              storage: 20Gi

PerformanceProfile.yaml

# required
# count: 1
apiVersion: performance.openshift.io/v2
kind: PerformanceProfile
metadata:
  name: $name
  annotations:
    # Some pods want the kernel stack to ignore IPv6 router Advertisement.
    kubeletconfig.experimental: |
      {"allowedUnsafeSysctls":["net.ipv6.conf.all.accept_ra"]}
spec:
  cpu:
    # node0 CPUs: 0-17,36-53
    # node1 CPUs: 18-34,54-71
    # siblings: (0,36), (1,37)...
    # we want to reserve the first Core of each NUMA socket
    #
    # no CPU left behind! all-cpus == isolated + reserved
    isolated: $isolated # eg 1-17,19-35,37-53,55-71
    reserved: $reserved # eg 0,18,36,54
  # Guaranteed QoS pods will disable IRQ balancing for cores allocated to the pod.
  # default value of globallyDisableIrqLoadBalancing is false
  globallyDisableIrqLoadBalancing: false
  hugepages:
    defaultHugepagesSize: 1G
    pages:
      # 32GB per numa node
      - count: $count # eg 64
        size: 1G
  machineConfigPoolSelector:
    # For SNO: machineconfiguration.openshift.io/role: 'master'
    pools.operator.machineconfiguration.openshift.io/worker: ''
  nodeSelector:
    # For SNO: node-role.kubernetes.io/master: ""
    node-role.kubernetes.io/worker: ""
  workloadHints:
    realTime: false
    highPowerConsumption: false
    perPodPowerManagement: true
  realTimeKernel:
    enabled: false
  numa:
    # All guaranteed QoS containers get resources from a single NUMA node
    topologyPolicy: "single-numa-node"
  net:
    userLevelNetworking: false

Chapter 4. Planning your environment according to object maximums

Consider the following tested object maximums when you plan your OpenShift Container Platform cluster.

These guidelines are based on the largest possible cluster. For smaller clusters, the maximums are lower. There are many factors that influence the stated thresholds, including the etcd version or storage data format.

In most cases, exceeding these numbers results in lower overall performance. It does not necessarily mean that the cluster will fail.

Warning

Clusters that experience rapid change, such as those with many starting and stopping pods, can have a lower practical maximum size than documented.

4.1. OpenShift Container Platform tested cluster maximums for major releases

Note

Red Hat does not provide direct guidance on sizing your OpenShift Container Platform cluster. This is because determining whether your cluster is within the supported bounds of OpenShift Container Platform requires careful consideration of all the multidimensional factors that limit the cluster scale.

OpenShift Container Platform supports tested cluster maximums rather than absolute cluster maximums. Not every combination of OpenShift Container Platform version, control plane workload, and network plugin are tested, so the following table does not represent an absolute expectation of scale for all deployments. It might not be possible to scale to a maximum on all dimensions simultaneously. The table contains tested maximums for specific workload and deployment configurations, and serves as a scale guide as to what can be expected with similar deployments.

Maximum type	4.x tested maximum
Number of nodes	2,000 ^[1]
Number of pods ^[2]	150,000
Number of pods per node	2,500 ^[3][4]
Number of pods per core	There is no default value.
Number of namespaces ^[5]	10,000
Number of builds	10,000 (Default pod RAM 512 Mi) - Source-to-Image (S2I) build strategy
Number of pods per namespace ^[6]	25,000
Number of routes and back ends per Ingress Controller	2,000 per router
Number of secrets	80,000
Number of config maps	90,000
Number of services ^[7]	10,000
Number of services per namespace	5,000
Number of back-ends per service	5,000
Number of deployments per namespace ^[6]	2,000
Number of build configs	12,000
Number of custom resource definitions (CRD)	1,024 ^[8]

Pause pods were deployed to stress the control plane components of OpenShift Container Platform at 2000 node scale. The ability to scale to similar numbers will vary depending upon specific deployment and workload parameters.
The pod count displayed here is the number of test pods. The actual number of pods depends on the application’s memory, CPU, and storage requirements.
This was tested on a cluster with 31 servers: 3 control planes, 2 infrastructure nodes, and 26 worker nodes. If you need 2,500 user pods, you need both a hostPrefix of 20, which allocates a network large enough for each node to contain more than 2000 pods, and a custom kubelet config with maxPods set to 2500. For more information, see Running 2500 pods per node on OCP 4.13.
The maximum tested pods per node is 2,500 for clusters using the OVNKubernetes network plugin. The maximum tested pods per node for the OpenShiftSDN network plugin is 500 pods.
When there are a large number of active projects, etcd might suffer from poor performance if the keyspace grows excessively large and exceeds the space quota. Periodic maintenance of etcd, including defragmentation, is highly recommended to free etcd storage.
There are several control loops in the system that must iterate over all objects in a given namespace as a reaction to some changes in state. Having a large number of objects of a given type in a single namespace can make those loops expensive and slow down processing given state changes. The limit assumes that the system has enough CPU, memory, and disk to satisfy the application requirements.
Each service port and each service back-end has a corresponding entry in iptables. The number of back-ends of a given service impact the size of the Endpoints objects, which impacts the size of data that is being sent all over the system.
Tested on a cluster with 29 servers: 3 control planes, 2 infrastructure nodes, and 24 worker nodes. The cluster had 500 namespaces. OpenShift Container Platform has a limit of 1,024 total custom resource definitions (CRD), including those installed by OpenShift Container Platform, products integrating with OpenShift Container Platform and user-created CRDs. If there are more than 1,024 CRDs created, then there is a possibility that oc command requests might be throttled.

4.1.1. Example scenario

As an example, 500 worker nodes (m5.2xl) were tested, and are supported, using OpenShift Container Platform 4.14, the OVN-Kubernetes network plugin, and the following workload objects:

200 namespaces, in addition to the defaults
60 pods per node; 30 server and 30 client pods (30k total)
57 image streams/ns (11.4k total)
15 services/ns backed by the server pods (3k total)
15 routes/ns backed by the previous services (3k total)
20 secrets/ns (4k total)
10 config maps/ns (2k total)
6 network policies/ns, including deny-all, allow-from ingress and intra-namespace rules
57 builds/ns

The following factors are known to affect cluster workload scaling, positively or negatively, and should be factored into the scale numbers when planning a deployment. For additional information and guidance, contact your sales representative or Red Hat support.

Number of pods per node
Number of containers per pod
Type of probes used (for example, liveness/readiness, exec/http)
Number of network policies
Number of projects, or namespaces
Number of image streams per project
Number of builds per project
Number of services/endpoints and type
Number of routes
Number of shards
Number of secrets
Number of config maps
Rate of API calls, or the cluster “churn”, which is an estimation of how quickly things change in the cluster configuration.
- Prometheus query for pod creation requests per second over 5 minute windows: sum(irate(apiserver_request_count{resource="pods",verb="POST"}[5m]))
- Prometheus query for all API requests per second over 5 minute windows: sum(irate(apiserver_request_count{}[5m]))
Cluster node resource consumption of CPU
Cluster node resource consumption of memory

4.2. OpenShift Container Platform environment and configuration on which the cluster maximums are tested

4.2.1. AWS cloud platform

Node	Flavor	vCPU	RAM(GiB)	Disk type	Disk size(GiB)/IOS	Count	Region
Control plane/etcd ^[1]	r5.4xlarge	16	128	gp3	220	3	us-west-2
Infra ^[2]	m5.12xlarge	48	192	gp3	100	3	us-west-2
Workload ^[3]	m5.4xlarge	16	64	gp3	500 ^[4]	1	us-west-2
Compute	m5.2xlarge	8	32	gp3	100	3/25/250/500 ^[5]	us-west-2

gp3 disks with a baseline performance of 3000 IOPS and 125 MiB per second are used for control plane/etcd nodes because etcd is latency sensitive. gp3 volumes do not use burst performance.
Infra nodes are used to host Monitoring, Ingress, and Registry components to ensure they have enough resources to run at large scale.
Workload node is dedicated to run performance and scalability workload generators.
Larger disk size is used so that there is enough space to store the large amounts of data that is collected during the performance and scalability test run.
Cluster is scaled in iterations and performance and scalability tests are executed at the specified node counts.

4.2.2. IBM Power platform

Node	vCPU	RAM(GiB)	Disk type	Disk size(GiB)/IOS	Count
Control plane/etcd ^[1]	16	32	io1	120 / 10 IOPS per GiB	3
Infra ^[2]	16	64	gp2	120	2
Workload ^[3]	16	256	gp2	120 ^[4]	1
Compute	16	64	gp2	120	2 to 100 ^[5]

io1 disks with 120 / 10 IOPS per GiB are used for control plane/etcd nodes as etcd is I/O intensive and latency sensitive.
Infra nodes are used to host Monitoring, Ingress, and Registry components to ensure they have enough resources to run at large scale.
Workload node is dedicated to run performance and scalability workload generators.
Larger disk size is used so that there is enough space to store the large amounts of data that is collected during the performance and scalability test run.
Cluster is scaled in iterations.

4.2.3. IBM Z platform

Node	vCPU ^[4]	RAM(GiB)^[5]	Disk type	Disk size(GiB)/IOS	Count
Control plane/etcd ^[1,2]	8	32	ds8k	300 / LCU 1	3
Compute ^[1,3]	8	32	ds8k	150 / LCU 2	4 nodes (scaled to 100/250/500 pods per node)

Nodes are distributed between two logical control units (LCUs) to optimize disk I/O load of the control plane/etcd nodes as etcd is I/O intensive and latency sensitive. Etcd I/O demand should not interfere with other workloads.
Four compute nodes are used for the tests running several iterations with 100/250/500 pods at the same time. First, idling pods were used to evaluate if pods can be instanced. Next, a network and CPU demanding client/server workload were used to evaluate the stability of the system under stress. Client and server pods were pairwise deployed and each pair was spread over two compute nodes.
No separate workload node was used. The workload simulates a microservice workload between two compute nodes.
Physical number of processors used is six Integrated Facilities for Linux (IFLs).
Total physical memory used is 512 GiB.

4.3. How to plan your environment according to tested cluster maximums

Important

Oversubscribing the physical resources on a node affects resource guarantees the Kubernetes scheduler makes during pod placement. Learn what measures you can take to avoid memory swapping.

Some of the tested maximums are stretched only in a single dimension. They will vary when many objects are running on the cluster.

The numbers noted in this documentation are based on Red Hat’s test methodology, setup, configuration, and tunings. These numbers can vary based on your own individual setup and environments.

While planning your environment, determine how many pods are expected to fit per node:

required pods per cluster / pods per node = total number of nodes needed

The default maximum number of pods per node is 250. However, the number of pods that fit on a node is dependent on the application itself. Consider the application’s memory, CPU, and storage requirements, as described in "How to plan your environment according to application requirements".

Example scenario

If you want to scope your cluster for 2200 pods per cluster, you would need at least five nodes, assuming that there are 500 maximum pods per node:

2200 / 500 = 4.4

If you increase the number of nodes to 20, then the pod distribution changes to 110 pods per node:

2200 / 20 = 110

Where:

required pods per cluster / total number of nodes = expected pods per node

OpenShift Container Platform comes with several system pods, such as SDN, DNS, Operators, and others, which run across every worker node by default. Therefore, the result of the above formula can vary.

4.4. How to plan your environment according to application requirements

Consider an example application environment:

Pod type	Pod quantity	Max memory	CPU cores	Persistent storage
apache	100	500 MB	0.5	1 GB
node.js	200	1 GB	1	1 GB
postgresql	100	1 GB	2	10 GB
JBoss EAP	100	1 GB	1	1 GB

Extrapolated requirements: 550 CPU cores, 450GB RAM, and 1.4TB storage.

Instance size for nodes can be modulated up or down, depending on your preference. Nodes are often resource overcommitted. In this deployment scenario, you can choose to run additional smaller nodes or fewer larger nodes to provide the same amount of resources. Factors such as operational agility and cost-per-instance should be considered.

Node type	Quantity	CPUs	RAM (GB)
Nodes (option 1)	100	4	16
Nodes (option 2)	50	8	32
Nodes (option 3)	25	16	64

Some applications lend themselves well to overcommitted environments, and some do not. Most Java applications and applications that use huge pages are examples of applications that would not allow for overcommitment. That memory can not be used for other applications. In the example above, the environment would be roughly 30 percent overcommitted, a common ratio.

The application pods can access a service either by using environment variables or DNS. If using environment variables, for each active service the variables are injected by the kubelet when a pod is run on a node. A cluster-aware DNS server watches the Kubernetes API for new services and creates a set of DNS records for each one. If DNS is enabled throughout your cluster, then all pods should automatically be able to resolve services by their DNS name. Service discovery using DNS can be used in case you must go beyond 5000 services. When using environment variables for service discovery, the argument list exceeds the allowed length after 5000 services in a namespace, then the pods and deployments will start failing. Disable the service links in the deployment’s service specification file to overcome this:

---
apiVersion: template.openshift.io/v1
kind: Template
metadata:
  name: deployment-config-template
  creationTimestamp:
  annotations:
    description: This template will create a deploymentConfig with 1 replica, 4 env vars and a service.
    tags: ''
objects:
- apiVersion: apps.openshift.io/v1
  kind: DeploymentConfig
  metadata:
    name: deploymentconfig${IDENTIFIER}
  spec:
    template:
      metadata:
        labels:
          name: replicationcontroller${IDENTIFIER}
      spec:
        enableServiceLinks: false
        containers:
        - name: pause${IDENTIFIER}
          image: "${IMAGE}"
          ports:
          - containerPort: 8080
            protocol: TCP
          env:
          - name: ENVVAR1_${IDENTIFIER}
            value: "${ENV_VALUE}"
          - name: ENVVAR2_${IDENTIFIER}
            value: "${ENV_VALUE}"
          - name: ENVVAR3_${IDENTIFIER}
            value: "${ENV_VALUE}"
          - name: ENVVAR4_${IDENTIFIER}
            value: "${ENV_VALUE}"
          resources: {}
          imagePullPolicy: IfNotPresent
          capabilities: {}
          securityContext:
            capabilities: {}
            privileged: false
        restartPolicy: Always
        serviceAccount: ''
    replicas: 1
    selector:
      name: replicationcontroller${IDENTIFIER}
    triggers:
    - type: ConfigChange
    strategy:
      type: Rolling
- apiVersion: v1
  kind: Service
  metadata:
    name: service${IDENTIFIER}
  spec:
    selector:
      name: replicationcontroller${IDENTIFIER}
    ports:
    - name: serviceport${IDENTIFIER}
      protocol: TCP
      port: 80
      targetPort: 8080
    clusterIP: ''
    type: ClusterIP
    sessionAffinity: None
  status:
    loadBalancer: {}
parameters:
- name: IDENTIFIER
  description: Number to append to the name of resources
  value: '1'
  required: true
- name: IMAGE
  description: Image to use for deploymentConfig
  value: gcr.io/google-containers/pause-amd64:3.0
  required: false
- name: ENV_VALUE
  description: Value to use for environment variables
  generate: expression
  from: "[A-Za-z0-9]{255}"
  required: false
labels:
  template: deployment-config-template

The number of application pods that can run in a namespace is dependent on the number of services and the length of the service name when the environment variables are used for service discovery. ARG_MAX on the system defines the maximum argument length for a new process and it is set to 2097152 bytes (2 MiB) by default. The Kubelet injects environment variables in to each pod scheduled to run in the namespace including:

<SERVICE_NAME>_SERVICE_HOST=<IP>
<SERVICE_NAME>_SERVICE_PORT=<PORT>
<SERVICE_NAME>_PORT=tcp://<IP>:<PORT>
<SERVICE_NAME>_PORT_<PORT>_TCP=tcp://<IP>:<PORT>
<SERVICE_NAME>_PORT_<PORT>_TCP_PROTO=tcp
<SERVICE_NAME>_PORT_<PORT>_TCP_PORT=<PORT>
<SERVICE_NAME>_PORT_<PORT>_TCP_ADDR=<ADDR>

The pods in the namespace will start to fail if the argument length exceeds the allowed value and the number of characters in a service name impacts it. For example, in a namespace with 5000 services, the limit on the service name is 33 characters, which enables you to run 5000 pods in the namespace.

Chapter 5. Using quotas and limit ranges

A resource quota, defined by a ResourceQuota object, provides constraints that limit aggregate resource consumption per project. It can limit the quantity of objects that can be created in a project by type, as well as the total amount of compute resources and storage that may be consumed by resources in that project.

Using quotas and limit ranges, cluster administrators can set constraints to limit the number of objects or amount of compute resources that are used in your project. This helps cluster administrators better manage and allocate resources across all projects, and ensure that no projects are using more than is appropriate for the cluster size.

Important

Quotas are set by cluster administrators and are scoped to a given project. OpenShift Container Platform project owners can change quotas for their project, but not limit ranges. OpenShift Container Platform users cannot modify quotas or limit ranges.

The following sections help you understand how to check on your quota and limit range settings, what sorts of things they can constrain, and how you can request or limit compute resources in your own pods and containers.

5.1. Resources managed by quota

The following describes the set of compute resources and object types that may be managed by a quota.

Note

A pod is in a terminal state if status.phase is Failed or Succeeded.

Table 5.1. Compute resources managed by quota
Resource Name	Description
`cpu`	The sum of CPU requests across all pods in a non-terminal state cannot exceed this value. `cpu` and `requests.cpu` are the same value and can be used interchangeably.
`memory`	The sum of memory requests across all pods in a non-terminal state cannot exceed this value. `memory` and `requests.memory` are the same value and can be used interchangeably.
`ephemeral-storage`	The sum of local ephemeral storage requests across all pods in a non-terminal state cannot exceed this value. `ephemeral-storage` and `requests.ephemeral-storage` are the same value and can be used interchangeably. This resource is available only if you enabled the ephemeral storage technology preview. This feature is disabled by default.
`requests.cpu`	The sum of CPU requests across all pods in a non-terminal state cannot exceed this value. `cpu` and `requests.cpu` are the same value and can be used interchangeably.
`requests.memory`	The sum of memory requests across all pods in a non-terminal state cannot exceed this value. `memory` and `requests.memory` are the same value and can be used interchangeably.
`requests.ephemeral-storage`	The sum of ephemeral storage requests across all pods in a non-terminal state cannot exceed this value. `ephemeral-storage` and `requests.ephemeral-storage` are the same value and can be used interchangeably. This resource is available only if you enabled the ephemeral storage technology preview. This feature is disabled by default.
`limits.cpu`	The sum of CPU limits across all pods in a non-terminal state cannot exceed this value.
`limits.memory`	The sum of memory limits across all pods in a non-terminal state cannot exceed this value.
`limits.ephemeral-storage`	The sum of ephemeral storage limits across all pods in a non-terminal state cannot exceed this value. This resource is available only if you enabled the ephemeral storage technology preview. This feature is disabled by default.

Table 5.2. Storage resources managed by quota
Resource Name	Description
`requests.storage`	The sum of storage requests across all persistent volume claims in any state cannot exceed this value.
`persistentvolumeclaims`	The total number of persistent volume claims that can exist in the project.
`<storage-class-name>.storageclass.storage.k8s.io/requests.storage`	The sum of storage requests across all persistent volume claims in any state that have a matching storage class, cannot exceed this value.
`<storage-class-name>.storageclass.storage.k8s.io/persistentvolumeclaims`	The total number of persistent volume claims with a matching storage class that can exist in the project.

Table 5.3. Object counts managed by quota
Resource Name	Description
`pods`	The total number of pods in a non-terminal state that can exist in the project.
`replicationcontrollers`	The total number of replication controllers that can exist in the project.
`resourcequotas`	The total number of resource quotas that can exist in the project.
`services`	The total number of services that can exist in the project.
`secrets`	The total number of secrets that can exist in the project.
`configmaps`	The total number of `ConfigMap` objects that can exist in the project.
`persistentvolumeclaims`	The total number of persistent volume claims that can exist in the project.
`openshift.io/imagestreams`	The total number of image streams that can exist in the project.

You can configure an object count quota for these standard namespaced resource types using the count/<resource>.<group> syntax.

$ oc create quota <name> --hard=count/<resource>.<group>=<quota> 1

1: <resource> is the name of the resource, and <group> is the API group, if applicable. Use the kubectl api-resources command for a list of resources and their associated API groups.

5.1.1. Setting resource quota for extended resources

Overcommitment of resources is not allowed for extended resources, so you must specify requests and limits for the same extended resource in a quota. Currently, only quota items with the prefix requests. are allowed for extended resources. The following is an example scenario of how to set resource quota for the GPU resource nvidia.com/gpu.

Procedure

To determine how many GPUs are available on a node in your cluster, use the following command:

$ oc describe node ip-172-31-27-209.us-west-2.compute.internal | egrep 'Capacity|Allocatable|gpu'

Example output

                    openshift.com/gpu-accelerator=true
Capacity:
 nvidia.com/gpu:  2
Allocatable:
 nvidia.com/gpu:  2
 nvidia.com/gpu:  0           0

In this example, 2 GPUs are available.

Use this command to set a quota in the namespace nvidia. In this example, the quota is 1:

$ cat gpu-quota.yaml

Example output

apiVersion: v1
kind: ResourceQuota
metadata:
  name: gpu-quota
  namespace: nvidia
spec:
  hard:
    requests.nvidia.com/gpu: 1

Create the quota with the following command:

$ oc create -f gpu-quota.yaml

Example output

resourcequota/gpu-quota created

Verify that the namespace has the correct quota set using the following command:

$ oc describe quota gpu-quota -n nvidia

Example output

Name:                    gpu-quota
Namespace:               nvidia
Resource                 Used  Hard
--------                 ----  ----
requests.nvidia.com/gpu  0     1

Run a pod that asks for a single GPU with the following command:

$ oc create pod gpu-pod.yaml

Example output

apiVersion: v1
kind: Pod
metadata:
  generateName: gpu-pod-s46h7
  namespace: nvidia
spec:
  restartPolicy: OnFailure
  containers:
  - name: rhel7-gpu-pod
    image: rhel7
    env:
      - name: NVIDIA_VISIBLE_DEVICES
        value: all
      - name: NVIDIA_DRIVER_CAPABILITIES
        value: "compute,utility"
      - name: NVIDIA_REQUIRE_CUDA
        value: "cuda>=5.0"

    command: ["sleep"]
    args: ["infinity"]

    resources:
      limits:
        nvidia.com/gpu: 1

Verify that the pod is running bwith the following command:

$ oc get pods

Example output

NAME              READY     STATUS      RESTARTS   AGE
gpu-pod-s46h7     1/1       Running     0          1m

Verify that the quota Used counter is correct by running the following command:

$ oc describe quota gpu-quota -n nvidia

Example output

Name:                    gpu-quota
Namespace:               nvidia
Resource                 Used  Hard
--------                 ----  ----
requests.nvidia.com/gpu  1     1

Using the following command, attempt to create a second GPU pod in the nvidia namespace. This is technically available on the node because it has 2 GPUs:
```
$ oc create -f gpu-pod.yaml
```
Example output
```
Error from server (Forbidden): error when creating "gpu-pod.yaml": pods "gpu-pod-f7z2w" is forbidden: exceeded quota: gpu-quota, requested: requests.nvidia.com/gpu=1, used: requests.nvidia.com/gpu=1, limited: requests.nvidia.com/gpu=1
```
This Forbidden error message occurs because you have a quota of 1 GPU and this pod tried to allocate a second GPU, which exceeds its quota.

5.1.2. Quota scopes

Each quota can have an associated set of scopes. A quota only measures usage for a resource if it matches the intersection of enumerated scopes.

Adding a scope to a quota restricts the set of resources to which that quota can apply. Specifying a resource outside of the allowed set results in a validation error.

Scope	Description
`Terminating`	Match pods where `spec.activeDeadlineSeconds >= 0`.
`NotTerminating`	Match pods where `spec.activeDeadlineSeconds` is `nil`.
`BestEffort`	Match pods that have best effort quality of service for either `cpu` or `memory`.
`otBestEffort`	Match pods that do not have best effort quality of service for `cpu` and `memory`.

A BestEffort scope restricts a quota to limiting the following resources:

pods

A Terminating, NotTerminating, and NotBestEffort scope restricts a quota to tracking the following resources:

pods
memory
requests.memory
limits.memory
cpu
requests.cpu
limits.cpu
ephemeral-storage
requests.ephemeral-storage
limits.ephemeral-storage

Note

Ephemeral storage requests and limits apply only if you enabled the ephemeral storage technology preview. This feature is disabled by default.

Additional resources

See Resources managed by quotas for more on compute resources.

See Quality of Service Classes for more on committing compute resources.

5.2. Admin quota usage

5.2.1. Quota enforcement

After a resource quota for a project is first created, the project restricts the ability to create any new resources that can violate a quota constraint until it has calculated updated usage statistics.

After a quota is created and usage statistics are updated, the project accepts the creation of new content. When you create or modify resources, your quota usage is incremented immediately upon the request to create or modify the resource.

When you delete a resource, your quota use is decremented during the next full recalculation of quota statistics for the project.

A configurable amount of time determines how long it takes to reduce quota usage statistics to their current observed system value.

If project modifications exceed a quota usage limit, the server denies the action, and an appropriate error message is returned to the user explaining the quota constraint violated, and what their currently observed usage stats are in the system.

5.2.2. Requests compared to limits

When allocating compute resources by quota, each container can specify a request and a limit value each for CPU, memory, and ephemeral storage. Quotas can restrict any of these values.

If the quota has a value specified for requests.cpu or requests.memory, then it requires that every incoming container make an explicit request for those resources. If the quota has a value specified for limits.cpu or limits.memory, then it requires that every incoming container specify an explicit limit for those resources.

5.2.3. Sample resource quota definitions

Example core-object-counts.yaml

apiVersion: v1
kind: ResourceQuota
metadata:
  name: core-object-counts
spec:
  hard:
    configmaps: "10" 1
    persistentvolumeclaims: "4" 2
    replicationcontrollers: "20" 3
    secrets: "10" 4
    services: "10" 5

1: The total number of ConfigMap objects that can exist in the project.
2: The total number of persistent volume claims (PVCs) that can exist in the project.
3: The total number of replication controllers that can exist in the project.
4: The total number of secrets that can exist in the project.
5: The total number of services that can exist in the project.

Example openshift-object-counts.yaml

apiVersion: v1
kind: ResourceQuota
metadata:
  name: openshift-object-counts
spec:
  hard:
    openshift.io/imagestreams: "10" 1

1: The total number of image streams that can exist in the project.

Example compute-resources.yaml

apiVersion: v1
kind: ResourceQuota
metadata:
  name: compute-resources
spec:
  hard:
    pods: "4" 1
    requests.cpu: "1" 2
    requests.memory: 1Gi 3
    requests.ephemeral-storage: 2Gi 4
    limits.cpu: "2" 5
    limits.memory: 2Gi 6
    limits.ephemeral-storage: 4Gi 7

1: The total number of pods in a non-terminal state that can exist in the project.
2: Across all pods in a non-terminal state, the sum of CPU requests cannot exceed 1 core.
3: Across all pods in a non-terminal state, the sum of memory requests cannot exceed 1Gi.
4: Across all pods in a non-terminal state, the sum of ephemeral storage requests cannot exceed 2Gi.
5: Across all pods in a non-terminal state, the sum of CPU limits cannot exceed 2 cores.
6: Across all pods in a non-terminal state, the sum of memory limits cannot exceed 2Gi.
7: Across all pods in a non-terminal state, the sum of ephemeral storage limits cannot exceed 4Gi.

Example besteffort.yaml

apiVersion: v1
kind: ResourceQuota
metadata:
  name: besteffort
spec:
  hard:
    pods: "1" 1
  scopes:
  - BestEffort 2

1: The total number of pods in a non-terminal state with BestEffort quality of service that can exist in the project.
2: Restricts the quota to only matching pods that have BestEffort quality of service for either memory or CPU.

Example compute-resources-long-running.yaml

apiVersion: v1
kind: ResourceQuota
metadata:
  name: compute-resources-long-running
spec:
  hard:
    pods: "4" 1
    limits.cpu: "4" 2
    limits.memory: "2Gi" 3
    limits.ephemeral-storage: "4Gi" 4
  scopes:
  - NotTerminating 5

1: The total number of pods in a non-terminal state.
2: Across all pods in a non-terminal state, the sum of CPU limits cannot exceed this value.
3: Across all pods in a non-terminal state, the sum of memory limits cannot exceed this value.
4: Across all pods in a non-terminal state, the sum of ephemeral storage limits cannot exceed this value.
5: Restricts the quota to only matching pods where spec.activeDeadlineSeconds is set to nil. Build pods will fall under NotTerminating unless the RestartNever policy is applied.

Example compute-resources-time-bound.yaml

apiVersion: v1
kind: ResourceQuota
metadata:
  name: compute-resources-time-bound
spec:
  hard:
    pods: "2" 1
    limits.cpu: "1" 2
    limits.memory: "1Gi" 3
    limits.ephemeral-storage: "1Gi" 4
  scopes:
  - Terminating 5

1: The total number of pods in a non-terminal state.
2: Across all pods in a non-terminal state, the sum of CPU limits cannot exceed this value.
3: Across all pods in a non-terminal state, the sum of memory limits cannot exceed this value.
4: Across all pods in a non-terminal state, the sum of ephemeral storage limits cannot exceed this value.
5: Restricts the quota to only matching pods where spec.activeDeadlineSeconds >=0. For example, this quota would charge for build pods, but not long running pods such as a web server or database.

Example storage-consumption.yaml

apiVersion: v1
kind: ResourceQuota
metadata:
  name: storage-consumption
spec:
  hard:
    persistentvolumeclaims: "10" 1
    requests.storage: "50Gi" 2
    gold.storageclass.storage.k8s.io/requests.storage: "10Gi" 3
    silver.storageclass.storage.k8s.io/requests.storage: "20Gi" 4
    silver.storageclass.storage.k8s.io/persistentvolumeclaims: "5" 5
    bronze.storageclass.storage.k8s.io/requests.storage: "0" 6
    bronze.storageclass.storage.k8s.io/persistentvolumeclaims: "0" 7

1: The total number of persistent volume claims in a project
2: Across all persistent volume claims in a project, the sum of storage requested cannot exceed this value.
3: Across all persistent volume claims in a project, the sum of storage requested in the gold storage class cannot exceed this value.
4: Across all persistent volume claims in a project, the sum of storage requested in the silver storage class cannot exceed this value.
5: Across all persistent volume claims in a project, the total number of claims in the silver storage class cannot exceed this value.
6: Across all persistent volume claims in a project, the sum of storage requested in the bronze storage class cannot exceed this value. When this is set to 0, it means bronze storage class cannot request storage.
7: Across all persistent volume claims in a project, the sum of storage requested in the bronze storage class cannot exceed this value. When this is set to 0, it means bronze storage class cannot create claims.

5.2.4. Creating a quota

To create a quota, first define the quota in a file. Then use that file to apply it to a project. See the Additional resources section for a link describing this.

$ oc create -f <resource_quota_definition> [-n <project_name>]

Here is an example using the core-object-counts.yaml resource quota definition and the demoproject project name:

$ oc create -f core-object-counts.yaml -n demoproject

5.2.5. Creating object count quotas

You can create an object count quota for all OpenShift Container Platform standard namespaced resource types, such as BuildConfig, and DeploymentConfig. An object quota count places a defined quota on all standard namespaced resource types.

When using a resource quota, an object is charged against the quota if it exists in server storage. These types of quotas are useful to protect against exhaustion of storage resources.

To configure an object count quota for a resource, run the following command:

$ oc create quota <name> --hard=count/<resource>.<group>=<quota>,count/<resource>.<group>=<quota>

Example showing object count quota:

$ oc create quota test --hard=count/deployments.extensions=2,count/replicasets.extensions=4,count/pods=3,count/secrets=4
resourcequota "test" created

$ oc describe quota test
Name:                         test
Namespace:                    quota
Resource                      Used  Hard
--------                      ----  ----
count/deployments.extensions  0     2
count/pods                    0     3
count/replicasets.extensions  0     4
count/secrets                 0     4

This example limits the listed resources to the hard limit in each project in the cluster.

5.2.6. Viewing a quota

You can view usage statistics related to any hard limits defined in a project’s quota by navigating in the web console to the project’s Quota page.

You can also use the CLI to view quota details:

First, get the list of quotas defined in the project. For example, for a project called demoproject:

$ oc get quota -n demoproject
NAME                AGE
besteffort          11m
compute-resources   2m
core-object-counts  29m

Describe the quota you are interested in, for example the core-object-counts quota:

$ oc describe quota core-object-counts -n demoproject
Name:			core-object-counts
Namespace:		demoproject
Resource		Used	Hard
--------		----	----
configmaps		3	10
persistentvolumeclaims	0	4
replicationcontrollers	3	20
secrets			9	10
services		2	10

5.2.7. Configuring quota synchronization period

When a set of resources are deleted, the synchronization time frame of resources is determined by the resource-quota-sync-period setting in the /etc/origin/master/master-config.yaml file.

Before quota usage is restored, a user can encounter problems when attempting to reuse the resources. You can change the resource-quota-sync-period setting to have the set of resources regenerate in the needed amount of time (in seconds) for the resources to be once again available:

Example resource-quota-sync-period setting

kubernetesMasterConfig:
  apiLevels:
  - v1beta3
  - v1
  apiServerArguments: null
  controllerArguments:
    resource-quota-sync-period:
      - "10s"

After making any changes, restart the controller services to apply them.

$ master-restart api
$ master-restart controllers

Adjusting the regeneration time can be helpful for creating resources and determining resource usage when automation is used.

Note

The resource-quota-sync-period setting balances system performance. Reducing the sync period can result in a heavy load on the controller.

5.2.8. Explicit quota to consume a resource

If a resource is not managed by quota, a user has no restriction on the amount of resource that can be consumed. For example, if there is no quota on storage related to the gold storage class, the amount of gold storage a project can create is unbounded.

For high-cost compute or storage resources, administrators can require an explicit quota be granted to consume a resource. For example, if a project was not explicitly given quota for storage related to the gold storage class, users of that project would not be able to create any storage of that type.

In order to require explicit quota to consume a particular resource, the following stanza should be added to the master-config.yaml.

admissionConfig:
  pluginConfig:
    ResourceQuota:
      configuration:
        apiVersion: resourcequota.admission.k8s.io/v1alpha1
        kind: Configuration
        limitedResources:
        - resource: persistentvolumeclaims 1
        matchContains:
        - gold.storageclass.storage.k8s.io/requests.storage 2

1: The group or resource to whose consumption is limited by default.
2: The name of the resource tracked by quota associated with the group/resource to limit by default.

In the above example, the quota system intercepts every operation that creates or updates a PersistentVolumeClaim. It checks what resources controlled by quota would be consumed. If there is no covering quota for those resources in the project, the request is denied. In this example, if a user creates a PersistentVolumeClaim that uses storage associated with the gold storage class and there is no matching quota in the project, the request is denied.

Additional resources

For examples of how to create the file needed to set quotas, see Resources managed by quotas.

A description of how to allocate compute resources managed by quota.

For information on managing limits and quota on project resources, see Working with projects.

If a quota has been defined for your project, see Understanding deployments for considerations in cluster configurations.

5.3. Setting limit ranges

A limit range, defined by a LimitRange object, defines compute resource constraints at the pod, container, image, image stream, and persistent volume claim level. The limit range specifies the amount of resources that a pod, container, image, image stream, or persistent volume claim can consume.

All requests to create and modify resources are evaluated against each LimitRange object in the project. If the resource violates any of the enumerated constraints, the resource is rejected. If the resource does not set an explicit value, and if the constraint supports a default value, the default value is applied to the resource.

For CPU and memory limits, if you specify a maximum value but do not specify a minimum limit, the resource can consume more CPU and memory resources than the maximum value.

Core limit range object definition

apiVersion: "v1"
kind: "LimitRange"
metadata:
  name: "core-resource-limits" 1
spec:
  limits:
    - type: "Pod"
      max:
        cpu: "2" 2
        memory: "1Gi" 3
      min:
        cpu: "200m" 4
        memory: "6Mi" 5
    - type: "Container"
      max:
        cpu: "2" 6
        memory: "1Gi" 7
      min:
        cpu: "100m" 8
        memory: "4Mi" 9
      default:
        cpu: "300m" 10
        memory: "200Mi" 11
      defaultRequest:
        cpu: "200m" 12
        memory: "100Mi" 13
      maxLimitRequestRatio:
        cpu: "10" 14

1: The name of the limit range object.
2: The maximum amount of CPU that a pod can request on a node across all containers.
3: The maximum amount of memory that a pod can request on a node across all containers.
4: The minimum amount of CPU that a pod can request on a node across all containers. If you do not set a min value or you set min to 0, the result is no limit and the pod can consume more than the max CPU value.
5: The minimum amount of memory that a pod can request on a node across all containers. If you do not set a min value or you set min to 0, the result is no limit and the pod can consume more than the max memory value.
6: The maximum amount of CPU that a single container in a pod can request.
7: The maximum amount of memory that a single container in a pod can request.
8: The minimum amount of CPU that a single container in a pod can request. If you do not set a min value or you set min to 0, the result is no limit and the pod can consume more than the max CPU value.
9: The minimum amount of memory that a single container in a pod can request. If you do not set a min value or you set min to 0, the result is no limit and the pod can consume more than the max memory value.
10: The default CPU limit for a container if you do not specify a limit in the pod specification.
11: The default memory limit for a container if you do not specify a limit in the pod specification.
12: The default CPU request for a container if you do not specify a request in the pod specification.
13: The default memory request for a container if you do not specify a request in the pod specification.
14: The maximum limit-to-request ratio for a container.

OpenShift Container Platform Limit range object definition

apiVersion: "v1"
kind: "LimitRange"
metadata:
  name: "openshift-resource-limits"
spec:
  limits:
    - type: openshift.io/Image
      max:
        storage: 1Gi 1
    - type: openshift.io/ImageStream
      max:
        openshift.io/image-tags: 20 2
        openshift.io/images: 30 3
    - type: "Pod"
      max:
        cpu: "2" 4
        memory: "1Gi" 5
        ephemeral-storage: "1Gi" 6
      min:
        cpu: "1" 7
        memory: "1Gi" 8

1: The maximum size of an image that can be pushed to an internal registry.
2: The maximum number of unique image tags as defined in the specification for the image stream.
3: The maximum number of unique image references as defined in the specification for the image stream status.
4: The maximum amount of CPU that a pod can request on a node across all containers.
5: The maximum amount of memory that a pod can request on a node across all containers.
6: The maximum amount of ephemeral storage that a pod can request on a node across all containers.
7: The minimum amount of CPU that a pod can request on a node across all containers. See the Supported Constraints table for important information.
8: The minimum amount of memory that a pod can request on a node across all containers. If you do not set a min value or you set min to 0, the result` is no limit and the pod can consume more than the max memory value.

You can specify both core and OpenShift Container Platform resources in one limit range object.

5.3.1. Container limits

Supported Resources:

CPU
Memory

Supported Constraints

Per container, the following must hold true if specified:

Container

Constraint Behavior

Constraint	Behavior
`Min`	`Min[<resource>]` less than or equal to `container.resources.requests[<resource>]` (required) less than or equal to `container/resources.limits[<resource>]` (optional) If the configuration defines a `min` CPU, the request value must be greater than the CPU value. If you do not set a `min` value or you set `min` to `0`, the result is no limit and the pod can consume more of the resource than the `max` value.
`Max`	`container.resources.limits[<resource>]` (required) less than or equal to `Max[<resource>]` If the configuration defines a `max` CPU, you do not need to define a CPU request value. However, you must set a limit that satisfies the maximum CPU constraint that is specified in the limit range.
`MaxLimitRequestRatio`	`MaxLimitRequestRatio[<resource>]` less than or equal to (`container.resources.limits[<resource>]` / `container.resources.requests[<resource>]`) If the limit range defines a `maxLimitRequestRatio` constraint, any new containers must have both a `request` and a `limit` value. Additionally, OpenShift Container Platform calculates a limit-to-request ratio by dividing the `limit` by the `request`. The result should be an integer greater than 1. For example, if a container has `cpu: 500` in the `limit` value, and `cpu: 100` in the `request` value, the limit-to-request ratio for `cpu` is `5`. This ratio must be less than or equal to the `maxLimitRequestRatio`.

Min

Min[<resource>] less than or equal to container.resources.requests[<resource>] (required) less than or equal to container/resources.limits[<resource>] (optional)

If the configuration defines a min CPU, the request value must be greater than the CPU value. If you do not set a min value or you set min to 0, the result is no limit and the pod can consume more of the resource than the max value.

Max

container.resources.limits[<resource>] (required) less than or equal to Max[<resource>]

If the configuration defines a max CPU, you do not need to define a CPU request value. However, you must set a limit that satisfies the maximum CPU constraint that is specified in the limit range.

MaxLimitRequestRatio

MaxLimitRequestRatio[<resource>] less than or equal to (container.resources.limits[<resource>] / container.resources.requests[<resource>])

If the limit range defines a maxLimitRequestRatio constraint, any new containers must have both a request and a limit value. Additionally, OpenShift Container Platform calculates a limit-to-request ratio by dividing the limit by the request. The result should be an integer greater than 1.

For example, if a container has cpu: 500 in the limit value, and cpu: 100 in the request value, the limit-to-request ratio for cpu is 5. This ratio must be less than or equal to the maxLimitRequestRatio.

Supported Defaults:

Default[<resource>]: Defaults container.resources.limit[<resource>] to specified value if none.
Default Requests[<resource>]: Defaults container.resources.requests[<resource>] to specified value if none.

5.3.2. Pod limits

Supported Resources:

CPU
Memory

Supported Constraints:

Across all containers in a pod, the following must hold true:

Table 5.4. Pod
Constraint	Enforced Behavior
`Min`	`Min[<resource>]` less than or equal to `container.resources.requests[<resource>]` (required) less than or equal to `container.resources.limits[<resource>]`. If you do not set a `min` value or you set `min` to `0`, the result is no limit and the pod can consume more of the resource than the `max` value.
`Max`	`container.resources.limits[<resource>]` (required) less than or equal to `Max[<resource>]`.
`MaxLimitRequestRatio`	`MaxLimitRequestRatio[<resource>]` less than or equal to (`container.resources.limits[<resource>]` / `container.resources.requests[<resource>]`).

5.3.3. Image limits

Supported Resources:

Storage

Resource type name:

openshift.io/Image

Per image, the following must hold true if specified:

Table 5.5. Image
Constraint	Behavior
`Max`	`image.dockerimagemetadata.size` less than or equal to `Max[<resource>]`

Note

To prevent blobs that exceed the limit from being uploaded to the registry, the registry must be configured to enforce quota. The REGISTRY_MIDDLEWARE_REPOSITORY_OPENSHIFT_ENFORCEQUOTA environment variable must be set to true. By default, the environment variable is set to true for new deployments.

5.3.4. Image stream limits

Supported Resources:

openshift.io/image-tags
openshift.io/images

Resource type name:

openshift.io/ImageStream

Per image stream, the following must hold true if specified:

Table 5.6. ImageStream
Constraint	Behavior
`Max[openshift.io/image-tags]`	`length( uniqueimagetags( imagestream.spec.tags ) )` less than or equal to `Max[openshift.io/image-tags]` `uniqueimagetags` returns unique references to images of given spec tags.
`Max[openshift.io/images]`	`length( uniqueimages( imagestream.status.tags ) )` less than or equal to `Max[openshift.io/images]` `uniqueimages` returns unique image names found in status tags. The name is equal to the digest for the image.

5.3.5. Counting of image references

The openshift.io/image-tags resource represents unique stream limits. Possible references are an ImageStreamTag, an ImageStreamImage, or a DockerImage. Tags can be created by using the oc tag and oc import-image commands or by using image streams. No distinction is made between internal and external references. However, each unique reference that is tagged in an image stream specification is counted just once. It does not restrict pushes to an internal container image registry in any way, but is useful for tag restriction.

The openshift.io/images resource represents unique image names that are recorded in image stream status. It helps to restrict several images that can be pushed to the internal registry. Internal and external references are not distinguished.

5.3.6. PersistentVolumeClaim limits

Supported Resources:

Storage

Supported Constraints:

Across all persistent volume claims in a project, the following must hold true:

Table 5.7. Pod
Constraint	Enforced Behavior
`Min`	Min[<resource>] <= claim.spec.resources.requests[<resource>] (required)
`Max`	claim.spec.resources.requests[<resource>] (required) <= Max[<resource>]

Limit Range Object Definition

{
  "apiVersion": "v1",
  "kind": "LimitRange",
  "metadata": {
    "name": "pvcs" 1
  },
  "spec": {
    "limits": [{
        "type": "PersistentVolumeClaim",
        "min": {
          "storage": "2Gi" 2
        },
        "max": {
          "storage": "50Gi" 3
        }
      }
    ]
  }
}

1: The name of the limit range object.
2: The minimum amount of storage that can be requested in a persistent volume claim.
3: The maximum amount of storage that can be requested in a persistent volume claim.

Additional resources

For information on stream limits, see managing images streams.

For information on stream limits.

For more information on compute resource constraints.

For more information on how CPU and memory are measured, see Recommended control plane practices.

You can specify limits and requests for ephemeral storage. For more information on this feature, see Understanding ephemeral storage.

5.4. Limit range operations

5.4.1. Creating a limit range

Shown here is an example procedure to follow for creating a limit range.

Procedure

Create the object:

$ oc create -f <limit_range_file> -n <project>

5.4.2. View the limit

You can view any limit ranges that are defined in a project by navigating in the web console to the Quota page for the project. You can also use the CLI to view limit range details by performing the following steps:

Procedure

Get the list of limit range objects that are defined in the project. For example, a project called demoproject:
```
$ oc get limits -n demoproject
```
Example Output
```
NAME              AGE
resource-limits   6d
```

Describe the limit range. For example, for a limit range called resource-limits:

$ oc describe limits resource-limits -n demoproject

Example Output

Name:                           resource-limits
Namespace:                      demoproject
Type                            Resource                Min     Max     Default Request Default Limit   Max Limit/Request Ratio
----                            --------                ---     ---     --------------- -------------   -----------------------
Pod                             cpu                     200m    2       -               -               -
Pod                             memory                  6Mi     1Gi     -               -               -
Container                       cpu                     100m    2       200m            300m            10
Container                       memory                  4Mi     1Gi     100Mi           200Mi           -
openshift.io/Image              storage                 -       1Gi     -               -               -
openshift.io/ImageStream        openshift.io/image      -       12      -               -               -
openshift.io/ImageStream        openshift.io/image-tags -       10      -               -               -

5.4.3. Deleting a limit range

To remove a limit range, run the following command:

$ oc delete limits <limit_name>

Additional resources

For information about enforcing different limits on the number of projects that your users can create, managing limits, and quota on project resources, see Resource quotas per projects.

Chapter 6. Recommended host practices for IBM Z & IBM LinuxONE environments

This topic provides recommended host practices for OpenShift Container Platform on IBM Z® and IBM® LinuxONE.

Note

The s390x architecture is unique in many aspects. Therefore, some recommendations made here might not apply to other platforms.

Note

Unless stated otherwise, these practices apply to both z/VM and Red Hat Enterprise Linux (RHEL) KVM installations on IBM Z® and IBM® LinuxONE.

6.1. Managing CPU overcommitment

In a highly virtualized IBM Z® environment, you must carefully plan the infrastructure setup and sizing. One of the most important features of virtualization is the capability to do resource overcommitment, allocating more resources to the virtual machines than actually available at the hypervisor level. This is very workload dependent and there is no golden rule that can be applied to all setups.

Depending on your setup, consider these best practices regarding CPU overcommitment:

At LPAR level (PR/SM hypervisor), avoid assigning all available physical cores (IFLs) to each LPAR. For example, with four physical IFLs available, you should not define three LPARs with four logical IFLs each.
Check and understand LPAR shares and weights.
An excessive number of virtual CPUs can adversely affect performance. Do not define more virtual processors to a guest than logical processors are defined to the LPAR.
Configure the number of virtual processors per guest for peak workload, not more.
Start small and monitor the workload. Increase the vCPU number incrementally if necessary.
Not all workloads are suitable for high overcommitment ratios. If the workload is CPU intensive, you will probably not be able to achieve high ratios without performance problems. Workloads that are more I/O intensive can keep consistent performance even with high overcommitment ratios.

Additional resources

6.2. Disable Transparent Huge Pages

Transparent Huge Pages (THP) attempt to automate most aspects of creating, managing, and using huge pages. Since THP automatically manages the huge pages, this is not always handled optimally for all types of workloads. THP can lead to performance regressions, since many applications handle huge pages on their own. Therefore, consider disabling THP.

6.3. Boost networking performance with Receive Flow Steering

Receive Flow Steering (RFS) extends Receive Packet Steering (RPS) by further reducing network latency. RFS is technically based on RPS, and improves the efficiency of packet processing by increasing the CPU cache hit rate. RFS achieves this, and in addition considers queue length, by determining the most convenient CPU for computation so that cache hits are more likely to occur within the CPU. Thus, the CPU cache is invalidated less and requires fewer cycles to rebuild the cache. This can help reduce packet processing run time.

6.3.1. Use the Machine Config Operator (MCO) to activate RFS

Procedure

Copy the following MCO sample profile into a YAML file. For example, enable-rfs.yaml:

apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: worker
  name: 50-enable-rfs
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
      - contents:
          source: data:text/plain;charset=US-ASCII,%23%20turn%20on%20Receive%20Flow%20Steering%20%28RFS%29%20for%20all%20network%20interfaces%0ASUBSYSTEM%3D%3D%22net%22%2C%20ACTION%3D%3D%22add%22%2C%20RUN%7Bprogram%7D%2B%3D%22/bin/bash%20-c%20%27for%20x%20in%20/sys/%24DEVPATH/queues/rx-%2A%3B%20do%20echo%208192%20%3E%20%24x/rps_flow_cnt%3B%20%20done%27%22%0A
        filesystem: root
        mode: 0644
        path: /etc/udev/rules.d/70-persistent-net.rules
      - contents:
          source: data:text/plain;charset=US-ASCII,%23%20define%20sock%20flow%20enbtried%20for%20%20Receive%20Flow%20Steering%20%28RFS%29%0Anet.core.rps_sock_flow_entries%3D8192%0A
        filesystem: root
        mode: 0644
        path: /etc/sysctl.d/95-enable-rps.conf

Create the MCO profile:
```
$ oc create -f enable-rfs.yaml
```
Verify that an entry named 50-enable-rfs is listed:
```
$ oc get mc
```
To deactivate, enter:
```
$ oc delete mc 50-enable-rfs
```

Additional resources

6.4. Choose your networking setup

The networking stack is one of the most important components for a Kubernetes-based product like OpenShift Container Platform. For IBM Z® setups, the networking setup depends on the hypervisor of your choice. Depending on the workload and the application, the best fit usually changes with the use case and the traffic pattern.

Depending on your setup, consider these best practices:

Consider all options regarding networking devices to optimize your traffic pattern. Explore the advantages of OSA-Express, RoCE Express, HiperSockets, z/VM VSwitch, Linux Bridge (KVM), and others to decide which option leads to the greatest benefit for your setup.
Always use the latest available NIC version. For example, OSA Express 7S 10 GbE shows great improvement compared to OSA Express 6S 10 GbE with transactional workload types, although both are 10 GbE adapters.
Each virtual switch adds an additional layer of latency.
The load balancer plays an important role for network communication outside the cluster. Consider using a production-grade hardware load balancer if this is critical for your application.
OpenShift Container Platform SDN introduces flows and rules, which impact the networking performance. Make sure to consider pod affinities and placements, to benefit from the locality of services where communication is critical.
Balance the trade-off between performance and functionality.

Additional resources

6.5. Ensure high disk performance with HyperPAV on z/VM

DASD and ECKD devices are commonly used disk types in IBM Z® environments. In a typical OpenShift Container Platform setup in z/VM environments, DASD disks are commonly used to support the local storage for the nodes. You can set up HyperPAV alias devices to provide more throughput and overall better I/O performance for the DASD disks that support the z/VM guests.

Using HyperPAV for the local storage devices leads to a significant performance benefit. However, you must be aware that there is a trade-off between throughput and CPU costs.

6.5.1. Use the Machine Config Operator (MCO) to activate HyperPAV aliases in nodes using z/VM full-pack minidisks

For z/VM-based OpenShift Container Platform setups that use full-pack minidisks, you can leverage the advantage of MCO profiles by activating HyperPAV aliases in all of the nodes. You must add YAML configurations for both control plane and compute nodes.

Procedure

Copy the following MCO sample profile into a YAML file for the control plane node. For example, 05-master-kernelarg-hpav.yaml:

$ cat 05-master-kernelarg-hpav.yaml
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: master
  name: 05-master-kernelarg-hpav
spec:
  config:
    ignition:
      version: 3.1.0
  kernelArguments:
    - rd.dasd=800-805

Copy the following MCO sample profile into a YAML file for the compute node. For example, 05-worker-kernelarg-hpav.yaml:

$ cat 05-worker-kernelarg-hpav.yaml
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: worker
  name: 05-worker-kernelarg-hpav
spec:
  config:
    ignition:
      version: 3.1.0
  kernelArguments:
    - rd.dasd=800-805

Note

You must modify the rd.dasd arguments to fit the device IDs.

Create the MCO profiles:

$ oc create -f 05-master-kernelarg-hpav.yaml

$ oc create -f 05-worker-kernelarg-hpav.yaml

To deactivate, enter:

$ oc delete -f 05-master-kernelarg-hpav.yaml

$ oc delete -f 05-worker-kernelarg-hpav.yaml

Additional resources

6.6. RHEL KVM on IBM Z host recommendations

Optimizing a KVM virtual server environment strongly depends on the workloads of the virtual servers and on the available resources. The same action that enhances performance in one environment can have adverse effects in another. Finding the best balance for a particular setting can be a challenge and often involves experimentation.

The following section introduces some best practices when using OpenShift Container Platform with RHEL KVM on IBM Z® and IBM® LinuxONE environments.

6.6.1. Use I/O threads for your virtual block devices

To make virtual block devices use I/O threads, you must configure one or more I/O threads for the virtual server and each virtual block device to use one of these I/O threads.

The following example specifies <iothreads>3</iothreads> to configure three I/O threads, with consecutive decimal thread IDs 1, 2, and 3. The iothread="2" parameter specifies the driver element of the disk device to use the I/O thread with ID 2.

Sample I/O thread specification

...
<domain>
 	<iothreads>3</iothreads>1
  	 ...
    	<devices>
       ...
          <disk type="block" device="disk">2
<driver ... iothread="2"/>
    </disk>
       ...
    	</devices>
   ...
</domain>

1: The number of I/O threads.
2: The driver element of the disk device.

Threads can increase the performance of I/O operations for disk devices, but they also use memory and CPU resources. You can configure multiple devices to use the same thread. The best mapping of threads to devices depends on the available resources and the workload.

Start with a small number of I/O threads. Often, a single I/O thread for all disk devices is sufficient. Do not configure more threads than the number of virtual CPUs, and do not configure idle threads.

You can use the virsh iothreadadd command to add I/O threads with specific thread IDs to a running virtual server.

6.6.2. Avoid virtual SCSI devices

Configure virtual SCSI devices only if you need to address the device through SCSI-specific interfaces. Configure disk space as virtual block devices rather than virtual SCSI devices, regardless of the backing on the host.

However, you might need SCSI-specific interfaces for:

A LUN for a SCSI-attached tape drive on the host.
A DVD ISO file on the host file system that is mounted on a virtual DVD drive.

6.6.3. Configure guest caching for disk

Configure your disk devices to do caching by the guest and not by the host.

Ensure that the driver element of the disk device includes the cache="none" and io="native" parameters.

<disk type="block" device="disk">
    <driver name="qemu" type="raw" cache="none" io="native" iothread="1"/>
...
</disk>

6.6.4. Exclude the memory balloon device

Unless you need a dynamic memory size, do not define a memory balloon device and ensure that libvirt does not create one for you. Include the memballoon parameter as a child of the devices element in your domain configuration XML file.

Check the list of active profiles:
```
<memballoon model="none"/>
```

6.6.5. Tune the CPU migration algorithm of the host scheduler

Important

Do not change the scheduler settings unless you are an expert who understands the implications. Do not apply changes to production systems without testing them and confirming that they have the intended effect.

The kernel.sched_migration_cost_ns parameter specifies a time interval in nanoseconds. After the last execution of a task, the CPU cache is considered to have useful content until this interval expires. Increasing this interval results in fewer task migrations. The default value is 500000 ns.

If the CPU idle time is higher than expected when there are runnable processes, try reducing this interval. If tasks bounce between CPUs or nodes too often, try increasing it.

To dynamically set the interval to 60000 ns, enter the following command:

# sysctl kernel.sched_migration_cost_ns=60000

To persistently change the value to 60000 ns, add the following entry to /etc/sysctl.conf:

kernel.sched_migration_cost_ns=60000

6.6.6. Disable the cpuset cgroup controller

Note

This setting applies only to KVM hosts with cgroups version 1. To enable CPU hotplug on the host, disable the cgroup controller.

Procedure

Open /etc/libvirt/qemu.conf with an editor of your choice.
Go to the cgroup_controllers line.
Duplicate the entire line and remove the leading number sign (#) from the copy.

Remove the cpuset entry, as follows:

cgroup_controllers = [ "cpu", "devices", "memory", "blkio", "cpuacct" ]

For the new setting to take effect, you must restart the libvirtd daemon:
1. Stop all virtual machines.
2. Run the following command:
```
# systemctl restart libvirtd
```
3. Restart the virtual machines.

This setting persists across host reboots.

6.6.7. Tune the polling period for idle virtual CPUs

When a virtual CPU becomes idle, KVM polls for wakeup conditions for the virtual CPU before allocating the host resource. You can specify the time interval, during which polling takes place in sysfs at /sys/module/kvm/parameters/halt_poll_ns. During the specified time, polling reduces the wakeup latency for the virtual CPU at the expense of resource usage. Depending on the workload, a longer or shorter time for polling can be beneficial. The time interval is specified in nanoseconds. The default is 50000 ns.

To optimize for low CPU consumption, enter a small value or write 0 to disable polling:
```
# echo 0 > /sys/module/kvm/parameters/halt_poll_ns
```
To optimize for low latency, for example for transactional workloads, enter a large value:
```
# echo 80000 > /sys/module/kvm/parameters/halt_poll_ns
```

Additional resources

Chapter 7. Using the Node Tuning Operator

Learn about the Node Tuning Operator and how you can use it to manage node-level tuning by orchestrating the tuned daemon.

7.1. About the Node Tuning Operator

The Node Tuning Operator helps you manage node-level tuning by orchestrating the TuneD daemon and achieves low latency performance by using the Performance Profile controller. The majority of high-performance applications require some level of kernel tuning. The Node Tuning Operator provides a unified management interface to users of node-level sysctls and more flexibility to add custom tuning specified by user needs.

The Operator manages the containerized TuneD daemon for OpenShift Container Platform as a Kubernetes daemon set. It ensures the custom tuning specification is passed to all containerized TuneD daemons running in the cluster in the format that the daemons understand. The daemons run on all nodes in the cluster, one per node.

Node-level settings applied by the containerized TuneD daemon are rolled back on an event that triggers a profile change or when the containerized TuneD daemon is terminated gracefully by receiving and handling a termination signal.

The Node Tuning Operator uses the Performance Profile controller to implement automatic tuning to achieve low latency performance for OpenShift Container Platform applications.

The cluster administrator configures a performance profile to define node-level settings such as the following:

Updating the kernel to kernel-rt.
Choosing CPUs for housekeeping.
Choosing CPUs for running workloads.

Note

Currently, disabling CPU load balancing is not supported by cgroup v2. As a result, you might not get the desired behavior from performance profiles if you have cgroup v2 enabled. Enabling cgroup v2 is not recommended if you are using performance profiles.

The Node Tuning Operator is part of a standard OpenShift Container Platform installation in version 4.1 and later.

Note

In earlier versions of OpenShift Container Platform, the Performance Addon Operator was used to implement automatic tuning to achieve low latency performance for OpenShift applications. In OpenShift Container Platform 4.11 and later, this functionality is part of the Node Tuning Operator.

7.2. Accessing an example Node Tuning Operator specification

Use this process to access an example Node Tuning Operator specification.

Procedure

Run the following command to access an example Node Tuning Operator specification:

oc get tuned.tuned.openshift.io/default -o yaml -n openshift-cluster-node-tuning-operator

The default CR is meant for delivering standard node-level tuning for the OpenShift Container Platform platform and it can only be modified to set the Operator Management state. Any other custom changes to the default CR will be overwritten by the Operator. For custom tuning, create your own Tuned CRs. Newly created CRs will be combined with the default CR and custom tuning applied to OpenShift Container Platform nodes based on node or pod labels and profile priorities.

Warning

While in certain situations the support for pod labels can be a convenient way of automatically delivering required tuning, this practice is discouraged and strongly advised against, especially in large-scale clusters. The default Tuned CR ships without pod label matching. If a custom profile is created with pod label matching, then the functionality will be enabled at that time. The pod label functionality will be deprecated in future versions of the Node Tuning Operator.

7.3. Default profiles set on a cluster

The following are the default profiles set on a cluster.

apiVersion: tuned.openshift.io/v1
kind: Tuned
metadata:
  name: default
  namespace: openshift-cluster-node-tuning-operator
spec:
  profile:
  - data: |
      [main]
      summary=Optimize systems running OpenShift (provider specific parent profile)
      include=-provider-${f:exec:cat:/var/lib/tuned/provider},openshift
    name: openshift
  recommend:
  - profile: openshift-control-plane
    priority: 30
    match:
    - label: node-role.kubernetes.io/master
    - label: node-role.kubernetes.io/infra
  - profile: openshift-node
    priority: 40

Starting with OpenShift Container Platform 4.9, all OpenShift TuneD profiles are shipped with the TuneD package. You can use the oc exec command to view the contents of these profiles:

$ oc exec $tuned_pod -n openshift-cluster-node-tuning-operator -- find /usr/lib/tuned/openshift{,-control-plane,-node} -name tuned.conf -exec grep -H ^ {} \;

7.4. Verifying that the TuneD profiles are applied

Verify the TuneD profiles that are applied to your cluster node.

$ oc get profile.tuned.openshift.io -n openshift-cluster-node-tuning-operator

Example output

NAME             TUNED                     APPLIED   DEGRADED   AGE
master-0         openshift-control-plane   True      False      6h33m
master-1         openshift-control-plane   True      False      6h33m
master-2         openshift-control-plane   True      False      6h33m
worker-a         openshift-node            True      False      6h28m
worker-b         openshift-node            True      False      6h28m

NAME: Name of the Profile object. There is one Profile object per node and their names match.
TUNED: Name of the desired TuneD profile to apply.
APPLIED: True if the TuneD daemon applied the desired profile. (True/False/Unknown).
DEGRADED: True if any errors were reported during application of the TuneD profile (True/False/Unknown).
AGE: Time elapsed since the creation of Profile object.

The ClusterOperator/node-tuning object also contains useful information about the Operator and its node agents' health. For example, Operator misconfiguration is reported by ClusterOperator/node-tuning status messages.

To get status information about the ClusterOperator/node-tuning object, run the following command:

$ oc get co/node-tuning -n openshift-cluster-node-tuning-operator

Example output

NAME          VERSION   AVAILABLE   PROGRESSING   DEGRADED   SINCE   MESSAGE
node-tuning   4.14.1    True        False         True       60m     1/5 Profiles with bootcmdline conflict

If either the ClusterOperator/node-tuning or a profile object’s status is DEGRADED, additional information is provided in the Operator or operand logs.

7.5. Custom tuning specification

The custom resource (CR) for the Operator has two major sections. The first section, profile:, is a list of TuneD profiles and their names. The second, recommend:, defines the profile selection logic.

Multiple custom tuning specifications can co-exist as multiple CRs in the Operator’s namespace. The existence of new CRs or the deletion of old CRs is detected by the Operator. All existing custom tuning specifications are merged and appropriate objects for the containerized TuneD daemons are updated.

Management state

The Operator Management state is set by adjusting the default Tuned CR. By default, the Operator is in the Managed state and the spec.managementState field is not present in the default Tuned CR. Valid values for the Operator Management state are as follows:

Managed: the Operator will update its operands as configuration resources are updated
Unmanaged: the Operator will ignore changes to the configuration resources
Removed: the Operator will remove its operands and resources the Operator provisioned

Profile data

The profile: section lists TuneD profiles and their names.

profile:
- name: tuned_profile_1
  data: |
    # TuneD profile specification
    [main]
    summary=Description of tuned_profile_1 profile

    [sysctl]
    net.ipv4.ip_forward=1
    # ... other sysctl's or other TuneD daemon plugins supported by the containerized TuneD

# ...

- name: tuned_profile_n
  data: |
    # TuneD profile specification
    [main]
    summary=Description of tuned_profile_n profile

    # tuned_profile_n profile settings

Recommended profiles

The profile: selection logic is defined by the recommend: section of the CR. The recommend: section is a list of items to recommend the profiles based on a selection criteria.

recommend:
<recommend-item-1>
# ...
<recommend-item-n>

The individual items of the list:

- machineConfigLabels: 1
    <mcLabels> 2
  match: 3
    <match> 4
  priority: <priority> 5
  profile: <tuned_profile_name> 6
  operand: 7
    debug: <bool> 8
    tunedConfig:
      reapply_sysctl: <bool> 9

1: Optional.
2: A dictionary of key/value MachineConfig labels. The keys must be unique.
3: If omitted, profile match is assumed unless a profile with a higher priority matches first or machineConfigLabels is set.
4: An optional list.
5: Profile ordering priority. Lower numbers mean higher priority (0 is the highest priority).
6: A TuneD profile to apply on a match. For example tuned_profile_1.
7: Optional operand configuration.
8: Turn debugging on or off for the TuneD daemon. Options are true for on or false for off. The default is false.
9: Turn reapply_sysctl functionality on or off for the TuneD daemon. Options are true for on and false for off.

<match> is an optional list recursively defined as follows:

- label: <label_name> 1
  value: <label_value> 2
  type: <label_type> 3
    <match> 4

1: Node or pod label name.
2: Optional node or pod label value. If omitted, the presence of <label_name> is enough to match.
3: Optional object type (node or pod). If omitted, node is assumed.
4: An optional <match> list.

If <match> is not omitted, all nested <match> sections must also evaluate to true. Otherwise, false is assumed and the profile with the respective <match> section will not be applied or recommended. Therefore, the nesting (child <match> sections) works as logical AND operator. Conversely, if any item of the <match> list matches, the entire <match> list evaluates to true. Therefore, the list acts as logical OR operator.

If machineConfigLabels is defined, machine config pool based matching is turned on for the given recommend: list item. <mcLabels> specifies the labels for a machine config. The machine config is created automatically to apply host settings, such as kernel boot parameters, for the profile <tuned_profile_name>. This involves finding all machine config pools with machine config selector matching <mcLabels> and setting the profile <tuned_profile_name> on all nodes that are assigned the found machine config pools. To target nodes that have both master and worker roles, you must use the master role.

The list items match and machineConfigLabels are connected by the logical OR operator. The match item is evaluated first in a short-circuit manner. Therefore, if it evaluates to true, the machineConfigLabels item is not considered.

Important

When using machine config pool based matching, it is advised to group nodes with the same hardware configuration into the same machine config pool. Not following this practice might result in TuneD operands calculating conflicting kernel parameters for two or more nodes sharing the same machine config pool.

Example: Node or pod label based matching

- match:
  - label: tuned.openshift.io/elasticsearch
    match:
    - label: node-role.kubernetes.io/master
    - label: node-role.kubernetes.io/infra
    type: pod
  priority: 10
  profile: openshift-control-plane-es
- match:
  - label: node-role.kubernetes.io/master
  - label: node-role.kubernetes.io/infra
  priority: 20
  profile: openshift-control-plane
- priority: 30
  profile: openshift-node

The CR above is translated for the containerized TuneD daemon into its recommend.conf file based on the profile priorities. The profile with the highest priority (10) is openshift-control-plane-es and, therefore, it is considered first. The containerized TuneD daemon running on a given node looks to see if there is a pod running on the same node with the tuned.openshift.io/elasticsearch label set. If not, the entire <match> section evaluates as false. If there is such a pod with the label, in order for the <match> section to evaluate to true, the node label also needs to be node-role.kubernetes.io/master or node-role.kubernetes.io/infra.

If the labels for the profile with priority 10 matched, openshift-control-plane-es profile is applied and no other profile is considered. If the node/pod label combination did not match, the second highest priority profile (openshift-control-plane) is considered. This profile is applied if the containerized TuneD pod runs on a node with labels node-role.kubernetes.io/master or node-role.kubernetes.io/infra.

Finally, the profile openshift-node has the lowest priority of 30. It lacks the <match> section and, therefore, will always match. It acts as a profile catch-all to set openshift-node profile, if no other profile with higher priority matches on a given node.

Example: Machine config pool based matching

apiVersion: tuned.openshift.io/v1
kind: Tuned
metadata:
  name: openshift-node-custom
  namespace: openshift-cluster-node-tuning-operator
spec:
  profile:
  - data: |
      [main]
      summary=Custom OpenShift node profile with an additional kernel parameter
      include=openshift-node
      [bootloader]
      cmdline_openshift_node_custom=+skew_tick=1
    name: openshift-node-custom

  recommend:
  - machineConfigLabels:
      machineconfiguration.openshift.io/role: "worker-custom"
    priority: 20
    profile: openshift-node-custom

To minimize node reboots, label the target nodes with a label the machine config pool’s node selector will match, then create the Tuned CR above and finally create the custom machine config pool itself.

Cloud provider-specific TuneD profiles

With this functionality, all Cloud provider-specific nodes can conveniently be assigned a TuneD profile specifically tailored to a given Cloud provider on a OpenShift Container Platform cluster. This can be accomplished without adding additional node labels or grouping nodes into machine config pools.

This functionality takes advantage of spec.providerID node object values in the form of <cloud-provider>://<cloud-provider-specific-id> and writes the file /var/lib/tuned/provider with the value <cloud-provider> in NTO operand containers. The content of this file is then used by TuneD to load provider-<cloud-provider> profile if such profile exists.

The openshift profile that both openshift-control-plane and openshift-node profiles inherit settings from is now updated to use this functionality through the use of conditional profile loading. Neither NTO nor TuneD currently include any Cloud provider-specific profiles. However, it is possible to create a custom profile provider-<cloud-provider> that will be applied to all Cloud provider-specific cluster nodes.

Example GCE Cloud provider profile

apiVersion: tuned.openshift.io/v1
kind: Tuned
metadata:
  name: provider-gce
  namespace: openshift-cluster-node-tuning-operator
spec:
  profile:
  - data: |
      [main]
      summary=GCE Cloud provider-specific profile
      # Your tuning for GCE Cloud provider goes here.
    name: provider-gce

Note

Due to profile inheritance, any setting specified in the provider-<cloud-provider> profile will be overwritten by the openshift profile and its child profiles.

7.6. Custom tuning examples

Using TuneD profiles from the default CR

The following CR applies custom node-level tuning for OpenShift Container Platform nodes with label tuned.openshift.io/ingress-node-label set to any value.

Example: custom tuning using the openshift-control-plane TuneD profile

apiVersion: tuned.openshift.io/v1
kind: Tuned
metadata:
  name: ingress
  namespace: openshift-cluster-node-tuning-operator
spec:
  profile:
  - data: |
      [main]
      summary=A custom OpenShift ingress profile
      include=openshift-control-plane
      [sysctl]
      net.ipv4.ip_local_port_range="1024 65535"
      net.ipv4.tcp_tw_reuse=1
    name: openshift-ingress
  recommend:
  - match:
    - label: tuned.openshift.io/ingress-node-label
    priority: 10
    profile: openshift-ingress

Important

Custom profile writers are strongly encouraged to include the default TuneD daemon profiles shipped within the default Tuned CR. The example above uses the default openshift-control-plane profile to accomplish this.

Using built-in TuneD profiles

Given the successful rollout of the NTO-managed daemon set, the TuneD operands all manage the same version of the TuneD daemon. To list the built-in TuneD profiles supported by the daemon, query any TuneD pod in the following way:

$ oc exec $tuned_pod -n openshift-cluster-node-tuning-operator -- find /usr/lib/tuned/ -name tuned.conf -printf '%h\n' | sed 's|^.*/||'

You can use the profile names retrieved by this in your custom tuning specification.

Example: using built-in hpc-compute TuneD profile

apiVersion: tuned.openshift.io/v1
kind: Tuned
metadata:
  name: openshift-node-hpc-compute
  namespace: openshift-cluster-node-tuning-operator
spec:
  profile:
  - data: |
      [main]
      summary=Custom OpenShift node profile for HPC compute workloads
      include=openshift-node,hpc-compute
    name: openshift-node-hpc-compute

  recommend:
  - match:
    - label: tuned.openshift.io/openshift-node-hpc-compute
    priority: 20
    profile: openshift-node-hpc-compute

In addition to the built-in hpc-compute profile, the example above includes the openshift-node TuneD daemon profile shipped within the default Tuned CR to use OpenShift-specific tuning for compute nodes.

Overriding host-level sysctls

Various kernel parameters can be changed at runtime by using /run/sysctl.d/, /etc/sysctl.d/, and /etc/sysctl.conf host configuration files. OpenShift Container Platform adds several host configuration files which set kernel parameters at runtime; for example, net.ipv[4-6]., fs.inotify., and vm.max_map_count. These runtime parameters provide basic functional tuning for the system prior to the kubelet and the Operator start.

The Operator does not override these settings unless the reapply_sysctl option is set to false. Setting this option to false results in TuneD not applying the settings from the host configuration files after it applies its custom profile.

Example: overriding host-level sysctls

apiVersion: tuned.openshift.io/v1
kind: Tuned
metadata:
  name: openshift-no-reapply-sysctl
  namespace: openshift-cluster-node-tuning-operator
spec:
  profile:
  - data: |
      [main]
      summary=Custom OpenShift profile
      include=openshift-node
      [sysctl]
      vm.max_map_count=>524288
    name: openshift-no-reapply-sysctl
  recommend:
  - match:
    - label: tuned.openshift.io/openshift-no-reapply-sysctl
    priority: 15
    profile: openshift-no-reapply-sysctl
    operand:
      tunedConfig:
        reapply_sysctl: false

7.7. Supported TuneD daemon plugins

Excluding the [main] section, the following TuneD plugins are supported when using custom profiles defined in the profile: section of the Tuned CR:

audio
cpu
disk
eeepc_she
modules
mounts
net
scheduler
scsi_host
selinux
sysctl
sysfs
usb
video
vm
bootloader

There is some dynamic tuning functionality provided by some of these plugins that is not supported. The following TuneD plugins are currently not supported:

script
systemd

Note

The TuneD bootloader plugin only supports Red Hat Enterprise Linux CoreOS (RHCOS) worker nodes.

Additional resources

7.8. Configuring node tuning in a hosted cluster

To set node-level tuning on the nodes in your hosted cluster, you can use the Node Tuning Operator. In hosted control planes, you can configure node tuning by creating config maps that contain Tuned objects and referencing those config maps in your node pools.

Procedure

Create a config map that contains a valid tuned manifest, and reference the manifest in a node pool. In the following example, a Tuned manifest defines a profile that sets vm.dirty_ratio to 55 on nodes that contain the tuned-1-node-label node label with any value. Save the following ConfigMap manifest in a file named tuned-1.yaml:
```
    apiVersion: v1
    kind: ConfigMap
    metadata:
      name: tuned-1
      namespace: clusters
    data:
      tuning: |
        apiVersion: tuned.openshift.io/v1
        kind: Tuned
        metadata:
          name: tuned-1
          namespace: openshift-cluster-node-tuning-operator
        spec:
          profile:
          - data: |
              [main]
              summary=Custom OpenShift profile
              include=openshift-node
              [sysctl]
              vm.dirty_ratio="55"
            name: tuned-1-profile
          recommend:
          - priority: 20
            profile: tuned-1-profile
```
Note
If you do not add any labels to an entry in the spec.recommend section of the Tuned spec, node-pool-based matching is assumed, so the highest priority profile in the spec.recommend section is applied to nodes in the pool. Although you can achieve more fine-grained node-label-based matching by setting a label value in the Tuned .spec.recommend.match section, node labels will not persist during an upgrade unless you set the .spec.management.upgradeType value of the node pool to InPlace.

Create the ConfigMap object in the management cluster:

$ oc --kubeconfig="$MGMT_KUBECONFIG" create -f tuned-1.yaml

Reference the ConfigMap object in the spec.tuningConfig field of the node pool, either by editing a node pool or creating one. In this example, assume that you have only one NodePool, named nodepool-1, which contains 2 nodes.
```
    apiVersion: hypershift.openshift.io/v1alpha1
    kind: NodePool
    metadata:
      ...
      name: nodepool-1
      namespace: clusters
    ...
    spec:
      ...
      tuningConfig:
      - name: tuned-1
    status:
    ...
```
Note
You can reference the same config map in multiple node pools. In hosted control planes, the Node Tuning Operator appends a hash of the node pool name and namespace to the name of the Tuned CRs to distinguish them. Outside of this case, do not create multiple TuneD profiles of the same name in different Tuned CRs for the same hosted cluster.

Verification

Now that you have created the ConfigMap object that contains a Tuned manifest and referenced it in a NodePool, the Node Tuning Operator syncs the Tuned objects into the hosted cluster. You can verify which Tuned objects are defined and which TuneD profiles are applied to each node.

List the Tuned objects in the hosted cluster:

$ oc --kubeconfig="$HC_KUBECONFIG" get tuned.tuned.openshift.io -n openshift-cluster-node-tuning-operator

Example output

NAME       AGE
default    7m36s
rendered   7m36s
tuned-1    65s

List the Profile objects in the hosted cluster:

$ oc --kubeconfig="$HC_KUBECONFIG" get profile.tuned.openshift.io -n openshift-cluster-node-tuning-operator

Example output

NAME                           TUNED            APPLIED   DEGRADED   AGE
nodepool-1-worker-1            tuned-1-profile  True      False      7m43s
nodepool-1-worker-2            tuned-1-profile  True      False      7m14s

Note

If no custom profiles are created, the openshift-node profile is applied by default.

To confirm that the tuning was applied correctly, start a debug shell on a node and check the sysctl values:

$ oc --kubeconfig="$HC_KUBECONFIG" debug node/nodepool-1-worker-1 -- chroot /host sysctl vm.dirty_ratio

Example output

vm.dirty_ratio = 55

7.9. Advanced node tuning for hosted clusters by setting kernel boot parameters

For more advanced tuning in hosted control planes, which requires setting kernel boot parameters, you can also use the Node Tuning Operator. The following example shows how you can create a node pool with huge pages reserved.

Procedure

Create a ConfigMap object that contains a Tuned object manifest for creating 10 huge pages that are 2 MB in size. Save this ConfigMap manifest in a file named tuned-hugepages.yaml:

    apiVersion: v1
    kind: ConfigMap
    metadata:
      name: tuned-hugepages
      namespace: clusters
    data:
      tuning: |
        apiVersion: tuned.openshift.io/v1
        kind: Tuned
        metadata:
          name: hugepages
          namespace: openshift-cluster-node-tuning-operator
        spec:
          profile:
          - data: |
              [main]
              summary=Boot time configuration for hugepages
              include=openshift-node
              [bootloader]
              cmdline_openshift_node_hugepages=hugepagesz=2M hugepages=50
            name: openshift-node-hugepages
          recommend:
          - priority: 20
            profile: openshift-node-hugepages

Note

The .spec.recommend.match field is intentionally left blank. In this case, this Tuned object is applied to all nodes in the node pool where this ConfigMap object is referenced. Group nodes with the same hardware configuration into the same node pool. Otherwise, TuneD operands can calculate conflicting kernel parameters for two or more nodes that share the same node pool.

Create the ConfigMap object in the management cluster:
```
$ oc --kubeconfig="<management_cluster_kubeconfig>" create -f tuned-hugepages.yaml 1
```
1
Replace <management_cluster_kubeconfig> with the name of your management cluster kubeconfig file.
Create a NodePool manifest YAML file, customize the upgrade type of the NodePool, and reference the ConfigMap object that you created in the spec.tuningConfig section. Create the NodePool manifest and save it in a file named hugepages-nodepool.yaml by using the hcp CLI:
```
$ hcp create nodepool aws \
  --cluster-name <hosted_cluster_name> \1
  --name <nodepool_name> \2
  --node-count <nodepool_replicas> \3
  --instance-type <instance_type> \4
  --render > hugepages-nodepool.yaml
```
1
Replace <hosted_cluster_name> with the name of your hosted cluster.
2
Replace <nodepool_name> with the name of your node pool.
3
Replace <nodepool_replicas> with the number of your node pool replicas, for example, 2.
4
Replace <instance_type> with the instance type, for example, m5.2xlarge.
Note
The --render flag in the hcp create command does not render the secrets. To render the secrets, you must use both the --render and the --render-sensitive flags in the hcp create command.
In the hugepages-nodepool.yaml file, set .spec.management.upgradeType to InPlace, and set .spec.tuningConfig to reference the tuned-hugepages ConfigMap object that you created.
```
    apiVersion: hypershift.openshift.io/v1alpha1
    kind: NodePool
    metadata:
      name: hugepages-nodepool
      namespace: clusters
      ...
    spec:
      management:
        ...
        upgradeType: InPlace
      ...
      tuningConfig:
      - name: tuned-hugepages
```
Note
To avoid the unnecessary re-creation of nodes when you apply the new MachineConfig objects, set .spec.management.upgradeType to InPlace. If you use the Replace upgrade type, nodes are fully deleted and new nodes can replace them when you apply the new kernel boot parameters that the TuneD operand calculated.

Create the NodePool in the management cluster:

$ oc --kubeconfig="<management_cluster_kubeconfig>" create -f hugepages-nodepool.yaml

Verification

After the nodes are available, the containerized TuneD daemon calculates the required kernel boot parameters based on the applied TuneD profile. After the nodes are ready and reboot once to apply the generated MachineConfig object, you can verify that the TuneD profile is applied and that the kernel boot parameters are set.

List the Tuned objects in the hosted cluster:

$ oc --kubeconfig="<hosted_cluster_kubeconfig>" get tuned.tuned.openshift.io -n openshift-cluster-node-tuning-operator

Example output

NAME                 AGE
default              123m
hugepages-8dfb1fed   1m23s
rendered             123m

List the Profile objects in the hosted cluster:

$ oc --kubeconfig="<hosted_cluster_kubeconfig>" get profile.tuned.openshift.io -n openshift-cluster-node-tuning-operator

Example output

NAME                           TUNED                      APPLIED   DEGRADED   AGE
nodepool-1-worker-1            openshift-node             True      False      132m
nodepool-1-worker-2            openshift-node             True      False      131m
hugepages-nodepool-worker-1    openshift-node-hugepages   True      False      4m8s
hugepages-nodepool-worker-2    openshift-node-hugepages   True      False      3m57s

Both of the worker nodes in the new NodePool have the openshift-node-hugepages profile applied.

To confirm that the tuning was applied correctly, start a debug shell on a node and check /proc/cmdline.

$ oc --kubeconfig="<hosted_cluster_kubeconfig>" debug node/nodepool-1-worker-1 -- chroot /host cat /proc/cmdline

Example output

BOOT_IMAGE=(hd0,gpt3)/ostree/rhcos-... hugepagesz=2M hugepages=50

Additional resources

For more information about hosted control planes, see Hosted control planes.

Chapter 8. Using CPU Manager and Topology Manager

CPU Manager manages groups of CPUs and constrains workloads to specific CPUs.

CPU Manager is useful for workloads that have some of these attributes:

Require as much CPU time as possible.
Are sensitive to processor cache misses.
Are low-latency network applications.
Coordinate with other processes and benefit from sharing a single processor cache.

Topology Manager collects hints from the CPU Manager, Device Manager, and other Hint Providers to align pod resources, such as CPU, SR-IOV VFs, and other device resources, for all Quality of Service (QoS) classes on the same non-uniform memory access (NUMA) node.

Topology Manager uses topology information from the collected hints to decide if a pod can be accepted or rejected on a node, based on the configured Topology Manager policy and pod resources requested.

Topology Manager is useful for workloads that use hardware accelerators to support latency-critical execution and high throughput parallel computation.

To use Topology Manager you must configure CPU Manager with the static policy.

8.1. Setting up CPU Manager

Procedure

Optional: Label a node:

# oc label node perf-node.example.com cpumanager=true

Edit the MachineConfigPool of the nodes where CPU Manager should be enabled. In this example, all workers have CPU Manager enabled:
```
# oc edit machineconfigpool worker
```

Add a label to the worker machine config pool:

metadata:
  creationTimestamp: 2020-xx-xxx
  generation: 3
  labels:
    custom-kubelet: cpumanager-enabled

Create a KubeletConfig, cpumanager-kubeletconfig.yaml, custom resource (CR). Refer to the label created in the previous step to have the correct nodes updated with the new kubelet config. See the machineConfigPoolSelector section:
```
apiVersion: machineconfiguration.openshift.io/v1
kind: KubeletConfig
metadata:
  name: cpumanager-enabled
spec:
  machineConfigPoolSelector:
    matchLabels:
      custom-kubelet: cpumanager-enabled
  kubeletConfig:
     cpuManagerPolicy: static 1
     cpuManagerReconcilePeriod: 5s 2
```
1
Specify a policy:
none. This policy explicitly enables the existing default CPU affinity scheme, providing no affinity beyond what the scheduler does automatically. This is the default policy.
static. This policy allows containers in guaranteed pods with integer CPU requests. It also limits access to exclusive CPUs on the node. If static, you must use a lowercase s.
2
Optional. Specify the CPU Manager reconcile frequency. The default is 5s.
Create the dynamic kubelet config:
```
# oc create -f cpumanager-kubeletconfig.yaml
```
This adds the CPU Manager feature to the kubelet config and, if needed, the Machine Config Operator (MCO) reboots the node. To enable CPU Manager, a reboot is not needed.

Check for the merged kubelet config:

# oc get machineconfig 99-worker-XXXXXX-XXXXX-XXXX-XXXXX-kubelet -o json | grep ownerReference -A7

Example output

       "ownerReferences": [
            {
                "apiVersion": "machineconfiguration.openshift.io/v1",
                "kind": "KubeletConfig",
                "name": "cpumanager-enabled",
                "uid": "7ed5616d-6b72-11e9-aae1-021e1ce18878"
            }
        ]

Check the worker for the updated kubelet.conf:
```
# oc debug node/perf-node.example.com
sh-4.2# cat /host/etc/kubernetes/kubelet.conf | grep cpuManager
```
Example output
```
cpuManagerPolicy: static        1
cpuManagerReconcilePeriod: 5s   2
```
1
cpuManagerPolicy is defined when you create the KubeletConfig CR.
2
cpuManagerReconcilePeriod is defined when you create the KubeletConfig CR.

Create a pod that requests a core or multiple cores. Both limits and requests must have their CPU value set to a whole integer. That is the number of cores that will be dedicated to this pod:

# cat cpumanager-pod.yaml

Example output

apiVersion: v1
kind: Pod
metadata:
  generateName: cpumanager-
spec:
  containers:
  - name: cpumanager
    image: gcr.io/google_containers/pause:3.2
    resources:
      requests:
        cpu: 1
        memory: "1G"
      limits:
        cpu: 1
        memory: "1G"
  nodeSelector:
    cpumanager: "true"

Create the pod:
```
# oc create -f cpumanager-pod.yaml
```

Verify that the pod is scheduled to the node that you labeled:

# oc describe pod cpumanager

Example output

Name:               cpumanager-6cqz7
Namespace:          default
Priority:           0
PriorityClassName:  <none>
Node:  perf-node.example.com/xxx.xx.xx.xxx
...
 Limits:
      cpu:     1
      memory:  1G
    Requests:
      cpu:        1
      memory:     1G
...
QoS Class:       Guaranteed
Node-Selectors:  cpumanager=true

Verify that the cgroups are set up correctly. Get the process ID (PID) of the pause process:

# ├─init.scope
│ └─1 /usr/lib/systemd/systemd --switched-root --system --deserialize 17
└─kubepods.slice
  ├─kubepods-pod69c01f8e_6b74_11e9_ac0f_0a2b62178a22.slice
  │ ├─crio-b5437308f1a574c542bdf08563b865c0345c8f8c0b0a655612c.scope
  │ └─32706 /pause

Pods of quality of service (QoS) tier Guaranteed are placed within the kubepods.slice. Pods of other QoS tiers end up in child cgroups of kubepods:

# cd /sys/fs/cgroup/cpuset/kubepods.slice/kubepods-pod69c01f8e_6b74_11e9_ac0f_0a2b62178a22.slice/crio-b5437308f1ad1a7db0574c542bdf08563b865c0345c86e9585f8c0b0a655612c.scope
# for i in `ls cpuset.cpus tasks` ; do echo -n "$i "; cat $i ; done

Example output

cpuset.cpus 1
tasks 32706

Check the allowed CPU list for the task:

# grep ^Cpus_allowed_list /proc/32706/status

Example output

 Cpus_allowed_list:    1

Verify that another pod (in this case, the pod in the burstable QoS tier) on the system cannot run on the core allocated for the Guaranteed pod:

# cat /sys/fs/cgroup/cpuset/kubepods.slice/kubepods-besteffort.slice/kubepods-besteffort-podc494a073_6b77_11e9_98c0_06bba5c387ea.slice/crio-c56982f57b75a2420947f0afc6cafe7534c5734efc34157525fa9abbf99e3849.scope/cpuset.cpus
0
# oc describe node perf-node.example.com

Example output

...
Capacity:
 attachable-volumes-aws-ebs:  39
 cpu:                         2
 ephemeral-storage:           124768236Ki
 hugepages-1Gi:               0
 hugepages-2Mi:               0
 memory:                      8162900Ki
 pods:                        250
Allocatable:
 attachable-volumes-aws-ebs:  39
 cpu:                         1500m
 ephemeral-storage:           124768236Ki
 hugepages-1Gi:               0
 hugepages-2Mi:               0
 memory:                      7548500Ki
 pods:                        250
-------                               ----                           ------------  ----------  ---------------  -------------  ---
  default                                 cpumanager-6cqz7               1 (66%)       1 (66%)     1G (12%)         1G (12%)       29m

Allocated resources:
  (Total limits may be over 100 percent, i.e., overcommitted.)
  Resource                    Requests          Limits
  --------                    --------          ------
  cpu                         1440m (96%)       1 (66%)

This VM has two CPU cores. The system-reserved setting reserves 500 millicores, meaning that half of one core is subtracted from the total capacity of the node to arrive at the Node Allocatable amount. You can see that Allocatable CPU is 1500 millicores. This means you can run one of the CPU Manager pods since each will take one whole core. A whole core is equivalent to 1000 millicores. If you try to schedule a second pod, the system will accept the pod, but it will never be scheduled:

NAME                    READY   STATUS    RESTARTS   AGE
cpumanager-6cqz7        1/1     Running   0          33m
cpumanager-7qc2t        0/1     Pending   0          11s

8.2. Topology Manager policies

Topology Manager aligns Pod resources of all Quality of Service (QoS) classes by collecting topology hints from Hint Providers, such as CPU Manager and Device Manager, and using the collected hints to align the Pod resources.

Topology Manager supports four allocation policies, which you assign in the KubeletConfig custom resource (CR) named cpumanager-enabled:

none policy: This is the default policy and does not perform any topology alignment.
best-effort policy: For each container in a pod with the best-effort topology management policy, kubelet calls each Hint Provider to discover their resource availability. Using this information, the Topology Manager stores the preferred NUMA Node affinity for that container. If the affinity is not preferred, Topology Manager stores this and admits the pod to the node.
restricted policy: For each container in a pod with the restricted topology management policy, kubelet calls each Hint Provider to discover their resource availability. Using this information, the Topology Manager stores the preferred NUMA Node affinity for that container. If the affinity is not preferred, Topology Manager rejects this pod from the node, resulting in a pod in a Terminated state with a pod admission failure.
single-numa-node policy: For each container in a pod with the single-numa-node topology management policy, kubelet calls each Hint Provider to discover their resource availability. Using this information, the Topology Manager determines if a single NUMA Node affinity is possible. If it is, the pod is admitted to the node. If a single NUMA Node affinity is not possible, the Topology Manager rejects the pod from the node. This results in a pod in a Terminated state with a pod admission failure.

8.3. Setting up Topology Manager

To use Topology Manager, you must configure an allocation policy in the KubeletConfig custom resource (CR) named cpumanager-enabled. This file might exist if you have set up CPU Manager. If the file does not exist, you can create the file.

Prerequisites

Configure the CPU Manager policy to be static.

Procedure

To activate Topology Manager:

Configure the Topology Manager allocation policy in the custom resource.

$ oc edit KubeletConfig cpumanager-enabled

apiVersion: machineconfiguration.openshift.io/v1
kind: KubeletConfig
metadata:
  name: cpumanager-enabled
spec:
  machineConfigPoolSelector:
    matchLabels:
      custom-kubelet: cpumanager-enabled
  kubeletConfig:
     cpuManagerPolicy: static 1
     cpuManagerReconcilePeriod: 5s
     topologyManagerPolicy: single-numa-node 2

1: This parameter must be static with a lowercase s.
2: Specify your selected Topology Manager allocation policy. Here, the policy is single-numa-node. Acceptable values are: default, best-effort, restricted, single-numa-node.

8.4. Pod interactions with Topology Manager policies

The example Pod specs below help illustrate pod interactions with Topology Manager.

The following pod runs in the BestEffort QoS class because no resource requests or limits are specified.

spec:
  containers:
  - name: nginx
    image: nginx

The next pod runs in the Burstable QoS class because requests are less than limits.

spec:
  containers:
  - name: nginx
    image: nginx
    resources:
      limits:
        memory: "200Mi"
      requests:
        memory: "100Mi"

If the selected policy is anything other than none, Topology Manager would not consider either of these Pod specifications.

The last example pod below runs in the Guaranteed QoS class because requests are equal to limits.

spec:
  containers:
  - name: nginx
    image: nginx
    resources:
      limits:
        memory: "200Mi"
        cpu: "2"
        example.com/device: "1"
      requests:
        memory: "200Mi"
        cpu: "2"
        example.com/device: "1"

Topology Manager would consider this pod. The Topology Manager would consult the hint providers, which are CPU Manager and Device Manager, to get topology hints for the pod.

Topology Manager will use this information to store the best topology for this container. In the case of this pod, CPU Manager and Device Manager will use this stored information at the resource allocation stage.

Chapter 9. Scheduling NUMA-aware workloads

Learn about NUMA-aware scheduling and how you can use it to deploy high performance workloads in an OpenShift Container Platform cluster.

The NUMA Resources Operator allows you to schedule high-performance workloads in the same NUMA zone. It deploys a node resources exporting agent that reports on available cluster node NUMA resources, and a secondary scheduler that manages the workloads.

9.1. About NUMA-aware scheduling

Introduction to NUMA

Non-Uniform Memory Access (NUMA) is a compute platform architecture that allows different CPUs to access different regions of memory at different speeds. NUMA resource topology refers to the locations of CPUs, memory, and PCI devices relative to each other in the compute node. Colocated resources are said to be in the same NUMA zone. For high-performance applications, the cluster needs to process pod workloads in a single NUMA zone.

Performance considerations

NUMA architecture allows a CPU with multiple memory controllers to use any available memory across CPU complexes, regardless of where the memory is located. This allows for increased flexibility at the expense of performance. A CPU processing a workload using memory that is outside its NUMA zone is slower than a workload processed in a single NUMA zone. Also, for I/O-constrained workloads, the network interface on a distant NUMA zone slows down how quickly information can reach the application. High-performance workloads, such as telecommunications workloads, cannot operate to specification under these conditions.

NUMA-aware scheduling

NUMA-aware scheduling aligns the requested cluster compute resources (CPUs, memory, devices) in the same NUMA zone to process latency-sensitive or high-performance workloads efficiently. NUMA-aware scheduling also improves pod density per compute node for greater resource efficiency.

Integration with Node Tuning Operator

By integrating the Node Tuning Operator’s performance profile with NUMA-aware scheduling, you can further configure CPU affinity to optimize performance for latency-sensitive workloads.

Default scheduling logic

The default OpenShift Container Platform pod scheduler scheduling logic considers the available resources of the entire compute node, not individual NUMA zones. If the most restrictive resource alignment is requested in the kubelet topology manager, error conditions can occur when admitting the pod to a node. Conversely, if the most restrictive resource alignment is not requested, the pod can be admitted to the node without proper resource alignment, leading to worse or unpredictable performance. For example, runaway pod creation with Topology Affinity Error statuses can occur when the pod scheduler makes suboptimal scheduling decisions for guaranteed pod workloads without knowing if the pod’s requested resources are available. Scheduling mismatch decisions can cause indefinite pod startup delays. Also, depending on the cluster state and resource allocation, poor pod scheduling decisions can cause extra load on the cluster because of failed startup attempts.

NUMA-aware pod scheduling diagram

The NUMA Resources Operator deploys a custom NUMA resources secondary scheduler and other resources to mitigate against the shortcomings of the default OpenShift Container Platform pod scheduler. The following diagram provides a high-level overview of NUMA-aware pod scheduling.

Figure 9.1. NUMA-aware scheduling overview

Diagram of NUMA-aware scheduling that shows how the various components interact with each other in the cluster

NodeResourceTopology API: The NodeResourceTopology API describes the available NUMA zone resources in each compute node.
NUMA-aware scheduler: The NUMA-aware secondary scheduler receives information about the available NUMA zones from the NodeResourceTopology API and schedules high-performance workloads on a node where it can be optimally processed.
Node topology exporter: The node topology exporter exposes the available NUMA zone resources for each compute node to the NodeResourceTopology API. The node topology exporter daemon tracks the resource allocation from the kubelet by using the PodResources API.
PodResources API: The PodResources API is local to each node and exposes the resource topology and available resources to the kubelet.
Note
The List endpoint of the PodResources API exposes exclusive CPUs allocated to a particular container. The API does not expose CPUs that belong to a shared pool.
The GetAllocatableResources endpoint exposes allocatable resources available on a node.

Additional resources

For more information about running secondary pod schedulers in your cluster and how to deploy pods with a secondary pod scheduler, see Scheduling pods using a secondary scheduler.

9.2. Installing the NUMA Resources Operator

NUMA Resources Operator deploys resources that allow you to schedule NUMA-aware workloads and deployments. You can install the NUMA Resources Operator using the OpenShift Container Platform CLI or the web console.

9.2.1. Installing the NUMA Resources Operator using the CLI

As a cluster administrator, you can install the Operator using the CLI.

Prerequisites

Install the OpenShift CLI (oc).
Log in as a user with cluster-admin privileges.

Procedure

Create a namespace for the NUMA Resources Operator:
1. Save the following YAML in the nro-namespace.yaml file:
```
apiVersion: v1
kind: Namespace
metadata:
  name: openshift-numaresources
```
2. Create the Namespace CR by running the following command:
```
$ oc create -f nro-namespace.yaml
```

Create the Operator group for the NUMA Resources Operator:

Save the following YAML in the nro-operatorgroup.yaml file:

apiVersion: operators.coreos.com/v1
kind: OperatorGroup
metadata:
  name: numaresources-operator
  namespace: openshift-numaresources
spec:
  targetNamespaces:
  - openshift-numaresources

Create the OperatorGroup CR by running the following command:
```
$ oc create -f nro-operatorgroup.yaml
```

Create the subscription for the NUMA Resources Operator:

Save the following YAML in the nro-sub.yaml file:

apiVersion: operators.coreos.com/v1alpha1
kind: Subscription
metadata:
  name: numaresources-operator
  namespace: openshift-numaresources
spec:
  channel: "4.14"
  name: numaresources-operator
  source: redhat-operators
  sourceNamespace: openshift-marketplace

Create the Subscription CR by running the following command:
```
$ oc create -f nro-sub.yaml
```

Verification

Verify that the installation succeeded by inspecting the CSV resource in the openshift-numaresources namespace. Run the following command:

$ oc get csv -n openshift-numaresources

Example output

NAME                             DISPLAY                  VERSION   REPLACES   PHASE
numaresources-operator.v4.14.2   numaresources-operator   4.14.2               Succeeded

9.2.2. Installing the NUMA Resources Operator using the web console

As a cluster administrator, you can install the NUMA Resources Operator using the web console.

Procedure

Create a namespace for the NUMA Resources Operator:
1. In the OpenShift Container Platform web console, click Administration → Namespaces.
2. Click Create Namespace, enter openshift-numaresources in the Name field, and then click Create.
Install the NUMA Resources Operator:
1. In the OpenShift Container Platform web console, click Operators → OperatorHub.
2. Choose numaresources-operator from the list of available Operators, and then click Install.
3. In the Installed Namespaces field, select the openshift-numaresources namespace, and then click Install.
Optional: Verify that the NUMA Resources Operator installed successfully:
1. Switch to the Operators → Installed Operators page.
2. Ensure that NUMA Resources Operator is listed in the openshift-numaresources namespace with a Status of InstallSucceeded.
  Note
  During installation an Operator might display a Failed status. If the installation later succeeds with an InstallSucceeded message, you can ignore the Failed message.
  If the Operator does not appear as installed, to troubleshoot further:
  - Go to the Operators → Installed Operators page and inspect the Operator Subscriptions and Install Plans tabs for any failure or errors under Status.
  - Go to the Workloads → Pods page and check the logs for pods in the default project.

9.3. Scheduling NUMA-aware workloads

Clusters running latency-sensitive workloads typically feature performance profiles that help to minimize workload latency and optimize performance. The NUMA-aware scheduler deploys workloads based on available node NUMA resources and with respect to any performance profile settings applied to the node. The combination of NUMA-aware deployments, and the performance profile of the workload, ensures that workloads are scheduled in a way that maximizes performance.

For the NUMA Resources Operator to be fully operational, you must deploy the NUMAResourcesOperator custom resource and the NUMA-aware secondary pod scheduler.

9.3.1. Creating the NUMAResourcesOperator custom resource

When you have installed the NUMA Resources Operator, then create the NUMAResourcesOperator custom resource (CR) that instructs the NUMA Resources Operator to install all the cluster infrastructure needed to support the NUMA-aware scheduler, including daemon sets and APIs.

Prerequisites

Install the OpenShift CLI (oc).
Log in as a user with cluster-admin privileges.
Install the NUMA Resources Operator.

Procedure

Create the NUMAResourcesOperator custom resource:
1. Save the following minimal required YAML file example as nrop.yaml:
```
apiVersion: nodetopology.openshift.io/v1
kind: NUMAResourcesOperator
metadata:
  name: numaresourcesoperator
spec:
  nodeGroups:
  - machineConfigPoolSelector:
      matchLabels:
        pools.operator.machineconfiguration.openshift.io/worker: "" 1
```
  1
  This should match the MachineConfigPool that you want to configure the NUMA Resources Operator on. For example, you might have created a MachineConfigPool named worker-cnf that designates a set of nodes expected to run telecommunications workloads.
2. Create the NUMAResourcesOperator CR by running the following command:
```
$ oc create -f nrop.yaml
```
  Note
  Creating the NUMAResourcesOperator triggers a reboot on the corresponding machine config pool and therefore the affected node.

Verification

Verify that the NUMA Resources Operator deployed successfully by running the following command:

$ oc get numaresourcesoperators.nodetopology.openshift.io

Example output

NAME                    AGE
numaresourcesoperator   27s

After a few minutes, run the following command to verify that the required resources deployed successfully:

$ oc get all -n openshift-numaresources

Example output

NAME                                                    READY   STATUS    RESTARTS   AGE
pod/numaresources-controller-manager-7d9d84c58d-qk2mr   1/1     Running   0          12m
pod/numaresourcesoperator-worker-7d96r                  2/2     Running   0          97s
pod/numaresourcesoperator-worker-crsht                  2/2     Running   0          97s
pod/numaresourcesoperator-worker-jp9mw                  2/2     Running   0          97s

9.3.2. Deploying the NUMA-aware secondary pod scheduler

After installing the NUMA Resources Operator, deploy the NUMA-aware secondary pod scheduler to optimize pod placement for improved performance and reduced latency in NUMA-based systems.

Procedure

Create the NUMAResourcesScheduler custom resource that deploys the NUMA-aware custom pod scheduler:
1. Save the following minimal required YAML in the nro-scheduler.yaml file:
```
apiVersion: nodetopology.openshift.io/v1
kind: NUMAResourcesScheduler
metadata:
  name: numaresourcesscheduler
spec:
  imageSpec: "registry.redhat.io/openshift4/noderesourcetopology-scheduler-rhel9:v4.14" 1
```
  1
  In a disconnected environment, make sure to configure the resolution of this image by completing one of the following actions:
  Creating an ImageTagMirrorSet custom resource (CR). For more information, see "Configuring image registry repository mirroring" in the "Additional resources" section.
  Setting the URL to the disconnected registry.
2. Create the NUMAResourcesScheduler CR by running the following command:
```
$ oc create -f nro-scheduler.yaml
```

After a few seconds, run the following command to confirm the successful deployment of the required resources:

$ oc get all -n openshift-numaresources

Example output

NAME                                                    READY   STATUS    RESTARTS   AGE
pod/numaresources-controller-manager-7d9d84c58d-qk2mr   1/1     Running   0          12m
pod/numaresourcesoperator-worker-7d96r                  2/2     Running   0          97s
pod/numaresourcesoperator-worker-crsht                  2/2     Running   0          97s
pod/numaresourcesoperator-worker-jp9mw                  2/2     Running   0          97s
pod/secondary-scheduler-847cb74f84-9whlm                1/1     Running   0          10m

NAME                                          DESIRED   CURRENT   READY   UP-TO-DATE   AVAILABLE   NODE SELECTOR                     AGE
daemonset.apps/numaresourcesoperator-worker   3         3         3       3            3           node-role.kubernetes.io/worker=   98s

NAME                                               READY   UP-TO-DATE   AVAILABLE   AGE
deployment.apps/numaresources-controller-manager   1/1     1            1           12m
deployment.apps/secondary-scheduler                1/1     1            1           10m

NAME                                                          DESIRED   CURRENT   READY   AGE
replicaset.apps/numaresources-controller-manager-7d9d84c58d   1         1         1       12m
replicaset.apps/secondary-scheduler-847cb74f84                1         1         1       10m

Additional resources

Configuring image registry repository mirroring

9.3.3. Configuring a single NUMA node policy

The NUMA Resources Operator requires a single NUMA node policy to be configured on the cluster. This can be achieved in two ways: by creating and applying a performance profile, or by configuring a KubeletConfig.

Note

The preferred way to configure a single NUMA node policy is to apply a performance profile. You can use the Performance Profile Creator (PPC) tool to create the performance profile. If a performance profile is created on the cluster, it automatically creates other tuning components like KubeletConfig and the tuned profile.

For more information about creating a performance profile, see "About the Performance Profile Creator" in the "Additional resources" section.

Additional resources

About the Performance Profile Creator

9.3.4. Sample performance profile

This example YAML shows a performance profile created by using the performance profile creator (PPC) tool:

apiVersion: performance.openshift.io/v2
kind: PerformanceProfile
metadata:
  name: performance
spec:
  cpu:
    isolated: "3"
    reserved: 0-2
  machineConfigPoolSelector:
    pools.operator.machineconfiguration.openshift.io/worker: "" 1
  nodeSelector:
    node-role.kubernetes.io/worker: ""
  numa:
    topologyPolicy: single-numa-node 2
  realTimeKernel:
    enabled: true
  workloadHints:
    highPowerConsumption: true
    perPodPowerManagement: false
    realTime: true

1: This should match the MachineConfigPool that you want to configure the NUMA Resources Operator on. For example, you might have created a MachineConfigPool named worker-cnf that designates a set of nodes that run telecommunications workloads.
2: The topologyPolicy must be set to single-numa-node. Ensure that this is the case by setting the topology-manager-policy argument to single-numa-node when running the PPC tool.

9.3.5. Creating a KubeletConfig CRD

The recommended way to configure a single NUMA node policy is to apply a performance profile. Another way is by creating and applying a KubeletConfig custom resource (CR), as shown in the following procedure.

Procedure

Create the KubeletConfig custom resource (CR) that configures the pod admittance policy for the machine profile:
1. Save the following YAML in the nro-kubeletconfig.yaml file:
```
apiVersion: machineconfiguration.openshift.io/v1
kind: KubeletConfig
metadata:
  name: worker-tuning
spec:
  machineConfigPoolSelector:
    matchLabels:
      pools.operator.machineconfiguration.openshift.io/worker: "" 1
  kubeletConfig:
    cpuManagerPolicy: "static" 2
    cpuManagerReconcilePeriod: "5s"
    reservedSystemCPUs: "0,1" 3
    memoryManagerPolicy: "Static" 4
    evictionHard:
      memory.available: "100Mi"
    kubeReserved:
      memory: "512Mi"
    reservedMemory:
      - numaNode: 0
        limits:
          memory: "1124Mi"
    systemReserved:
      memory: "512Mi"
    topologyManagerPolicy: "single-numa-node" 5
```
  1
  Adjust this label to match the machineConfigPoolSelector in the NUMAResourcesOperator CR.
  2
  For cpuManagerPolicy, static must use a lowercase s.
  3
  Adjust this based on the CPU on your nodes.
  4
  For memoryManagerPolicy, Static must use an uppercase S.
  5
  topologyManagerPolicy must be set to single-numa-node.
2. Create the KubeletConfig CR by running the following command:
```
$ oc create -f nro-kubeletconfig.yaml
```
  Note
  Applying performance profile or KubeletConfig automatically triggers rebooting of the nodes. If no reboot is triggered, you can troubleshoot the issue by looking at the labels in KubeletConfig that address the node group.

9.3.6. Scheduling workloads with the NUMA-aware scheduler

Now that topo-aware-scheduler is installed, the NUMAResourcesOperator and NUMAResourcesScheduler CRs are applied and your cluster has a matching performance profile or kubeletconfig, you can schedule workloads with the NUMA-aware scheduler using deployment CRs that specify the minimum required resources to process the workload.

The following example deployment uses NUMA-aware scheduling for a sample workload.

Prerequisites

Install the OpenShift CLI (oc).
Log in as a user with cluster-admin privileges.

Procedure

Get the name of the NUMA-aware scheduler that is deployed in the cluster by running the following command:

$ oc get numaresourcesschedulers.nodetopology.openshift.io numaresourcesscheduler -o json | jq '.status.schedulerName'

Example output

"topo-aware-scheduler"

Create a Deployment CR that uses scheduler named topo-aware-scheduler, for example:

Save the following YAML in the nro-deployment.yaml file:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: numa-deployment-1
  namespace: openshift-numaresources
spec:
  replicas: 1
  selector:
    matchLabels:
      app: test
  template:
    metadata:
      labels:
        app: test
    spec:
      schedulerName: topo-aware-scheduler 1
      containers:
      - name: ctnr
        image: quay.io/openshifttest/hello-openshift:openshift
        imagePullPolicy: IfNotPresent
        resources:
          limits:
            memory: "100Mi"
            cpu: "10"
          requests:
            memory: "100Mi"
            cpu: "10"
      - name: ctnr2
        image: registry.access.redhat.com/rhel:latest
        imagePullPolicy: IfNotPresent
        command: ["/bin/sh", "-c"]
        args: [ "while true; do sleep 1h; done;" ]
        resources:
          limits:
            memory: "100Mi"
            cpu: "8"
          requests:
            memory: "100Mi"
            cpu: "8"

1: schedulerName must match the name of the NUMA-aware scheduler that is deployed in your cluster, for example topo-aware-scheduler.

Create the Deployment CR by running the following command:
```
$ oc create -f nro-deployment.yaml
```

Verification

Verify that the deployment was successful:

$ oc get pods -n openshift-numaresources

Example output

NAME                                                READY   STATUS    RESTARTS   AGE
numa-deployment-1-6c4f5bdb84-wgn6g                  2/2     Running   0          5m2s
numaresources-controller-manager-7d9d84c58d-4v65j   1/1     Running   0          18m
numaresourcesoperator-worker-7d96r                  2/2     Running   4          43m
numaresourcesoperator-worker-crsht                  2/2     Running   2          43m
numaresourcesoperator-worker-jp9mw                  2/2     Running   2          43m
secondary-scheduler-847cb74f84-fpncj                1/1     Running   0          18m

Verify that the topo-aware-scheduler is scheduling the deployed pod by running the following command:
```
$ oc describe pod numa-deployment-1-6c4f5bdb84-wgn6g -n openshift-numaresources
```
Example output
```
Events:
  Type    Reason          Age    From                  Message
  ----    ------          ----   ----                  -------
  Normal  Scheduled       4m45s  topo-aware-scheduler  Successfully assigned openshift-numaresources/numa-deployment-1-6c4f5bdb84-wgn6g to worker-1
```
Note
Deployments that request more resources than is available for scheduling will fail with a MinimumReplicasUnavailable error. The deployment succeeds when the required resources become available. Pods remain in the Pending state until the required resources are available.

Verify that the expected allocated resources are listed for the node.

Identify the node that is running the deployment pod by running the following command:

$ oc get pods -n openshift-numaresources -o wide

Example output

NAME                                 READY   STATUS    RESTARTS   AGE   IP            NODE     NOMINATED NODE   READINESS GATES
numa-deployment-1-6c4f5bdb84-wgn6g   0/2     Running   0          82m   10.128.2.50   worker-1   <none>  <none>

Run the following command with the name of that node that is running the deployment pod.

$ oc describe noderesourcetopologies.topology.node.k8s.io worker-1

Example output

...

Zones:
  Costs:
    Name:   node-0
    Value:  10
    Name:   node-1
    Value:  21
  Name:     node-0
  Resources:
    Allocatable:  39
    Available:    21 1
    Capacity:     40
    Name:         cpu
    Allocatable:  6442450944
    Available:    6442450944
    Capacity:     6442450944
    Name:         hugepages-1Gi
    Allocatable:  134217728
    Available:    134217728
    Capacity:     134217728
    Name:         hugepages-2Mi
    Allocatable:  262415904768
    Available:    262206189568
    Capacity:     270146007040
    Name:         memory
  Type:           Node

1: The Available capacity is reduced because of the resources that have been allocated to the guaranteed pod.

Resources consumed by guaranteed pods are subtracted from the available node resources listed under noderesourcetopologies.topology.node.k8s.io.

Resource allocations for pods with a Best-effort or Burstable quality of service (qosClass) are not reflected in the NUMA node resources under noderesourcetopologies.topology.node.k8s.io. If a pod’s consumed resources are not reflected in the node resource calculation, verify that the pod has qosClass of Guaranteed and the CPU request is an integer value, not a decimal value. You can verify the that the pod has a qosClass of Guaranteed by running the following command:
```
$ oc get pod numa-deployment-1-6c4f5bdb84-wgn6g -n openshift-numaresources -o jsonpath="{ .status.qosClass }"
```
Example output
```
Guaranteed
```

9.4. Optional: Configuring polling operations for NUMA resources updates

The daemons controlled by the NUMA Resources Operator in their nodeGroup poll resources to retrieve updates about available NUMA resources. You can fine-tune polling operations for these daemons by configuring the spec.nodeGroups specification in the NUMAResourcesOperator custom resource (CR). This provides advanced control of polling operations. Configure these specifications to improve scheduling behaviour and troubleshoot suboptimal scheduling decisions.

The configuration options are the following:

infoRefreshMode: Determines the trigger condition for polling the kubelet. The NUMA Resources Operator reports the resulting information to the API server.
infoRefreshPeriod: Determines the duration between polling updates.
podsFingerprinting: Determines if point-in-time information for the current set of pods running on a node is exposed in polling updates.
Note
podsFingerprinting is enabled by default. podsFingerprinting is a requirement for the cacheResyncPeriod specification in the NUMAResourcesScheduler CR. The cacheResyncPeriod specification helps to report more exact resource availability by monitoring pending resources on nodes.

Prerequisites

Install the OpenShift CLI (oc).
Log in as a user with cluster-admin privileges.
Install the NUMA Resources Operator.

Procedure

Configure the spec.nodeGroups specification in your NUMAResourcesOperator CR:
```
apiVersion: nodetopology.openshift.io/v1
kind: NUMAResourcesOperator
metadata:
  name: numaresourcesoperator
spec:
  nodeGroups:
  - config:
      infoRefreshMode: Periodic 1
      infoRefreshPeriod: 10s 2
      podsFingerprinting: Enabled 3
    name: worker
```
1
Valid values are Periodic, Events, PeriodicAndEvents. Use Periodic to poll the kubelet at intervals that you define in infoRefreshPeriod. Use Events to poll the kubelet at every pod lifecycle event. Use PeriodicAndEvents to enable both methods.
2
Define the polling interval for Periodic or PeriodicAndEvents refresh modes. The field is ignored if the refresh mode is Events.
3
Valid values are Enabled, Disabled, and EnabledExclusiveResources. Setting to Enabled is a requirement for the cacheResyncPeriod specification in the NUMAResourcesScheduler.

Verification

After you deploy the NUMA Resources Operator, verify that the node group configurations were applied by running the following command:

$ oc get numaresop numaresourcesoperator -o json | jq '.status'

Example output

      ...

        "config": {
        "infoRefreshMode": "Periodic",
        "infoRefreshPeriod": "10s",
        "podsFingerprinting": "Enabled"
      },
      "name": "worker"

      ...

9.5. Troubleshooting NUMA-aware scheduling

To troubleshoot common problems with NUMA-aware pod scheduling, perform the following steps.

Prerequisites

Install the OpenShift Container Platform CLI (oc).
Log in as a user with cluster-admin privileges.
Install the NUMA Resources Operator and deploy the NUMA-aware secondary scheduler.

Procedure

Verify that the noderesourcetopologies CRD is deployed in the cluster by running the following command:

$ oc get crd | grep noderesourcetopologies

Example output

NAME                                                              CREATED AT
noderesourcetopologies.topology.node.k8s.io                       2022-01-18T08:28:06Z

Check that the NUMA-aware scheduler name matches the name specified in your NUMA-aware workloads by running the following command:
```
$ oc get numaresourcesschedulers.nodetopology.openshift.io numaresourcesscheduler -o json | jq '.status.schedulerName'
```
Example output
```
topo-aware-scheduler
```
Verify that NUMA-aware schedulable nodes have the noderesourcetopologies CR applied to them. Run the following command:
```
$ oc get noderesourcetopologies.topology.node.k8s.io
```
Example output
```
NAME                    AGE
compute-0.example.com   17h
compute-1.example.com   17h
```
Note
The number of nodes should equal the number of worker nodes that are configured by the machine config pool (mcp) worker definition.

Verify the NUMA zone granularity for all schedulable nodes by running the following command:

$ oc get noderesourcetopologies.topology.node.k8s.io -o yaml

Example output

apiVersion: v1
items:
- apiVersion: topology.node.k8s.io/v1
  kind: NodeResourceTopology
  metadata:
    annotations:
      k8stopoawareschedwg/rte-update: periodic
    creationTimestamp: "2022-06-16T08:55:38Z"
    generation: 63760
    name: worker-0
    resourceVersion: "8450223"
    uid: 8b77be46-08c0-4074-927b-d49361471590
  topologyPolicies:
  - SingleNUMANodeContainerLevel
  zones:
  - costs:
    - name: node-0
      value: 10
    - name: node-1
      value: 21
    name: node-0
    resources:
    - allocatable: "38"
      available: "38"
      capacity: "40"
      name: cpu
    - allocatable: "134217728"
      available: "134217728"
      capacity: "134217728"
      name: hugepages-2Mi
    - allocatable: "262352048128"
      available: "262352048128"
      capacity: "270107316224"
      name: memory
    - allocatable: "6442450944"
      available: "6442450944"
      capacity: "6442450944"
      name: hugepages-1Gi
    type: Node
  - costs:
    - name: node-0
      value: 21
    - name: node-1
      value: 10
    name: node-1
    resources:
    - allocatable: "268435456"
      available: "268435456"
      capacity: "268435456"
      name: hugepages-2Mi
    - allocatable: "269231067136"
      available: "269231067136"
      capacity: "270573244416"
      name: memory
    - allocatable: "40"
      available: "40"
      capacity: "40"
      name: cpu
    - allocatable: "1073741824"
      available: "1073741824"
      capacity: "1073741824"
      name: hugepages-1Gi
    type: Node
- apiVersion: topology.node.k8s.io/v1
  kind: NodeResourceTopology
  metadata:
    annotations:
      k8stopoawareschedwg/rte-update: periodic
    creationTimestamp: "2022-06-16T08:55:37Z"
    generation: 62061
    name: worker-1
    resourceVersion: "8450129"
    uid: e8659390-6f8d-4e67-9a51-1ea34bba1cc3
  topologyPolicies:
  - SingleNUMANodeContainerLevel
  zones: 1
  - costs:
    - name: node-0
      value: 10
    - name: node-1
      value: 21
    name: node-0
    resources: 2
    - allocatable: "38"
      available: "38"
      capacity: "40"
      name: cpu
    - allocatable: "6442450944"
      available: "6442450944"
      capacity: "6442450944"
      name: hugepages-1Gi
    - allocatable: "134217728"
      available: "134217728"
      capacity: "134217728"
      name: hugepages-2Mi
    - allocatable: "262391033856"
      available: "262391033856"
      capacity: "270146301952"
      name: memory
    type: Node
  - costs:
    - name: node-0
      value: 21
    - name: node-1
      value: 10
    name: node-1
    resources:
    - allocatable: "40"
      available: "40"
      capacity: "40"
      name: cpu
    - allocatable: "1073741824"
      available: "1073741824"
      capacity: "1073741824"
      name: hugepages-1Gi
    - allocatable: "268435456"
      available: "268435456"
      capacity: "268435456"
      name: hugepages-2Mi
    - allocatable: "269192085504"
      available: "269192085504"
      capacity: "270534262784"
      name: memory
    type: Node
kind: List
metadata:
  resourceVersion: ""
  selfLink: ""

1: Each stanza under zones describes the resources for a single NUMA zone.
2: resources describes the current state of the NUMA zone resources. Check that resources listed under items.zones.resources.available correspond to the exclusive NUMA zone resources allocated to each guaranteed pod.

9.5.1. Reporting more exact resource availability

Enable the cacheResyncPeriod specification to help the NUMA Resources Operator report more exact resource availability by monitoring pending resources on nodes and synchronizing this information in the scheduler cache at a defined interval. This also helps to minimize Topology Affinity Error errors because of sub-optimal scheduling decisions. The lower the interval, the greater the network load. The cacheResyncPeriod specification is disabled by default.

Prerequisites

Install the OpenShift CLI (oc).
Log in as a user with cluster-admin privileges.

Procedure

Delete the currently running NUMAResourcesScheduler resource:
1. Get the active NUMAResourcesScheduler by running the following command:
```
$ oc get NUMAResourcesScheduler
```
  Example output
```
NAME                     AGE
numaresourcesscheduler   92m
```
2. Delete the secondary scheduler resource by running the following command:
```
$ oc delete NUMAResourcesScheduler numaresourcesscheduler
```
  Example output
```
numaresourcesscheduler.nodetopology.openshift.io "numaresourcesscheduler" deleted
```

Save the following YAML in the file nro-scheduler-cacheresync.yaml. This example changes the log level to Debug:

apiVersion: nodetopology.openshift.io/v1
kind: NUMAResourcesScheduler
metadata:
  name: numaresourcesscheduler
spec:
  imageSpec: "registry.redhat.io/openshift4/noderesourcetopology-scheduler-container-rhel8:v4.14"
  cacheResyncPeriod: "5s" 1

1: Enter an interval value in seconds for synchronization of the scheduler cache. A value of 5s is typical for most implementations.

Create the updated NUMAResourcesScheduler resource by running the following command:

$ oc create -f nro-scheduler-cacheresync.yaml

Example output

numaresourcesscheduler.nodetopology.openshift.io/numaresourcesscheduler created

Verification steps

Check that the NUMA-aware scheduler was successfully deployed:

Run the following command to check that the CRD is created successfully:

$ oc get crd | grep numaresourcesschedulers

Example output

NAME                                                              CREATED AT
numaresourcesschedulers.nodetopology.openshift.io                 2022-02-25T11:57:03Z

Check that the new custom scheduler is available by running the following command:

$ oc get numaresourcesschedulers.nodetopology.openshift.io

Example output

NAME                     AGE
numaresourcesscheduler   3h26m

Check that the logs for the scheduler show the increased log level:

Get the list of pods running in the openshift-numaresources namespace by running the following command:

$ oc get pods -n openshift-numaresources

Example output

NAME                                               READY   STATUS    RESTARTS   AGE
numaresources-controller-manager-d87d79587-76mrm   1/1     Running   0          46h
numaresourcesoperator-worker-5wm2k                 2/2     Running   0          45h
numaresourcesoperator-worker-pb75c                 2/2     Running   0          45h
secondary-scheduler-7976c4d466-qm4sc               1/1     Running   0          21m

Get the logs for the secondary scheduler pod by running the following command:

$ oc logs secondary-scheduler-7976c4d466-qm4sc -n openshift-numaresources

Example output

...
I0223 11:04:55.614788       1 reflector.go:535] k8s.io/client-go/informers/factory.go:134: Watch close - *v1.Namespace total 11 items received
I0223 11:04:56.609114       1 reflector.go:535] k8s.io/client-go/informers/factory.go:134: Watch close - *v1.ReplicationController total 10 items received
I0223 11:05:22.626818       1 reflector.go:535] k8s.io/client-go/informers/factory.go:134: Watch close - *v1.StorageClass total 7 items received
I0223 11:05:31.610356       1 reflector.go:535] k8s.io/client-go/informers/factory.go:134: Watch close - *v1.PodDisruptionBudget total 7 items received
I0223 11:05:31.713032       1 eventhandlers.go:186] "Add event for scheduled pod" pod="openshift-marketplace/certified-operators-thtvq"
I0223 11:05:53.461016       1 eventhandlers.go:244] "Delete event for scheduled pod" pod="openshift-marketplace/certified-operators-thtvq"

9.5.2. Checking the NUMA-aware scheduler logs

Troubleshoot problems with the NUMA-aware scheduler by reviewing the logs. If required, you can increase the scheduler log level by modifying the spec.logLevel field of the NUMAResourcesScheduler resource. Acceptable values are Normal, Debug, and Trace, with Trace being the most verbose option.

Note

To change the log level of the secondary scheduler, delete the running scheduler resource and re-deploy it with the changed log level. The scheduler is unavailable for scheduling new workloads during this downtime.

Prerequisites

Install the OpenShift CLI (oc).
Log in as a user with cluster-admin privileges.

Procedure

Delete the currently running NUMAResourcesScheduler resource:
1. Get the active NUMAResourcesScheduler by running the following command:
```
$ oc get NUMAResourcesScheduler
```
  Example output
```
NAME                     AGE
numaresourcesscheduler   90m
```
2. Delete the secondary scheduler resource by running the following command:
```
$ oc delete NUMAResourcesScheduler numaresourcesscheduler
```
  Example output
```
numaresourcesscheduler.nodetopology.openshift.io "numaresourcesscheduler" deleted
```

Save the following YAML in the file nro-scheduler-debug.yaml. This example changes the log level to Debug:

apiVersion: nodetopology.openshift.io/v1
kind: NUMAResourcesScheduler
metadata:
  name: numaresourcesscheduler
spec:
  imageSpec: "registry.redhat.io/openshift4/noderesourcetopology-scheduler-container-rhel8:v4.14"
  logLevel: Debug

Create the updated Debug logging NUMAResourcesScheduler resource by running the following command:

$ oc create -f nro-scheduler-debug.yaml

Example output

numaresourcesscheduler.nodetopology.openshift.io/numaresourcesscheduler created

Verification steps

Check that the NUMA-aware scheduler was successfully deployed:

Run the following command to check that the CRD is created successfully:

$ oc get crd | grep numaresourcesschedulers

Example output

NAME                                                              CREATED AT
numaresourcesschedulers.nodetopology.openshift.io                 2022-02-25T11:57:03Z

Check that the new custom scheduler is available by running the following command:

$ oc get numaresourcesschedulers.nodetopology.openshift.io

Example output

NAME                     AGE
numaresourcesscheduler   3h26m

Check that the logs for the scheduler shows the increased log level:

Get the list of pods running in the openshift-numaresources namespace by running the following command:

$ oc get pods -n openshift-numaresources

Example output

NAME                                               READY   STATUS    RESTARTS   AGE
numaresources-controller-manager-d87d79587-76mrm   1/1     Running   0          46h
numaresourcesoperator-worker-5wm2k                 2/2     Running   0          45h
numaresourcesoperator-worker-pb75c                 2/2     Running   0          45h
secondary-scheduler-7976c4d466-qm4sc               1/1     Running   0          21m

Get the logs for the secondary scheduler pod by running the following command:

$ oc logs secondary-scheduler-7976c4d466-qm4sc -n openshift-numaresources

Example output

...
I0223 11:04:55.614788       1 reflector.go:535] k8s.io/client-go/informers/factory.go:134: Watch close - *v1.Namespace total 11 items received
I0223 11:04:56.609114       1 reflector.go:535] k8s.io/client-go/informers/factory.go:134: Watch close - *v1.ReplicationController total 10 items received
I0223 11:05:22.626818       1 reflector.go:535] k8s.io/client-go/informers/factory.go:134: Watch close - *v1.StorageClass total 7 items received
I0223 11:05:31.610356       1 reflector.go:535] k8s.io/client-go/informers/factory.go:134: Watch close - *v1.PodDisruptionBudget total 7 items received
I0223 11:05:31.713032       1 eventhandlers.go:186] "Add event for scheduled pod" pod="openshift-marketplace/certified-operators-thtvq"
I0223 11:05:53.461016       1 eventhandlers.go:244] "Delete event for scheduled pod" pod="openshift-marketplace/certified-operators-thtvq"

9.5.3. Troubleshooting the resource topology exporter

Troubleshoot noderesourcetopologies objects where unexpected results are occurring by inspecting the corresponding resource-topology-exporter logs.

Note

It is recommended that NUMA resource topology exporter instances in the cluster are named for nodes they refer to. For example, a worker node with the name worker should have a corresponding noderesourcetopologies object called worker.

Prerequisites

Install the OpenShift CLI (oc).
Log in as a user with cluster-admin privileges.

Procedure

Get the daemonsets managed by the NUMA Resources Operator. Each daemonset has a corresponding nodeGroup in the NUMAResourcesOperator CR. Run the following command:

$ oc get numaresourcesoperators.nodetopology.openshift.io numaresourcesoperator -o jsonpath="{.status.daemonsets[0]}"

Example output

{"name":"numaresourcesoperator-worker","namespace":"openshift-numaresources"}

Get the label for the daemonset of interest using the value for name from the previous step:

$ oc get ds -n openshift-numaresources numaresourcesoperator-worker -o jsonpath="{.spec.selector.matchLabels}"

Example output

{"name":"resource-topology"}

Get the pods using the resource-topology label by running the following command:

$ oc get pods -n openshift-numaresources -l name=resource-topology -o wide

Example output

NAME                                 READY   STATUS    RESTARTS   AGE    IP            NODE
numaresourcesoperator-worker-5wm2k   2/2     Running   0          2d1h   10.135.0.64   compute-0.example.com
numaresourcesoperator-worker-pb75c   2/2     Running   0          2d1h   10.132.2.33   compute-1.example.com

Examine the logs of the resource-topology-exporter container running on the worker pod that corresponds to the node you are troubleshooting. Run the following command:

$ oc logs -n openshift-numaresources -c resource-topology-exporter numaresourcesoperator-worker-pb75c

Example output

I0221 13:38:18.334140       1 main.go:206] using sysinfo:
reservedCpus: 0,1
reservedMemory:
  "0": 1178599424
I0221 13:38:18.334370       1 main.go:67] === System information ===
I0221 13:38:18.334381       1 sysinfo.go:231] cpus: reserved "0-1"
I0221 13:38:18.334493       1 sysinfo.go:237] cpus: online "0-103"
I0221 13:38:18.546750       1 main.go:72]
cpus: allocatable "2-103"
hugepages-1Gi:
  numa cell 0 -> 6
  numa cell 1 -> 1
hugepages-2Mi:
  numa cell 0 -> 64
  numa cell 1 -> 128
memory:
  numa cell 0 -> 45758Mi
  numa cell 1 -> 48372Mi

9.5.4. Correcting a missing resource topology exporter config map

If you install the NUMA Resources Operator in a cluster with misconfigured cluster settings, in some circumstances, the Operator is shown as active but the logs of the resource topology exporter (RTE) daemon set pods show that the configuration for the RTE is missing, for example:

Info: couldn't find configuration in "/etc/resource-topology-exporter/config.yaml"

This log message indicates that the kubeletconfig with the required configuration was not properly applied in the cluster, resulting in a missing RTE configmap. For example, the following cluster is missing a numaresourcesoperator-worker configmap custom resource (CR):

$ oc get configmap

Example output

NAME                           DATA   AGE
0e2a6bd3.openshift-kni.io      0      6d21h
kube-root-ca.crt               1      6d21h
openshift-service-ca.crt       1      6d21h
topo-aware-scheduler-config    1      6d18h

In a correctly configured cluster, oc get configmap also returns a numaresourcesoperator-worker configmap CR.

Prerequisites

Install the OpenShift Container Platform CLI (oc).
Log in as a user with cluster-admin privileges.
Install the NUMA Resources Operator and deploy the NUMA-aware secondary scheduler.

Procedure

Compare the values for spec.machineConfigPoolSelector.matchLabels in kubeletconfig and metadata.labels in the MachineConfigPool (mcp) worker CR using the following commands:
1. Check the kubeletconfig labels by running the following command:
```
$ oc get kubeletconfig -o yaml
```
  Example output
```
machineConfigPoolSelector:
  matchLabels:
    cnf-worker-tuning: enabled
```
2. Check the mcp labels by running the following command:
```
$ oc get mcp worker -o yaml
```
  Example output
```
labels:
  machineconfiguration.openshift.io/mco-built-in: ""
  pools.operator.machineconfiguration.openshift.io/worker: ""
```
  The cnf-worker-tuning: enabled label is not present in the MachineConfigPool object.

Edit the MachineConfigPool CR to include the missing label, for example:

$ oc edit mcp worker -o yaml

Example output

labels:
  machineconfiguration.openshift.io/mco-built-in: ""
  pools.operator.machineconfiguration.openshift.io/worker: ""
  cnf-worker-tuning: enabled

Apply the label changes and wait for the cluster to apply the updated configuration. Run the following command:

Verification

Check that the missing numaresourcesoperator-worker configmap CR is applied:

$ oc get configmap

Example output

NAME                           DATA   AGE
0e2a6bd3.openshift-kni.io      0      6d21h
kube-root-ca.crt               1      6d21h
numaresourcesoperator-worker   1      5m
openshift-service-ca.crt       1      6d21h
topo-aware-scheduler-config    1      6d18h

9.5.5. Collecting NUMA Resources Operator data

You can use the oc adm must-gather CLI command to collect information about your cluster, including features and objects associated with the NUMA Resources Operator.

Prerequisites

You have access to the cluster as a user with the cluster-admin role.
You have installed the OpenShift CLI (oc).

Procedure

To collect NUMA Resources Operator data with must-gather, you must specify the NUMA Resources Operator must-gather image.
```
$ oc adm must-gather --image=registry.redhat.io/numaresources-must-gather/numaresources-must-gather-rhel9:v4.14
```

Chapter 10. Scalability and performance optimization

10.1. Optimizing storage

Optimizing storage helps to minimize storage use across all resources. By optimizing storage, administrators help ensure that existing storage resources are working in an efficient manner.

10.1.1. Available persistent storage options

Understand your persistent storage options so that you can optimize your OpenShift Container Platform environment.

Table 10.1. Available storage options
Storage type	Description	Examples
Block	Presented to the operating system (OS) as a block device Suitable for applications that need full control of storage and operate at a low level on files bypassing the file system Also referred to as a Storage Area Network (SAN) Non-shareable, which means that only one client at a time can mount an endpoint of this type	AWS EBS and VMware vSphere support dynamic persistent volume (PV) provisioning natively in the OpenShift Container Platform.
File	Presented to the OS as a file system export to be mounted Also referred to as Network Attached Storage (NAS) Concurrency, latency, file locking mechanisms, and other capabilities vary widely between protocols, implementations, vendors, and scales.	RHEL NFS, NetApp NFS ^[1], and Vendor NFS
Object	Accessible through a REST API endpoint Configurable for use in the OpenShift image registry Applications must build their drivers into the application and/or container.	AWS S3

NetApp NFS supports dynamic PV provisioning when using the Trident plugin.

10.1.2. Recommended configurable storage technology

The following table summarizes the recommended and configurable storage technologies for the given OpenShift Container Platform cluster application.

Table 10.2. Recommended and configurable storage technology
Storage type	Block	File	Object
¹ `ReadOnlyMany` ² `ReadWriteMany` ³ Prometheus is the underlying technology used for metrics. ⁴ This does not apply to physical disk, VM physical disk, VMDK, loopback over NFS, AWS EBS, and Azure Disk. ⁵ For metrics, using file storage with the `ReadWriteMany` (RWX) access mode is unreliable. If you use file storage, do not configure the RWX access mode on any persistent volume claims (PVCs) that are configured for use with metrics. ⁶ For logging, review the recommended storage solution in Configuring persistent storage for the log store section. Using NFS storage as a persistent volume or through NAS, such as Gluster, can corrupt the data. Hence, NFS is not supported for Elasticsearch storage and LokiStack log store in OpenShift Container Platform Logging. You must use one persistent volume type per log store. ⁷ Object storage is not consumed through OpenShift Container Platform’s PVs or PVCs. Apps must integrate with the object storage REST API.
ROX¹	Yes⁴	Yes⁴	Yes
RWX²	No	Yes	Yes
Registry	Configurable	Configurable	Recommended
Scaled registry	Not configurable	Configurable	Recommended
Metrics³	Recommended	Configurable⁵	Not configurable
Elasticsearch Logging	Recommended	Configurable⁶	Not supported⁶
Loki Logging	Not configurable	Not configurable	Recommended
Apps	Recommended	Recommended	Not configurable⁷

Note

A scaled registry is an OpenShift image registry where two or more pod replicas are running.

10.1.2.1. Specific application storage recommendations

Important

Testing shows issues with using the NFS server on Red Hat Enterprise Linux (RHEL) as a storage backend for core services. This includes the OpenShift Container Registry and Quay, Prometheus for monitoring storage, and Elasticsearch for logging storage. Therefore, using RHEL NFS to back PVs used by core services is not recommended.

Other NFS implementations in the marketplace might not have these issues. Contact the individual NFS implementation vendor for more information on any testing that was possibly completed against these OpenShift Container Platform core components.

10.1.2.1.1. Registry

In a non-scaled/high-availability (HA) OpenShift image registry cluster deployment:

The storage technology does not have to support RWX access mode.
The storage technology must ensure read-after-write consistency.
The preferred storage technology is object storage followed by block storage.
File storage is not recommended for OpenShift image registry cluster deployment with production workloads.

10.1.2.1.2. Scaled registry

In a scaled/HA OpenShift image registry cluster deployment:

The storage technology must support RWX access mode.
The storage technology must ensure read-after-write consistency.
The preferred storage technology is object storage.
Red Hat OpenShift Data Foundation (ODF), Amazon Simple Storage Service (Amazon S3), Google Cloud Storage (GCS), Microsoft Azure Blob Storage, and OpenStack Swift are supported.
Object storage should be S3 or Swift compliant.
For non-cloud platforms, such as vSphere and bare metal installations, the only configurable technology is file storage.
Block storage is not configurable.
The use of Network File System (NFS) storage with OpenShift Container Platform is supported. However, the use of NFS storage with a scaled registry can cause known issues. For more information, see the Red Hat Knowledgebase solution, Is NFS supported for OpenShift cluster internal components in Production?.

10.1.2.1.3. Metrics

In an OpenShift Container Platform hosted metrics cluster deployment:

The preferred storage technology is block storage.
Object storage is not configurable.

Important

It is not recommended to use file storage for a hosted metrics cluster deployment with production workloads.

10.1.2.1.4. Logging

In an OpenShift Container Platform hosted logging cluster deployment:

Loki Operator:
- The preferred storage technology is S3 compatible Object storage.
- Block storage is not configurable.
OpenShift Elasticsearch Operator:
- The preferred storage technology is block storage.
- Object storage is not supported.

Note

As of logging version 5.4.3 the OpenShift Elasticsearch Operator is deprecated and is planned to be removed in a future release. Red Hat will provide bug fixes and support for this feature during the current release lifecycle, but this feature will no longer receive enhancements and will be removed. As an alternative to using the OpenShift Elasticsearch Operator to manage the default log storage, you can use the Loki Operator.

10.1.2.1.5. Applications

Application use cases vary from application to application, as described in the following examples:

Storage technologies that support dynamic PV provisioning have low mount time latencies, and are not tied to nodes to support a healthy cluster.
Application developers are responsible for knowing and understanding the storage requirements for their application, and how it works with the provided storage to ensure that issues do not occur when an application scales or interacts with the storage layer.

10.1.2.2. Other specific application storage recommendations

Important

It is not recommended to use RAID configurations on Write intensive workloads, such as etcd. If you are running etcd with a RAID configuration, you might be at risk of encountering performance issues with your workloads.

Red Hat OpenStack Platform (RHOSP) Cinder: RHOSP Cinder tends to be adept in ROX access mode use cases.
Databases: Databases (RDBMSs, NoSQL DBs, etc.) tend to perform best with dedicated block storage.
The etcd database must have enough storage and adequate performance capacity to enable a large cluster. Information about monitoring and benchmarking tools to establish ample storage and a high-performance environment is described in Recommended etcd practices.

10.1.3. Data storage management

The following table summarizes the main directories that OpenShift Container Platform components write data to.

Table 10.3. Main directories for storing OpenShift Container Platform data
Directory	Notes	Sizing	Expected growth
*/var/log*	Log files for all components.	10 to 30 GB.	Log files can grow quickly; size can be managed by growing disks or by using log rotate.
*/var/lib/etcd*	Used for etcd storage when storing the database.	Less than 20 GB. Database can grow up to 8 GB.	Will grow slowly with the environment. Only storing metadata. Additional 20-25 GB for every additional 8 GB of memory.
*/var/lib/containers*	This is the mount point for the CRI-O runtime. Storage used for active container runtimes, including pods, and storage of local images. Not used for registry storage.	50 GB for a node with 16 GB memory. Note that this sizing should not be used to determine minimum cluster requirements. Additional 20-25 GB for every additional 8 GB of memory.	Growth is limited by capacity for running containers.
*/var/lib/kubelet*	Ephemeral volume storage for pods. This includes anything external that is mounted into a container at runtime. Includes environment variables, kube secrets, and data volumes not backed by persistent volumes.	Varies	Minimal if pods requiring storage are using persistent volumes. If using ephemeral storage, this can grow quickly.

10.1.4. Optimizing storage performance for Microsoft Azure

OpenShift Container Platform and Kubernetes are sensitive to disk performance, and faster storage is recommended, particularly for etcd on the control plane nodes.

For production Azure clusters and clusters with intensive workloads, the virtual machine operating system disk for control plane machines should be able to sustain a tested and recommended minimum throughput of 5000 IOPS / 200MBps. This throughput can be provided by having a minimum of 1 TiB Premium SSD (P30). In Azure and Azure Stack Hub, disk performance is directly dependent on SSD disk sizes. To achieve the throughput supported by a Standard_D8s_v3 virtual machine, or other similar machine types, and the target of 5000 IOPS, at least a P30 disk is required.

Host caching must be set to ReadOnly for low latency and high IOPS and throughput when reading data. Reading data from the cache, which is present either in the VM memory or in the local SSD disk, is much faster than reading from the disk, which is in the blob storage.

10.1.5. Additional resources

Configuring the Elasticsearch log store

10.2. Optimizing routing

The OpenShift Container Platform HAProxy router can be scaled or configured to optimize performance.

10.2.1. Baseline Ingress Controller (router) performance

The OpenShift Container Platform Ingress Controller, or router, is the ingress point for ingress traffic for applications and services that are configured using routes and ingresses.

When evaluating a single HAProxy router performance in terms of HTTP requests handled per second, the performance varies depending on many factors. In particular:

HTTP keep-alive/close mode
Route type
TLS session resumption client support
Number of concurrent connections per target route
Number of target routes
Back end server page size
Underlying infrastructure (network/SDN solution, CPU, and so on)

While performance in your specific environment will vary, Red Hat lab tests on a public cloud instance of size 4 vCPU/16GB RAM. A single HAProxy router handling 100 routes terminated by backends serving 1kB static pages is able to handle the following number of transactions per second.

In HTTP keep-alive mode scenarios:

Encryption	LoadBalancerService	HostNetwork
none	21515	29622
edge	16743	22913
passthrough	36786	53295
re-encrypt	21583	25198

In HTTP close (no keep-alive) scenarios:

Encryption	LoadBalancerService	HostNetwork
none	5719	8273
edge	2729	4069
passthrough	4121	5344
re-encrypt	2320	2941

The default Ingress Controller configuration was used with the spec.tuningOptions.threadCount field set to 4. Two different endpoint publishing strategies were tested: Load Balancer Service and Host Network. TLS session resumption was used for encrypted routes. With HTTP keep-alive, a single HAProxy router is capable of saturating a 1 Gbit NIC at page sizes as small as 8 kB.

When running on bare metal with modern processors, you can expect roughly twice the performance of the public cloud instance above. This overhead is introduced by the virtualization layer in place on public clouds and holds mostly true for private cloud-based virtualization as well. The following table is a guide to how many applications to use behind the router:

Number of applications	Application type
5-10	static file/web server or caching proxy
100-1000	applications generating dynamic content

In general, HAProxy can support routes for up to 1000 applications, depending on the technology in use. Ingress Controller performance might be limited by the capabilities and performance of the applications behind it, such as language or static versus dynamic content.

Ingress, or router, sharding should be used to serve more routes towards applications and help horizontally scale the routing tier.

For more information on Ingress sharding, see Configuring Ingress Controller sharding by using route labels and Configuring Ingress Controller sharding by using namespace labels.

You can modify the Ingress Controller deployment by using the information provided in Setting Ingress Controller thread count for threads and Ingress Controller configuration parameters for timeouts, and other tuning configurations in the Ingress Controller specification.

10.2.2. Configuring Ingress Controller liveness, readiness, and startup probes

Cluster administrators can configure the timeout values for the kubelet’s liveness, readiness, and startup probes for router deployments that are managed by the OpenShift Container Platform Ingress Controller (router). The liveness and readiness probes of the router use the default timeout value of 1 second, which is too brief when networking or runtime performance is severely degraded. Probe timeouts can cause unwanted router restarts that interrupt application connections. The ability to set larger timeout values can reduce the risk of unnecessary and unwanted restarts.

You can update the timeoutSeconds value on the livenessProbe, readinessProbe, and startupProbe parameters of the router container.

Parameter	Description
`livenessProbe`	The `livenessProbe` reports to the kubelet whether a pod is dead and needs to be restarted.
`readinessProbe`	The `readinessProbe` reports whether a pod is healthy or unhealthy. When the readiness probe reports an unhealthy pod, then the kubelet marks the pod as not ready to accept traffic. Subsequently, the endpoints for that pod are marked as not ready, and this status propagates to the kube-proxy. On cloud platforms with a configured load balancer, the kube-proxy communicates to the cloud load-balancer not to send traffic to the node with that pod.
`startupProbe`	The `startupProbe` gives the router pod up to 2 minutes to initialize before the kubelet begins sending the router liveness and readiness probes. This initialization time can prevent routers with many routes or endpoints from prematurely restarting.

Important

The timeout configuration option is an advanced tuning technique that can be used to work around issues. However, these issues should eventually be diagnosed and possibly a support case or Jira issue opened for any issues that causes probes to time out.

The following example demonstrates how you can directly patch the default router deployment to set a 5-second timeout for the liveness and readiness probes:

$ oc -n openshift-ingress patch deploy/router-default --type=strategic --patch='{"spec":{"template":{"spec":{"containers":[{"name":"router","livenessProbe":{"timeoutSeconds":5},"readinessProbe":{"timeoutSeconds":5}}]}}}}'

Verification

$ oc -n openshift-ingress describe deploy/router-default | grep -e Liveness: -e Readiness:
    Liveness:   http-get http://:1936/healthz delay=0s timeout=5s period=10s #success=1 #failure=3
    Readiness:  http-get http://:1936/healthz/ready delay=0s timeout=5s period=10s #success=1 #failure=3

10.2.3. Configuring HAProxy reload interval

When you update a route or an endpoint associated with a route, the OpenShift Container Platform router updates the configuration for HAProxy. Then, HAProxy reloads the updated configuration for those changes to take effect. When HAProxy reloads, it generates a new process that handles new connections using the updated configuration.

HAProxy keeps the old process running to handle existing connections until those connections are all closed. When old processes have long-lived connections, these processes can accumulate and consume resources.

The default minimum HAProxy reload interval is five seconds. You can configure an Ingress Controller using its spec.tuningOptions.reloadInterval field to set a longer minimum reload interval.

Warning

Setting a large value for the minimum HAProxy reload interval can cause latency in observing updates to routes and their endpoints. To lessen the risk, avoid setting a value larger than the tolerable latency for updates. The maximum value for HAProxy reload interval is 120 seconds.

Procedure

Change the minimum HAProxy reload interval of the default Ingress Controller to 15 seconds by running the following command:

$ oc -n openshift-ingress-operator patch ingresscontrollers/default --type=merge --patch='{"spec":{"tuningOptions":{"reloadInterval":"15s"}}}'

10.3. Optimizing networking

The OpenShift SDN uses OpenvSwitch, virtual extensible LAN (VXLAN) tunnels, OpenFlow rules, and iptables. This network can be tuned by using jumbo frames, multi-queue, and ethtool settings.

OVN-Kubernetes uses Generic Network Virtualization Encapsulation (Geneve) instead of VXLAN as the tunnel protocol. This network can be tuned by using network interface controller (NIC) offloads.

VXLAN provides benefits over VLANs, such as an increase in networks from 4096 to over 16 million, and layer 2 connectivity across physical networks. This allows for all pods behind a service to communicate with each other, even if they are running on different systems.

VXLAN encapsulates all tunneled traffic in user datagram protocol (UDP) packets. However, this leads to increased CPU utilization. Both these outer- and inner-packets are subject to normal checksumming rules to guarantee data is not corrupted during transit. Depending on CPU performance, this additional processing overhead can cause a reduction in throughput and increased latency when compared to traditional, non-overlay networks.

Cloud, VM, and bare metal CPU performance can be capable of handling much more than one Gbps network throughput. When using higher bandwidth links such as 10 or 40 Gbps, reduced performance can occur. This is a known issue in VXLAN-based environments and is not specific to containers or OpenShift Container Platform. Any network that relies on VXLAN tunnels will perform similarly because of the VXLAN implementation.

If you are looking to push beyond one Gbps, you can:

Evaluate network plugins that implement different routing techniques, such as border gateway protocol (BGP).
Use VXLAN-offload capable network adapters. VXLAN-offload moves the packet checksum calculation and associated CPU overhead off of the system CPU and onto dedicated hardware on the network adapter. This frees up CPU cycles for use by pods and applications, and allows users to utilize the full bandwidth of their network infrastructure.

VXLAN-offload does not reduce latency. However, CPU utilization is reduced even in latency tests.

10.3.1. Optimizing the MTU for your network

There are two important maximum transmission units (MTUs): the network interface controller (NIC) MTU and the cluster network MTU.

The NIC MTU is configured at the time of OpenShift Container Platform installation, and you can also change the cluster’s MTU as a Day 2 operation. See "Changing cluster network MTU" for more information. The MTU must be less than or equal to the maximum supported value of the NIC of your network. If you are optimizing for throughput, choose the largest possible value. If you are optimizing for lowest latency, choose a lower value.

The OpenShift SDN network plugin overlay MTU must be less than the NIC MTU by 50 bytes at a minimum. This accounts for the SDN overlay header. So, on a normal ethernet network, this should be set to 1450. On a jumbo frame ethernet network, this should be set to 8950. These values should be set automatically by the Cluster Network Operator based on the NIC’s configured MTU. Therefore, cluster administrators do not typically update these values. Amazon Web Services (AWS) and bare-metal environments support jumbo frame ethernet networks. This setting will help throughput, especially with transmission control protocol (TCP).

For OVN and Geneve, the MTU must be less than the NIC MTU by 100 bytes at a minimum.

Note

This 50 byte overlay header is relevant to the OpenShift SDN network plugin. Other SDN solutions might require the value to be more or less.

Additional resources

Changing cluster network MTU

10.3.2. Recommended practices for installing large scale clusters

When installing large clusters or scaling the cluster to larger node counts, set the cluster network cidr accordingly in your install-config.yaml file before you install the cluster:

networking:
  clusterNetwork:
  - cidr: 10.128.0.0/14
    hostPrefix: 23
  machineNetwork:
  - cidr: 10.0.0.0/16
  networkType: OVNKubernetes
  serviceNetwork:
  - 172.30.0.0/16

The default cluster network cidr 10.128.0.0/14 cannot be used if the cluster size is more than 500 nodes. It must be set to 10.128.0.0/12 or 10.128.0.0/10 to get to larger node counts beyond 500 nodes.

10.3.3. Impact of IPsec

Because encrypting and decrypting node hosts uses CPU power, performance is affected both in throughput and CPU usage on the nodes when encryption is enabled, regardless of the IP security system being used.

IPSec encrypts traffic at the IP payload level, before it hits the NIC, protecting fields that would otherwise be used for NIC offloading. This means that some NIC acceleration features might not be usable when IPSec is enabled and will lead to decreased throughput and increased CPU usage.

10.3.4. Additional resources

10.4. Optimizing CPU usage with mount namespace encapsulation

You can optimize CPU usage in OpenShift Container Platform clusters by using mount namespace encapsulation to provide a private namespace for kubelet and CRI-O processes. This reduces the cluster CPU resources used by systemd with no difference in functionality.

Important

Mount namespace encapsulation is a Technology Preview feature only. Technology Preview features are not supported with Red Hat production service level agreements (SLAs) and might not be functionally complete. Red Hat does not recommend using them in production. These features provide early access to upcoming product features, enabling customers to test functionality and provide feedback during the development process.

For more information about the support scope of Red Hat Technology Preview features, see Technology Preview Features Support Scope.

10.4.1. Encapsulating mount namespaces

Mount namespaces are used to isolate mount points so that processes in different namespaces cannot view each others' files. Encapsulation is the process of moving Kubernetes mount namespaces to an alternative location where they will not be constantly scanned by the host operating system.

The host operating system uses systemd to constantly scan all mount namespaces: both the standard Linux mounts and the numerous mounts that Kubernetes uses to operate. The current implementation of kubelet and CRI-O both use the top-level namespace for all container runtime and kubelet mount points. However, encapsulating these container-specific mount points in a private namespace reduces systemd overhead with no difference in functionality. Using a separate mount namespace for both CRI-O and kubelet can encapsulate container-specific mounts from any systemd or other host operating system interaction.

This ability to potentially achieve major CPU optimization is now available to all OpenShift Container Platform administrators. Encapsulation can also improve security by storing Kubernetes-specific mount points in a location safe from inspection by unprivileged users.

The following diagrams illustrate a Kubernetes installation before and after encapsulation. Both scenarios show example containers which have mount propagation settings of bidirectional, host-to-container, and none.

Here we see systemd, host operating system processes, kubelet, and the container runtime sharing a single mount namespace.

systemd, host operating system processes, kubelet, and the container runtime each have access to and visibility of all mount points.
Container 1, configured with bidirectional mount propagation, can access systemd and host mounts, kubelet and CRI-O mounts. A mount originating in Container 1, such as /run/a is visible to systemd, host operating system processes, kubelet, container runtime, and other containers with host-to-container or bidirectional mount propagation configured (as in Container 2).
Container 2, configured with host-to-container mount propagation, can access systemd and host mounts, kubelet and CRI-O mounts. A mount originating in Container 2, such as /run/b, is not visible to any other context.
Container 3, configured with no mount propagation, has no visibility of external mount points. A mount originating in Container 3, such as /run/c, is not visible to any other context.

The following diagram illustrates the system state after encapsulation.

The main systemd process is no longer devoted to unnecessary scanning of Kubernetes-specific mount points. It only monitors systemd-specific and host mount points.
The host operating system processes can access only the systemd and host mount points.
Using a separate mount namespace for both CRI-O and kubelet completely separates all container-specific mounts away from any systemd or other host operating system interaction whatsoever.
The behavior of Container 1 is unchanged, except a mount it creates such as /run/a is no longer visible to systemd or host operating system processes. It is still visible to kubelet, CRI-O, and other containers with host-to-container or bidirectional mount propagation configured (like Container 2).
The behavior of Container 2 and Container 3 is unchanged.

10.4.2. Configuring mount namespace encapsulation

You can configure mount namespace encapsulation so that a cluster runs with less resource overhead.

Note

Mount namespace encapsulation is a Technology Preview feature and it is disabled by default. To use it, you must enable the feature manually.

Prerequisites

You have installed the OpenShift CLI (oc).
You have logged in as a user with cluster-admin privileges.

Procedure

Create a file called mount_namespace_config.yaml with the following YAML:

apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: master
  name: 99-kubens-master
spec:
  config:
    ignition:
      version: 3.2.0
    systemd:
      units:
      - enabled: true
        name: kubens.service
---
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: worker
  name: 99-kubens-worker
spec:
  config:
    ignition:
      version: 3.2.0
    systemd:
      units:
      - enabled: true
        name: kubens.service

Apply the mount namespace MachineConfig CR by running the following command:

$ oc apply -f mount_namespace_config.yaml

Example output

machineconfig.machineconfiguration.openshift.io/99-kubens-master created
machineconfig.machineconfiguration.openshift.io/99-kubens-worker created

The MachineConfig CR can take up to 30 minutes to finish being applied in the cluster. You can check the status of the MachineConfig CR by running the following command:

$ oc get mcp

Example output

NAME     CONFIG                                             UPDATED   UPDATING   DEGRADED   MACHINECOUNT   READYMACHINECOUNT   UPDATEDMACHINECOUNT   DEGRADEDMACHINECOUNT   AGE
master   rendered-master-03d4bc4befb0f4ed3566a2c8f7636751   False     True       False      3              0                   0                     0                      45m
worker   rendered-worker-10577f6ab0117ed1825f8af2ac687ddf   False     True       False      3              1                   1

Wait for the MachineConfig CR to be applied successfully across all control plane and worker nodes after running the following command:

$ oc wait --for=condition=Updated mcp --all --timeout=30m

Example output

machineconfigpool.machineconfiguration.openshift.io/master condition met
machineconfigpool.machineconfiguration.openshift.io/worker condition met

Verification

To verify encapsulation for a cluster host, run the following commands:

Open a debug shell to the cluster host:
```
$ oc debug node/<node_name>
```
Open a chroot session:
```
sh-4.4# chroot /host
```
Check the systemd mount namespace:
```
sh-4.4# readlink /proc/1/ns/mnt
```
Example output
```
mnt:[4026531953]
```

Check kubelet mount namespace:

sh-4.4# readlink /proc/$(pgrep kubelet)/ns/mnt

Example output

mnt:[4026531840]

Check the CRI-O mount namespace:

sh-4.4# readlink /proc/$(pgrep crio)/ns/mnt

Example output

mnt:[4026531840]

These commands return the mount namespaces associated with systemd, kubelet, and the container runtime. In OpenShift Container Platform, the container runtime is CRI-O.

Encapsulation is in effect if systemd is in a different mount namespace to kubelet and CRI-O as in the above example. Encapsulation is not in effect if all three processes are in the same mount namespace.

10.4.3. Inspecting encapsulated namespaces

You can inspect Kubernetes-specific mount points in the cluster host operating system for debugging or auditing purposes by using the kubensenter script that is available in Red Hat Enterprise Linux CoreOS (RHCOS).

SSH shell sessions to the cluster host are in the default namespace. To inspect Kubernetes-specific mount points in an SSH shell prompt, you need to run the kubensenter script as root. The kubensenter script is aware of the state of the mount encapsulation, and is safe to run even if encapsulation is not enabled.

Note

oc debug remote shell sessions start inside the Kubernetes namespace by default. You do not need to run kubensenter to inspect mount points when you use oc debug.

If the encapsulation feature is not enabled, the kubensenter findmnt and findmnt commands return the same output, regardless of whether they are run in an oc debug session or in an SSH shell prompt.

Prerequisites

You have installed the OpenShift CLI (oc).
You have logged in as a user with cluster-admin privileges.
You have configured SSH access to the cluster host.

Procedure

Open a remote SSH shell to the cluster host. For example:
```
$ ssh core@<node_name>
```

Run commands using the provided kubensenter script as the root user. To run a single command inside the Kubernetes namespace, provide the command and any arguments to the kubensenter script. For example, to run the findmnt command inside the Kubernetes namespace, run the following command:

[core@control-plane-1 ~]$ sudo kubensenter findmnt

Example output

kubensenter: Autodetect: kubens.service namespace found at /run/kubens/mnt
TARGET                                SOURCE                 FSTYPE     OPTIONS
/                                     /dev/sda4[/ostree/deploy/rhcos/deploy/32074f0e8e5ec453e56f5a8a7bc9347eaa4172349ceab9c22b709d9d71a3f4b0.0]
|                                                            xfs        rw,relatime,seclabel,attr2,inode64,logbufs=8,logbsize=32k,prjquota
                                      shm                    tmpfs
...

To start a new interactive shell inside the Kubernetes namespace, run the kubensenter script without any arguments:
```
[core@control-plane-1 ~]$ sudo kubensenter
```
Example output
```
kubensenter: Autodetect: kubens.service namespace found at /run/kubens/mnt
```

10.4.4. Running additional services in the encapsulated namespace

Any monitoring tool that relies on the ability to run in the host operating system and have visibility of mount points created by kubelet, CRI-O, or containers themselves, must enter the container mount namespace to see these mount points. The kubensenter script that is provided with OpenShift Container Platform executes another command inside the Kubernetes mount point and can be used to adapt any existing tools.

The kubensenter script is aware of the state of the mount encapsulation feature status, and is safe to run even if encapsulation is not enabled. In that case the script executes the provided command in the default mount namespace.

For example, if a systemd service needs to run inside the new Kubernetes mount namespace, edit the service file and use the ExecStart= command line with kubensenter.

[Unit]
Description=Example service
[Service]
ExecStart=/usr/bin/kubensenter /path/to/original/command arg1 arg2

10.4.5. Additional resources

Chapter 11. Managing bare metal hosts

When you install OpenShift Container Platform on a bare metal cluster, you can provision and manage bare metal nodes using machine and machineset custom resources (CRs) for bare metal hosts that exist in the cluster.

11.1. About bare metal hosts and nodes

To provision a Red Hat Enterprise Linux CoreOS (RHCOS) bare metal host as a node in your cluster, first create a MachineSet custom resource (CR) object that corresponds to the bare metal host hardware. Bare metal host compute machine sets describe infrastructure components specific to your configuration. You apply specific Kubernetes labels to these compute machine sets and then update the infrastructure components to run on only those machines.

Machine CR’s are created automatically when you scale up the relevant MachineSet containing a metal3.io/autoscale-to-hosts annotation. OpenShift Container Platform uses Machine CR’s to provision the bare metal node that corresponds to the host as specified in the MachineSet CR.

11.2. Maintaining bare metal hosts

You can maintain the details of the bare metal hosts in your cluster from the OpenShift Container Platform web console. Navigate to Compute → Bare Metal Hosts, and select a task from the Actions drop down menu. Here you can manage items such as BMC details, boot MAC address for the host, enable power management, and so on. You can also review the details of the network interfaces and drives for the host.

You can move a bare metal host into maintenance mode. When you move a host into maintenance mode, the scheduler moves all managed workloads off the corresponding bare metal node. No new workloads are scheduled while in maintenance mode.

You can deprovision a bare metal host in the web console. Deprovisioning a host does the following actions:

Annotates the bare metal host CR with cluster.k8s.io/delete-machine: true
Scales down the related compute machine set

Note

Powering off the host without first moving the daemon set and unmanaged static pods to another node can cause service disruption and loss of data.

Additional resources

Adding compute machines to bare metal

11.2.1. Adding a bare metal host to the cluster using the web console

You can add bare metal hosts to the cluster in the web console.

Prerequisites

Install an RHCOS cluster on bare metal.
Log in as a user with cluster-admin privileges.

Procedure

In the web console, navigate to Compute → Bare Metal Hosts.
Select Add Host → New with Dialog.
Specify a unique name for the new bare metal host.
Set the Boot MAC address.
Set the Baseboard Management Console (BMC) Address.
Enter the user credentials for the host’s baseboard management controller (BMC).
Select to power on the host after creation, and select Create.
Scale up the number of replicas to match the number of available bare metal hosts. Navigate to Compute → MachineSets, and increase the number of machine replicas in the cluster by selecting Edit Machine count from the Actions drop-down menu.

Note

You can also manage the number of bare metal nodes using the oc scale command and the appropriate bare metal compute machine set.

11.2.2. Adding a bare metal host to the cluster using YAML in the web console

You can add bare metal hosts to the cluster in the web console using a YAML file that describes the bare metal host.

Prerequisites

Install a RHCOS compute machine on bare metal infrastructure for use in the cluster.
Log in as a user with cluster-admin privileges.
Create a Secret CR for the bare metal host.

Procedure

In the web console, navigate to Compute → Bare Metal Hosts.
Select Add Host → New from YAML.
Copy and paste the below YAML, modifying the relevant fields with the details of your host:
```
apiVersion: metal3.io/v1alpha1
kind: BareMetalHost
metadata:
  name: <bare_metal_host_name>
spec:
  online: true
  bmc:
    address: <bmc_address>
    credentialsName: <secret_credentials_name>  1
    disableCertificateVerification: True 2
  bootMACAddress: <host_boot_mac_address>
```
1
credentialsName must reference a valid Secret CR. The baremetal-operator cannot manage the bare metal host without a valid Secret referenced in the credentialsName. For more information about secrets and how to create them, see Understanding secrets.
2
Setting disableCertificateVerification to true disables TLS host validation between the cluster and the baseboard management controller (BMC).
Select Create to save the YAML and create the new bare metal host.
Scale up the number of replicas to match the number of available bare metal hosts. Navigate to Compute → MachineSets, and increase the number of machines in the cluster by selecting Edit Machine count from the Actions drop-down menu.
Note
You can also manage the number of bare metal nodes using the oc scale command and the appropriate bare metal compute machine set.

11.2.3. Automatically scaling machines to the number of available bare metal hosts

To automatically create the number of Machine objects that matches the number of available BareMetalHost objects, add a metal3.io/autoscale-to-hosts annotation to the MachineSet object.

Prerequisites

Install RHCOS bare metal compute machines for use in the cluster, and create corresponding BareMetalHost objects.
Install the OpenShift Container Platform CLI (oc).
Log in as a user with cluster-admin privileges.

Procedure

Annotate the compute machine set that you want to configure for automatic scaling by adding the metal3.io/autoscale-to-hosts annotation. Replace <machineset> with the name of the compute machine set.
```
$ oc annotate machineset <machineset> -n openshift-machine-api 'metal3.io/autoscale-to-hosts=<any_value>'
```
Wait for the new scaled machines to start.

Note

When you use a BareMetalHost object to create a machine in the cluster and labels or selectors are subsequently changed on the BareMetalHost, the BareMetalHost object continues be counted against the MachineSet that the Machine object was created from.

11.2.4. Removing bare metal hosts from the provisioner node

In certain circumstances, you might want to temporarily remove bare metal hosts from the provisioner node. For example, during provisioning when a bare metal host reboot is triggered by using the OpenShift Container Platform administration console or as a result of a Machine Config Pool update, OpenShift Container Platform logs into the integrated Dell Remote Access Controller (iDrac) and issues a delete of the job queue.

To prevent the management of the number of Machine objects that matches the number of available BareMetalHost objects, add a baremetalhost.metal3.io/detached annotation to the MachineSet object.

Note

This annotation has an effect for only BareMetalHost objects that are in either Provisioned, ExternallyProvisioned or Ready/Available state.

Prerequisites

Install RHCOS bare metal compute machines for use in the cluster and create corresponding BareMetalHost objects.
Install the OpenShift Container Platform CLI (oc).
Log in as a user with cluster-admin privileges.

Procedure

Annotate the compute machine set that you want to remove from the provisioner node by adding the baremetalhost.metal3.io/detached annotation.
```
$ oc annotate machineset <machineset> -n openshift-machine-api 'baremetalhost.metal3.io/detached'
```
Wait for the new machines to start.
Note
When you use a BareMetalHost object to create a machine in the cluster and labels or selectors are subsequently changed on the BareMetalHost, the BareMetalHost object continues be counted against the MachineSet that the Machine object was created from.
In the provisioning use case, remove the annotation after the reboot is complete by using the following command:
```
$ oc annotate machineset <machineset> -n openshift-machine-api 'baremetalhost.metal3.io/detached-'
```

Additional resources

Chapter 12. Monitoring bare-metal events with the Bare Metal Event Relay

Important

Bare Metal Event Relay is a Technology Preview feature only. Technology Preview features are not supported with Red Hat production service level agreements (SLAs) and might not be functionally complete. Red Hat does not recommend using them in production. These features provide early access to upcoming product features, enabling customers to test functionality and provide feedback during the development process.

For more information about the support scope of Red Hat Technology Preview features, see Technology Preview Features Support Scope.

12.1. About bare-metal events

Use the Bare Metal Event Relay to subscribe applications that run in your OpenShift Container Platform cluster to events that are generated on the underlying bare-metal host. The Redfish service publishes events on a node and transmits them on an advanced message queue to subscribed applications.

Bare-metal events are based on the open Redfish standard that is developed under the guidance of the Distributed Management Task Force (DMTF). Redfish provides a secure industry-standard protocol with a REST API. The protocol is used for the management of distributed, converged or software-defined resources and infrastructure.

Hardware-related events published through Redfish includes:

Breaches of temperature limits
Server status
Fan status

Begin using bare-metal events by deploying the Bare Metal Event Relay Operator and subscribing your application to the service. The Bare Metal Event Relay Operator installs and manages the lifecycle of the Redfish bare-metal event service.

Note

The Bare Metal Event Relay works only with Redfish-capable devices on single-node clusters provisioned on bare-metal infrastructure.

12.2. How bare-metal events work

The Bare Metal Event Relay enables applications running on bare-metal clusters to respond quickly to Redfish hardware changes and failures such as breaches of temperature thresholds, fan failure, disk loss, power outages, and memory failure. These hardware events are delivered using an HTTP transport or AMQP mechanism. The latency of the messaging service is between 10 to 20 milliseconds.

The Bare Metal Event Relay provides a publish-subscribe service for the hardware events. Applications can use a REST API to subscribe to the events. The Bare Metal Event Relay supports hardware that complies with Redfish OpenAPI v1.8 or later.

12.2.1. Bare Metal Event Relay data flow

The following figure illustrates an example bare-metal events data flow:

Figure 12.1. Bare Metal Event Relay data flow

12.2.1.1. Operator-managed pod

The Operator uses custom resources to manage the pod containing the Bare Metal Event Relay and its components using the HardwareEvent CR.

12.2.1.2. Bare Metal Event Relay

At startup, the Bare Metal Event Relay queries the Redfish API and downloads all the message registries, including custom registries. The Bare Metal Event Relay then begins to receive subscribed events from the Redfish hardware.

12.2.1.3. Cloud native event

Cloud native events (CNE) is a REST API specification for defining the format of event data.

12.2.1.4. CNCF CloudEvents

CloudEvents is a vendor-neutral specification developed by the Cloud Native Computing Foundation (CNCF) for defining the format of event data.

12.2.1.5. HTTP transport or AMQP dispatch router

The HTTP transport or AMQP dispatch router is responsible for the message delivery service between publisher and subscriber.

Note

HTTP transport is the default transport for PTP and bare-metal events. Use HTTP transport instead of AMQP for PTP and bare-metal events where possible. AMQ Interconnect is EOL from 30 June 2024. Extended life cycle support (ELS) for AMQ Interconnect ends 29 November 2029. For more information see, Red Hat AMQ Interconnect support status.

12.2.1.6. Cloud event proxy sidecar

The cloud event proxy sidecar container image is based on the O-RAN API specification and provides a publish-subscribe event framework for hardware events.

12.2.2. Redfish message parsing service

In addition to handling Redfish events, the Bare Metal Event Relay provides message parsing for events without a Message property. The proxy downloads all the Redfish message registries including vendor specific registries from the hardware when it starts. If an event does not contain a Message property, the proxy uses the Redfish message registries to construct the Message and Resolution properties and add them to the event before passing the event to the cloud events framework. This service allows Redfish events to have smaller message size and lower transmission latency.

12.2.3. Installing the Bare Metal Event Relay using the CLI

As a cluster administrator, you can install the Bare Metal Event Relay Operator by using the CLI.

Prerequisites

A cluster that is installed on bare-metal hardware with nodes that have a RedFish-enabled Baseboard Management Controller (BMC).
Install the OpenShift CLI (oc).
Log in as a user with cluster-admin privileges.

Procedure

Create a namespace for the Bare Metal Event Relay.

Save the following YAML in the bare-metal-events-namespace.yaml file:

apiVersion: v1
kind: Namespace
metadata:
  name: openshift-bare-metal-events
  labels:
    name: openshift-bare-metal-events
    openshift.io/cluster-monitoring: "true"

Create the Namespace CR:

$ oc create -f bare-metal-events-namespace.yaml

Create an Operator group for the Bare Metal Event Relay Operator.

Save the following YAML in the bare-metal-events-operatorgroup.yaml file:

apiVersion: operators.coreos.com/v1
kind: OperatorGroup
metadata:
  name: bare-metal-event-relay-group
  namespace: openshift-bare-metal-events
spec:
  targetNamespaces:
  - openshift-bare-metal-events

Create the OperatorGroup CR:

$ oc create -f bare-metal-events-operatorgroup.yaml

Subscribe to the Bare Metal Event Relay.

Save the following YAML in the bare-metal-events-sub.yaml file:

apiVersion: operators.coreos.com/v1alpha1
kind: Subscription
metadata:
  name: bare-metal-event-relay-subscription
  namespace: openshift-bare-metal-events
spec:
  channel: "stable"
  name: bare-metal-event-relay
  source: redhat-operators
  sourceNamespace: openshift-marketplace

Create the Subscription CR:

$ oc create -f bare-metal-events-sub.yaml

Verification

To verify that the Bare Metal Event Relay Operator is installed, run the following command:

$ oc get csv -n openshift-bare-metal-events -o custom-columns=Name:.metadata.name,Phase:.status.phase

12.2.4. Installing the Bare Metal Event Relay using the web console

As a cluster administrator, you can install the Bare Metal Event Relay Operator using the web console.

Prerequisites

A cluster that is installed on bare-metal hardware with nodes that have a RedFish-enabled Baseboard Management Controller (BMC).
Log in as a user with cluster-admin privileges.

Procedure

Install the Bare Metal Event Relay using the OpenShift Container Platform web console:
1. In the OpenShift Container Platform web console, click Operators → OperatorHub.
2. Choose Bare Metal Event Relay from the list of available Operators, and then click Install.
3. On the Install Operator page, select or create a Namespace, select openshift-bare-metal-events, and then click Install.

Verification

Optional: You can verify that the Operator installed successfully by performing the following check:

Switch to the Operators → Installed Operators page.
Ensure that Bare Metal Event Relay is listed in the project with a Status of InstallSucceeded.
Note
During installation an Operator might display a Failed status. If the installation later succeeds with an InstallSucceeded message, you can ignore the Failed message.

If the Operator does not appear as installed, to troubleshoot further:

Go to the Operators → Installed Operators page and inspect the Operator Subscriptions and Install Plans tabs for any failure or errors under Status.
Go to the Workloads → Pods page and check the logs for pods in the project namespace.

12.3. Installing the AMQ messaging bus

To pass Redfish bare-metal event notifications between publisher and subscriber on a node, you can install and configure an AMQ messaging bus to run locally on the node. You do this by installing the AMQ Interconnect Operator for use in the cluster.

Note

Prerequisites

Install the OpenShift Container Platform CLI (oc).
Log in as a user with cluster-admin privileges.

Procedure

Install the AMQ Interconnect Operator to its own amq-interconnect namespace. See Installing the AMQ Interconnect Operator.

Verification

Verify that the AMQ Interconnect Operator is available and the required pods are running:

$ oc get pods -n amq-interconnect

Example output

NAME                                    READY   STATUS    RESTARTS   AGE
amq-interconnect-645db76c76-k8ghs       1/1     Running   0          23h
interconnect-operator-5cb5fc7cc-4v7qm   1/1     Running   0          23h

Verify that the required bare-metal-event-relay bare-metal event producer pod is running in the openshift-bare-metal-events namespace:

$ oc get pods -n openshift-bare-metal-events

Example output

NAME                                                            READY   STATUS    RESTARTS   AGE
hw-event-proxy-operator-controller-manager-74d5649b7c-dzgtl     2/2     Running   0          25s

12.4. Subscribing to Redfish BMC bare-metal events for a cluster node

You can subscribe to Redfish BMC events generated on a node in your cluster by creating a BMCEventSubscription custom resource (CR) for the node, creating a HardwareEvent CR for the event, and creating a Secret CR for the BMC.

12.4.1. Subscribing to bare-metal events

You can configure the baseboard management controller (BMC) to send bare-metal events to subscribed applications running in an OpenShift Container Platform cluster. Example Redfish bare-metal events include an increase in device temperature, or removal of a device. You subscribe applications to bare-metal events using a REST API.

Important

You can only create a BMCEventSubscription custom resource (CR) for physical hardware that supports Redfish and has a vendor interface set to redfish or idrac-redfish.

Note

Use the BMCEventSubscription CR to subscribe to predefined Redfish events. The Redfish standard does not provide an option to create specific alerts and thresholds. For example, to receive an alert event when an enclosure’s temperature exceeds 40° Celsius, you must manually configure the event according to the vendor’s recommendations.

Perform the following procedure to subscribe to bare-metal events for the node using a BMCEventSubscription CR.

Prerequisites

Install the OpenShift CLI (oc).
Log in as a user with cluster-admin privileges.
Get the user name and password for the BMC.
Deploy a bare-metal node with a Redfish-enabled Baseboard Management Controller (BMC) in your cluster, and enable Redfish events on the BMC.
Note
Enabling Redfish events on specific hardware is outside the scope of this information. For more information about enabling Redfish events for your specific hardware, consult the BMC manufacturer documentation.

Procedure

Confirm that the node hardware has the Redfish EventService enabled by running the following curl command:

$ curl https://<bmc_ip_address>/redfish/v1/EventService --insecure -H 'Content-Type: application/json' -u "<bmc_username>:<password>"

where:

bmc_ip_address: is the IP address of the BMC where the Redfish events are generated.

Example output

{
   "@odata.context": "/redfish/v1/$metadata#EventService.EventService",
   "@odata.id": "/redfish/v1/EventService",
   "@odata.type": "#EventService.v1_0_2.EventService",
   "Actions": {
      "#EventService.SubmitTestEvent": {
         "EventType@Redfish.AllowableValues": ["StatusChange", "ResourceUpdated", "ResourceAdded", "ResourceRemoved", "Alert"],
         "target": "/redfish/v1/EventService/Actions/EventService.SubmitTestEvent"
      }
   },
   "DeliveryRetryAttempts": 3,
   "DeliveryRetryIntervalSeconds": 30,
   "Description": "Event Service represents the properties for the service",
   "EventTypesForSubscription": ["StatusChange", "ResourceUpdated", "ResourceAdded", "ResourceRemoved", "Alert"],
   "EventTypesForSubscription@odata.count": 5,
   "Id": "EventService",
   "Name": "Event Service",
   "ServiceEnabled": true,
   "Status": {
      "Health": "OK",
      "HealthRollup": "OK",
      "State": "Enabled"
   },
   "Subscriptions": {
      "@odata.id": "/redfish/v1/EventService/Subscriptions"
   }
}

Get the Bare Metal Event Relay service route for the cluster by running the following command:

$ oc get route -n openshift-bare-metal-events

Example output

NAME            HOST/PORT   PATH                                                                    SERVICES                 PORT   TERMINATION   WILDCARD
hw-event-proxy              hw-event-proxy-openshift-bare-metal-events.apps.compute-1.example.com   hw-event-proxy-service   9087   edge          None

Create a BMCEventSubscription resource to subscribe to the Redfish events:
1. Save the following YAML in the bmc_sub.yaml file:
```
apiVersion: metal3.io/v1alpha1
kind: BMCEventSubscription
metadata:
  name: sub-01
  namespace: openshift-machine-api
spec:
   hostName: <hostname> 1
   destination: <proxy_service_url> 2
   context: ''
```
  1
  Specifies the name or UUID of the worker node where the Redfish events are generated.
  2
  Specifies the bare-metal event proxy service, for example, https://hw-event-proxy-openshift-bare-metal-events.apps.compute-1.example.com/webhook.
2. Create the BMCEventSubscription CR:
```
$ oc create -f bmc_sub.yaml
```
Optional: To delete the BMC event subscription, run the following command:
```
$ oc delete -f bmc_sub.yaml
```

Optional: To manually create a Redfish event subscription without creating a BMCEventSubscription CR, run the following curl command, specifying the BMC username and password.

$ curl -i -k -X POST -H "Content-Type: application/json"  -d '{"Destination": "https://<proxy_service_url>", "Protocol" : "Redfish", "EventTypes": ["Alert"], "Context": "root"}' -u <bmc_username>:<password> 'https://<bmc_ip_address>/redfish/v1/EventService/Subscriptions' –v

where:

proxy_service_url: is the bare-metal event proxy service, for example, https://hw-event-proxy-openshift-bare-metal-events.apps.compute-1.example.com/webhook.

bmc_ip_address: is the IP address of the BMC where the Redfish events are generated.

Example output

HTTP/1.1 201 Created
Server: AMI MegaRAC Redfish Service
Location: /redfish/v1/EventService/Subscriptions/1
Allow: GET, POST
Access-Control-Allow-Origin: *
Access-Control-Expose-Headers: X-Auth-Token
Access-Control-Allow-Headers: X-Auth-Token
Access-Control-Allow-Credentials: true
Cache-Control: no-cache, must-revalidate
Link: <http://redfish.dmtf.org/schemas/v1/EventDestination.v1_6_0.json>; rel=describedby
Link: <http://redfish.dmtf.org/schemas/v1/EventDestination.v1_6_0.json>
Link: </redfish/v1/EventService/Subscriptions>; path=
ETag: "1651135676"
Content-Type: application/json; charset=UTF-8
OData-Version: 4.0
Content-Length: 614
Date: Thu, 28 Apr 2022 08:47:57 GMT

12.4.2. Querying Redfish bare-metal event subscriptions with curl

Some hardware vendors limit the amount of Redfish hardware event subscriptions. You can query the number of Redfish event subscriptions by using curl.

Prerequisites

Get the user name and password for the BMC.
Deploy a bare-metal node with a Redfish-enabled Baseboard Management Controller (BMC) in your cluster, and enable Redfish hardware events on the BMC.

Procedure

Check the current subscriptions for the BMC by running the following curl command:

$ curl --globoff -H "Content-Type: application/json" -k -X GET --user <bmc_username>:<password> https://<bmc_ip_address>/redfish/v1/EventService/Subscriptions

where:

bmc_ip_address: is the IP address of the BMC where the Redfish events are generated.

Example output

% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 435 100 435 0 0 399 0 0:00:01 0:00:01 --:--:-- 399
{
  "@odata.context": "/redfish/v1/$metadata#EventDestinationCollection.EventDestinationCollection",
  "@odata.etag": ""
  1651137375 "",
  "@odata.id": "/redfish/v1/EventService/Subscriptions",
  "@odata.type": "#EventDestinationCollection.EventDestinationCollection",
  "Description": "Collection for Event Subscriptions",
  "Members": [
  {
    "@odata.id": "/redfish/v1/EventService/Subscriptions/1"
  }],
  "Members@odata.count": 1,
  "Name": "Event Subscriptions Collection"
}

In this example, a single subscription is configured: /redfish/v1/EventService/Subscriptions/1.

Optional: To remove the /redfish/v1/EventService/Subscriptions/1 subscription with curl, run the following command, specifying the BMC username and password:
```
$ curl --globoff -L -w "%{http_code} %{url_effective}\n" -k -u <bmc_username>:<password >-H "Content-Type: application/json" -d '{}' -X DELETE https://<bmc_ip_address>/redfish/v1/EventService/Subscriptions/1
```
where:
bmc_ip_address
is the IP address of the BMC where the Redfish events are generated.

12.4.3. Creating the bare-metal event and Secret CRs

To start using bare-metal events, create the HardwareEvent custom resource (CR) for the host where the Redfish hardware is present. Hardware events and faults are reported in the hw-event-proxy logs.

Prerequisites

You have installed the OpenShift Container Platform CLI (oc).
You have logged in as a user with cluster-admin privileges.
You have installed the Bare Metal Event Relay.
You have created a BMCEventSubscription CR for the BMC Redfish hardware.

Procedure

Create the HardwareEvent custom resource (CR):
Note
Multiple HardwareEvent resources are not permitted.
1. Save the following YAML in the hw-event.yaml file:
```
apiVersion: "event.redhat-cne.org/v1alpha1"
kind: "HardwareEvent"
metadata:
  name: "hardware-event"
spec:
  nodeSelector:
    node-role.kubernetes.io/hw-event: "" 1
  logLevel: "debug" 2
  msgParserTimeout: "10" 3
```
  1
  Required. Use the nodeSelector field to target nodes with the specified label, for example, node-role.kubernetes.io/hw-event: "".
  Note
  In OpenShift Container Platform 4.13 or later, you do not need to set the spec.transportHost field in the HardwareEvent resource when you use HTTP transport for bare-metal events. Set transportHost only when you use AMQP transport for bare-metal events.
  2
  Optional. The default value is debug. Sets the log level in hw-event-proxy logs. The following log levels are available: fatal, error, warning, info, debug, trace.
  3
  Optional. Sets the timeout value in milliseconds for the Message Parser. If a message parsing request is not responded to within the timeout duration, the original hardware event message is passed to the cloud native event framework. The default value is 10.
2. Apply the HardwareEvent CR in the cluster:
```
$ oc create -f hardware-event.yaml
```
Create a BMC username and password Secret CR that enables the hardware events proxy to access the Redfish message registry for the bare-metal host.
1. Save the following YAML in the hw-event-bmc-secret.yaml file:
```
apiVersion: v1
kind: Secret
metadata:
  name: redfish-basic-auth
type: Opaque
stringData: 1
  username: <bmc_username>
  password: <bmc_password>
  # BMC host DNS or IP address
  hostaddr: <bmc_host_ip_address>
```
  1
  Enter plain text values for the various items under stringData.
2. Create the Secret CR:
```
$ oc create -f hw-event-bmc-secret.yaml
```

Additional resources

Persistent storage using local volumes

12.5. Subscribing applications to bare-metal events REST API reference

Use the bare-metal events REST API to subscribe an application to the bare-metal events that are generated on the parent node.

Subscribe applications to Redfish events by using the resource address /cluster/node/<node_name>/redfish/event, where <node_name> is the cluster node running the application.

Deploy your cloud-event-consumer application container and cloud-event-proxy sidecar container in a separate application pod. The cloud-event-consumer application subscribes to the cloud-event-proxy container in the application pod.

Use the following API endpoints to subscribe the cloud-event-consumer application to Redfish events posted by the cloud-event-proxy container at http://localhost:8089/api/ocloudNotifications/v1/ in the application pod:

/api/ocloudNotifications/v1/subscriptions
- POST: Creates a new subscription
- GET: Retrieves a list of subscriptions
/api/ocloudNotifications/v1/subscriptions/<subscription_id>
- PUT: Creates a new status ping request for the specified subscription ID
/api/ocloudNotifications/v1/health
- GET: Returns the health status of ocloudNotifications API

Note

9089 is the default port for the cloud-event-consumer container deployed in the application pod. You can configure a different port for your application as required.

api/ocloudNotifications/v1/subscriptions

HTTP method

GET api/ocloudNotifications/v1/subscriptions

Description

Returns a list of subscriptions. If subscriptions exist, a 200 OK status code is returned along with the list of subscriptions.

Example API response

[
 {
  "id": "ca11ab76-86f9-428c-8d3a-666c24e34d32",
  "endpointUri": "http://localhost:9089/api/ocloudNotifications/v1/dummy",
  "uriLocation": "http://localhost:8089/api/ocloudNotifications/v1/subscriptions/ca11ab76-86f9-428c-8d3a-666c24e34d32",
  "resource": "/cluster/node/openshift-worker-0.openshift.example.com/redfish/event"
 }
]

HTTP method

POST api/ocloudNotifications/v1/subscriptions

Description

Creates a new subscription. If a subscription is successfully created, or if it already exists, a 201 Created status code is returned.

Table 12.1. Query parameters
Parameter	Type
subscription	data

Example payload

{
  "uriLocation": "http://localhost:8089/api/ocloudNotifications/v1/subscriptions",
  "resource": "/cluster/node/openshift-worker-0.openshift.example.com/redfish/event"
}

api/ocloudNotifications/v1/subscriptions/<subscription_id>

HTTP method

GET api/ocloudNotifications/v1/subscriptions/<subscription_id>

Description

Returns details for the subscription with ID <subscription_id>

Table 12.2. Query parameters
Parameter	Type
`<subscription_id>`	string

Example API response

{
  "id":"ca11ab76-86f9-428c-8d3a-666c24e34d32",
  "endpointUri":"http://localhost:9089/api/ocloudNotifications/v1/dummy",
  "uriLocation":"http://localhost:8089/api/ocloudNotifications/v1/subscriptions/ca11ab76-86f9-428c-8d3a-666c24e34d32",
  "resource":"/cluster/node/openshift-worker-0.openshift.example.com/redfish/event"
}

api/ocloudNotifications/v1/health/

HTTP method

GET api/ocloudNotifications/v1/health/

Description

Returns the health status for the ocloudNotifications REST API.

Example API response

OK

12.6. Migrating consumer applications to use HTTP transport for PTP or bare-metal events

If you have previously deployed PTP or bare-metal events consumer applications, you need to update the applications to use HTTP message transport.

Prerequisites

You have installed the OpenShift CLI (oc).
You have logged in as a user with cluster-admin privileges.
You have updated the PTP Operator or Bare Metal Event Relay to version 4.13+ which uses HTTP transport by default.

Procedure

Update your events consumer application to use HTTP transport. Set the http-event-publishers variable for the cloud event sidecar deployment.
For example, in a cluster with PTP events configured, the following YAML snippet illustrates a cloud event sidecar deployment:
```
containers:
  - name: cloud-event-sidecar
    image: cloud-event-sidecar
    args:
      - "--metrics-addr=127.0.0.1:9091"
      - "--store-path=/store"
      - "--transport-host=consumer-events-subscription-service.cloud-events.svc.cluster.local:9043"
      - "--http-event-publishers=ptp-event-publisher-service-NODE_NAME.openshift-ptp.svc.cluster.local:9043" 1
      - "--api-port=8089"
```
1
The PTP Operator automatically resolves NODE_NAME to the host that is generating the PTP events. For example, compute-1.example.com.
In a cluster with bare-metal events configured, set the http-event-publishers field to hw-event-publisher-service.openshift-bare-metal-events.svc.cluster.local:9043 in the cloud event sidecar deployment CR.

Deploy the consumer-events-subscription-service service alongside the events consumer application. For example:

apiVersion: v1
kind: Service
metadata:
  annotations:
    prometheus.io/scrape: "true"
    service.alpha.openshift.io/serving-cert-secret-name: sidecar-consumer-secret
  name: consumer-events-subscription-service
  namespace: cloud-events
  labels:
    app: consumer-service
spec:
  ports:
    - name: sub-port
      port: 9043
  selector:
    app: consumer
  clusterIP: None
  sessionAffinity: None
  type: ClusterIP

Chapter 13. What huge pages do and how they are consumed by applications

13.1. What huge pages do

Memory is managed in blocks known as pages. On most systems, a page is 4Ki. 1Mi of memory is equal to 256 pages; 1Gi of memory is 256,000 pages, and so on. CPUs have a built-in memory management unit that manages a list of these pages in hardware. The Translation Lookaside Buffer (TLB) is a small hardware cache of virtual-to-physical page mappings. If the virtual address passed in a hardware instruction can be found in the TLB, the mapping can be determined quickly. If not, a TLB miss occurs, and the system falls back to slower, software-based address translation, resulting in performance issues. Since the size of the TLB is fixed, the only way to reduce the chance of a TLB miss is to increase the page size.

A huge page is a memory page that is larger than 4Ki. On x86_64 architectures, there are two common huge page sizes: 2Mi and 1Gi. Sizes vary on other architectures. To use huge pages, code must be written so that applications are aware of them. Transparent Huge Pages (THP) attempt to automate the management of huge pages without application knowledge, but they have limitations. In particular, they are limited to 2Mi page sizes. THP can lead to performance degradation on nodes with high memory utilization or fragmentation due to defragmenting efforts of THP, which can lock memory pages. For this reason, some applications may be designed to (or recommend) usage of pre-allocated huge pages instead of THP.

In OpenShift Container Platform, applications in a pod can allocate and consume pre-allocated huge pages.

13.2. How huge pages are consumed by apps

Nodes must pre-allocate huge pages in order for the node to report its huge page capacity. A node can only pre-allocate huge pages for a single size.

Huge pages can be consumed through container-level resource requirements using the resource name hugepages-<size>, where size is the most compact binary notation using integer values supported on a particular node. For example, if a node supports 2048KiB page sizes, it exposes a schedulable resource hugepages-2Mi. Unlike CPU or memory, huge pages do not support over-commitment.

apiVersion: v1
kind: Pod
metadata:
  generateName: hugepages-volume-
spec:
  containers:
  - securityContext:
      privileged: true
    image: rhel7:latest
    command:
    - sleep
    - inf
    name: example
    volumeMounts:
    - mountPath: /dev/hugepages
      name: hugepage
    resources:
      limits:
        hugepages-2Mi: 100Mi 1
        memory: "1Gi"
        cpu: "1"
  volumes:
  - name: hugepage
    emptyDir:
      medium: HugePages

1: Specify the amount of memory for hugepages as the exact amount to be allocated. Do not specify this value as the amount of memory for hugepages multiplied by the size of the page. For example, given a huge page size of 2MB, if you want to use 100MB of huge-page-backed RAM for your application, then you would allocate 50 huge pages. OpenShift Container Platform handles the math for you. As in the above example, you can specify 100MB directly.

Allocating huge pages of a specific size

Some platforms support multiple huge page sizes. To allocate huge pages of a specific size, precede the huge pages boot command parameters with a huge page size selection parameter hugepagesz=<size>. The <size> value must be specified in bytes with an optional scale suffix [kKmMgG]. The default huge page size can be defined with the default_hugepagesz=<size> boot parameter.

Huge page requirements

Huge page requests must equal the limits. This is the default if limits are specified, but requests are not.
Huge pages are isolated at a pod scope. Container isolation is planned in a future iteration.
EmptyDir volumes backed by huge pages must not consume more huge page memory than the pod request.
Applications that consume huge pages via shmget() with SHM_HUGETLB must run with a supplemental group that matches proc/sys/vm/hugetlb_shm_group.

13.3. Consuming huge pages resources using the Downward API

You can use the Downward API to inject information about the huge pages resources that are consumed by a container.

You can inject the resource allocation as environment variables, a volume plugin, or both. Applications that you develop and run in the container can determine the resources that are available by reading the environment variables or files in the specified volumes.

Procedure

Create a hugepages-volume-pod.yaml file that is similar to the following example:

apiVersion: v1
kind: Pod
metadata:
  generateName: hugepages-volume-
  labels:
    app: hugepages-example
spec:
  containers:
  - securityContext:
      capabilities:
        add: [ "IPC_LOCK" ]
    image: rhel7:latest
    command:
    - sleep
    - inf
    name: example
    volumeMounts:
    - mountPath: /dev/hugepages
      name: hugepage
    - mountPath: /etc/podinfo
      name: podinfo
    resources:
      limits:
        hugepages-1Gi: 2Gi
        memory: "1Gi"
        cpu: "1"
      requests:
        hugepages-1Gi: 2Gi
    env:
    - name: REQUESTS_HUGEPAGES_1GI <.>
      valueFrom:
        resourceFieldRef:
          containerName: example
          resource: requests.hugepages-1Gi
  volumes:
  - name: hugepage
    emptyDir:
      medium: HugePages
  - name: podinfo
    downwardAPI:
      items:
        - path: "hugepages_1G_request" <.>
          resourceFieldRef:
            containerName: example
            resource: requests.hugepages-1Gi
            divisor: 1Gi

<.> Specifies to read the resource use from requests.hugepages-1Gi and expose the value as the REQUESTS_HUGEPAGES_1GI environment variable. <.> Specifies to read the resource use from requests.hugepages-1Gi and expose the value as the file /etc/podinfo/hugepages_1G_request.

Create the pod from the hugepages-volume-pod.yaml file:
```
$ oc create -f hugepages-volume-pod.yaml
```

Verification

Check the value of the REQUESTS_HUGEPAGES_1GI environment variable:

$ oc exec -it $(oc get pods -l app=hugepages-example -o jsonpath='{.items[0].metadata.name}') \
     -- env | grep REQUESTS_HUGEPAGES_1GI

Example output

REQUESTS_HUGEPAGES_1GI=2147483648

Check the value of the /etc/podinfo/hugepages_1G_request file:

$ oc exec -it $(oc get pods -l app=hugepages-example -o jsonpath='{.items[0].metadata.name}') \
     -- cat /etc/podinfo/hugepages_1G_request

Example output

Additional resources

Allowing containers to consume Downward API objects

13.4. Configuring huge pages at boot time

Nodes must pre-allocate huge pages used in an OpenShift Container Platform cluster. There are two ways of reserving huge pages: at boot time and at run time. Reserving at boot time increases the possibility of success because the memory has not yet been significantly fragmented. The Node Tuning Operator currently supports boot time allocation of huge pages on specific nodes.

Procedure

To minimize node reboots, the order of the steps below needs to be followed:

Label all nodes that need the same huge pages setting by a label.

$ oc label node <node_using_hugepages> node-role.kubernetes.io/worker-hp=

Create a file with the following content and name it hugepages-tuned-boottime.yaml:

apiVersion: tuned.openshift.io/v1
kind: Tuned
metadata:
  name: hugepages 1
  namespace: openshift-cluster-node-tuning-operator
spec:
  profile: 2
  - data: |
      [main]
      summary=Boot time configuration for hugepages
      include=openshift-node
      [bootloader]
      cmdline_openshift_node_hugepages=hugepagesz=2M hugepages=50 3
    name: openshift-node-hugepages

  recommend:
  - machineConfigLabels: 4
      machineconfiguration.openshift.io/role: "worker-hp"
    priority: 30
    profile: openshift-node-hugepages

1: Set the name of the Tuned resource to hugepages.
2: Set the profile section to allocate huge pages.
3: Note the order of parameters is important as some platforms support huge pages of various sizes.
4: Enable machine config pool based matching.

Create the Tuned hugepages object

$ oc create -f hugepages-tuned-boottime.yaml

Create a file with the following content and name it hugepages-mcp.yaml:

apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfigPool
metadata:
  name: worker-hp
  labels:
    worker-hp: ""
spec:
  machineConfigSelector:
    matchExpressions:
      - {key: machineconfiguration.openshift.io/role, operator: In, values: [worker,worker-hp]}
  nodeSelector:
    matchLabels:
      node-role.kubernetes.io/worker-hp: ""

Create the machine config pool:
```
$ oc create -f hugepages-mcp.yaml
```

Given enough non-fragmented memory, all the nodes in the worker-hp machine config pool should now have 50 2Mi huge pages allocated.

$ oc get node <node_using_hugepages> -o jsonpath="{.status.allocatable.hugepages-2Mi}"
100Mi

Note

The TuneD bootloader plugin only supports Red Hat Enterprise Linux CoreOS (RHCOS) worker nodes.

13.5. Disabling Transparent Huge Pages

Procedure

Create a file with the following content and name it thp-disable-tuned.yaml:

apiVersion: tuned.openshift.io/v1
kind: Tuned
metadata:
  name: thp-workers-profile
  namespace: openshift-cluster-node-tuning-operator
spec:
  profile:
  - data: |
      [main]
      summary=Custom tuned profile for OpenShift to turn off THP on worker nodes
      include=openshift-node

      [vm]
      transparent_hugepages=never
    name: openshift-thp-never-worker

  recommend:
  - match:
    - label: node-role.kubernetes.io/worker
    priority: 25
    profile: openshift-thp-never-worker

Create the Tuned object:
```
$ oc create -f thp-disable-tuned.yaml
```

Check the list of active profiles:

$ oc get profile -n openshift-cluster-node-tuning-operator

Verification

Log in to one of the nodes and do a regular THP check to verify if the nodes applied the profile successfully:
```
$ cat /sys/kernel/mm/transparent_hugepage/enabled
```
Example output
```
always madvise [never]
```

Chapter 14. Low latency tuning

14.1. Understanding low latency tuning for cluster nodes

Edge computing has a key role in reducing latency and congestion problems and improving application performance for telco and 5G network applications. Maintaining a network architecture with the lowest possible latency is key for meeting the network performance requirements of 5G. Compared to 4G technology, with an average latency of 50 ms, 5G is targeted to reach latency of 1 ms or less. This reduction in latency boosts wireless throughput by a factor of 10.

14.1.1. About low latency

Many of the deployed applications in the Telco space require low latency that can only tolerate zero packet loss. Tuning for zero packet loss helps mitigate the inherent issues that degrade network performance. For more information, see Tuning for Zero Packet Loss in Red Hat OpenStack Platform (RHOSP).

The Edge computing initiative also comes in to play for reducing latency rates. Think of it as being on the edge of the cloud and closer to the user. This greatly reduces the distance between the user and distant data centers, resulting in reduced application response times and performance latency.

Administrators must be able to manage their many Edge sites and local services in a centralized way so that all of the deployments can run at the lowest possible management cost. They also need an easy way to deploy and configure certain nodes of their cluster for real-time low latency and high-performance purposes. Low latency nodes are useful for applications such as Cloud-native Network Functions (CNF) and Data Plane Development Kit (DPDK).

OpenShift Container Platform currently provides mechanisms to tune software on an OpenShift Container Platform cluster for real-time running and low latency (around <20 microseconds reaction time). This includes tuning the kernel and OpenShift Container Platform set values, installing a kernel, and reconfiguring the machine. But this method requires setting up four different Operators and performing many configurations that, when done manually, is complex and could be prone to mistakes.

OpenShift Container Platform uses the Node Tuning Operator to implement automatic tuning to achieve low latency performance for OpenShift Container Platform applications. The cluster administrator uses this performance profile configuration that makes it easier to make these changes in a more reliable way. The administrator can specify whether to update the kernel to kernel-rt, reserve CPUs for cluster and operating system housekeeping duties, including pod infra containers, and isolate CPUs for application containers to run the workloads.

Important

In OpenShift Container Platform 4.14, if you apply a performance profile to your cluster, all nodes in the cluster will reboot. This reboot includes control plane nodes and worker nodes that were not targeted by the performance profile. This is a known issue in OpenShift Container Platform 4.14 because this release uses Linux control group version 2 (cgroup v2) in alignment with RHEL 9. The low latency tuning features associated with the performance profile do not support cgroup v2, therefore the nodes reboot to switch back to the cgroup v1 configuration.

To revert all nodes in the cluster to the cgroups v2 configuration, you must edit the Node resource. (OCPBUGS-16976)

Note

In Telco, clusters using PerformanceProfile for low latency, real-time, and Data Plane Development Kit (DPDK) workloads automatically revert to cgroups v1 due to the lack of cgroups v2 support. Enabling cgroup v2 is not supported if you are using PerformanceProfile.

OpenShift Container Platform also supports workload hints for the Node Tuning Operator that can tune the PerformanceProfile to meet the demands of different industry environments. Workload hints are available for highPowerConsumption (very low latency at the cost of increased power consumption) and realTime (priority given to optimum latency). A combination of true/false settings for these hints can be used to deal with application-specific workload profiles and requirements.

Workload hints simplify the fine-tuning of performance to industry sector settings. Instead of a “one size fits all” approach, workload hints can cater to usage patterns such as placing priority on:

Low latency
Real-time capability
Efficient use of power

Ideally, all of the previously listed items are prioritized. Some of these items come at the expense of others however. The Node Tuning Operator is now aware of the workload expectations and better able to meet the demands of the workload. The cluster admin can now specify into which use case that workload falls. The Node Tuning Operator uses the PerformanceProfile to fine tune the performance settings for the workload.

The environment in which an application is operating influences its behavior. For a typical data center with no strict latency requirements, only minimal default tuning is needed that enables CPU partitioning for some high performance workload pods. For data centers and workloads where latency is a higher priority, measures are still taken to optimize power consumption. The most complicated cases are clusters close to latency-sensitive equipment such as manufacturing machinery and software-defined radios. This last class of deployment is often referred to as Far edge. For Far edge deployments, ultra-low latency is the ultimate priority, and is achieved at the expense of power management.

14.1.2. About Hyper-Threading for low latency and real-time applications

Hyper-Threading is an Intel processor technology that allows a physical CPU processor core to function as two logical cores, executing two independent threads simultaneously. Hyper-Threading allows for better system throughput for certain workload types where parallel processing is beneficial. The default OpenShift Container Platform configuration expects Hyper-Threading to be enabled.

For telecommunications applications, it is important to design your application infrastructure to minimize latency as much as possible. Hyper-Threading can slow performance times and negatively affect throughput for compute-intensive workloads that require low latency. Disabling Hyper-Threading ensures predictable performance and can decrease processing times for these workloads.

Note

Hyper-Threading implementation and configuration differs depending on the hardware you are running OpenShift Container Platform on. Consult the relevant host hardware tuning information for more details of the Hyper-Threading implementation specific to that hardware. Disabling Hyper-Threading can increase the cost per core of the cluster.

Additional resources

Configuring Hyper-Threading for a cluster

14.2. Tuning nodes for low latency with the performance profile

Tune nodes for low latency by using the cluster performance profile. You can restrict CPUs for infra and application containers, configure huge pages, Hyper-Threading, and configure CPU partitions for latency-sensitive processes.

14.2.1. Creating a performance profile

You can create a cluster performance profile by using the Performance Profile Creator (PPC) tool. The PPC is a function of the Node Tuning Operator.

The PPC combines information about your cluster with user-supplied configurations to generate a performance profile that is appropriate to your hardware, topology and use-case.

Note

Performance profiles are applicable only to bare-metal environments where the cluster has direct access to the underlying hardware resources. You can configure performances profiles for both single-node OpenShift and multi-node clusters.

The following is a high-level workflow for creating and applying a performance profile in your cluster:

Create a machine config pool (MCP) for nodes that you want to target with performance configurations. In single-node OpenShift clusters, you must use the master MCP because there is only one node in the cluster.
Gather information about your cluster using the must-gather command.
Use the PPC tool to create a performance profile by using either of the following methods:
- Run the PPC tool by using Podman.
- Run the PPC tool by using a wrapper script.
Configure the performance profile for your use case and apply the performance profile to your cluster.

Note

14.2.1.1. About the Performance Profile Creator

The Performance Profile Creator (PPC) is a command-line tool, delivered with the Node Tuning Operator, that can help you to create a performance profile for your cluster.

Initially, you can use the PPC tool to process the must-gather data to display key performance configurations for your cluster, including the following information:

NUMA cell partitioning with the allocated CPU IDs
Hyper-Threading node configuration

You can use this information to help you configure the performance profile.

Running the PPC

Specify performance configuration arguments to the PPC tool to generate a proposed performance profile that is appropriate for your hardware, topology, and use-case.

You can run the PPC by using one of the following methods:

Run the PPC by using Podman
Run the PPC by using the wrapper script

Note

Using the wrapper script abstracts some of the more granular Podman tasks into an executable script. For example, the wrapper script handles tasks such as pulling and running the required container image, mounting directories into the container, and providing parameters directly to the container through Podman. Both methods achieve the same result.

14.2.1.2. Creating a machine config pool to target nodes for performance tuning

For multi-node clusters, you can define a machine config pool (MCP) to identify the target nodes that you want to configure with a performance profile.

In single-node OpenShift clusters, you must use the master MCP because there is only one node in the cluster. You do not need to create a separate MCP for single-node OpenShift clusters.

Prerequisites

You have cluster-admin role access.
You installed the OpenShift CLI (oc).

Procedure

Label the target nodes for configuration by running the following command:
```
$ oc label node <node_name> node-role.kubernetes.io/worker-cnf="" 1
```
1
Replace <node_name> with the name of your node. This example applies the worker-cnf label.

Create a MachineConfigPool resource containing the target nodes:

Create a YAML file that defines the MachineConfigPool resource:

Example mcp-worker-cnf.yaml file

apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfigPool
metadata:
  name: worker-cnf 1
  labels:
    machineconfiguration.openshift.io/role: worker-cnf 2
spec:
  machineConfigSelector:
    matchExpressions:
      - {
           key: machineconfiguration.openshift.io/role,
           operator: In,
           values: [worker, worker-cnf],
        }
  paused: false
  nodeSelector:
    matchLabels:
      node-role.kubernetes.io/worker-cnf: "" 3

1: Specify a name for the MachineConfigPool resource.
2: Specify a unique label for the machine config pool.
3: Specify the nodes with the target label that you defined.

Apply the MachineConfigPool resource by running the following command:

$ oc apply -f mcp-worker-cnf.yaml

Example output

machineconfigpool.machineconfiguration.openshift.io/worker-cnf created

Verification

Check the machine config pools in your cluster by running the following command:

$ oc get mcp

Example output

NAME         CONFIG                                                 UPDATED   UPDATING   DEGRADED   MACHINECOUNT   READYMACHINECOUNT   UPDATEDMACHINECOUNT   DEGRADEDMACHINECOUNT   AGE
master       rendered-master-58433c7c3c1b4ed5ffef95234d451490       True      False      False      3              3                   3                     0                      6h46m
worker       rendered-worker-168f52b168f151e4f853259729b6azc4       True      False      False      2              2                   2                     0                      6h46m
worker-cnf   rendered-worker-cnf-168f52b168f151e4f853259729b6azc4   True      False      False      1              1                   1                     0                      73s

14.2.1.3. Gathering data about your cluster for the PPC

The Performance Profile Creator (PPC) tool requires must-gather data. As a cluster administrator, run the must-gather command to capture information about your cluster.

Prerequisites

Access to the cluster as a user with the cluster-admin role.
You installed the OpenShift CLI (oc).
You identified a target MCP that you want to configure with a performance profile.

Procedure

Navigate to the directory where you want to store the must-gather data.
Collect cluster information by running the following command:
```
$ oc adm must-gather
```
The command creates a folder with the must-gather data in your local directory with a naming format similar to the following: must-gather.local.1971646453781853027.
Optional: Create a compressed file from the must-gather directory:
```
$ tar cvaf must-gather.tar.gz <must_gather_folder> 1
```
1
Replace with the name of the must-gather data folder.
Note
Compressed output is required if you are running the Performance Profile Creator wrapper script.

Additional resources

For more information about the must-gather tool, see Gathering data about your cluster.

14.2.1.4. Running the Performance Profile Creator using Podman

As a cluster administrator, you can use Podman with the Performance Profile Creator (PPC) to create a performance profile.

For more information about the PPC arguments, see the section "Performance Profile Creator arguments".

Important

The PPC uses the must-gather data from your cluster to create the performance profile. If you make any changes to your cluster, such as relabeling a node targeted for performance configuration, you must re-create the must-gather data before running PPC again.

Prerequisites

Access to the cluster as a user with the cluster-admin role.
A cluster installed on bare-metal hardware.
You installed podman and the OpenShift CLI (oc).
Access to the Node Tuning Operator image.
You identified a machine config pool containing target nodes for configuration.
You have access to the must-gather data for your cluster.

Procedure

Check the machine config pool by running the following command:

$ oc get mcp

Example output

NAME         CONFIG                                                 UPDATED   UPDATING   DEGRADED   MACHINECOUNT   READYMACHINECOUNT   UPDATEDMACHINECOUNT   DEGRADEDMACHINECOUNT   AGE
master       rendered-master-58433c8c3c0b4ed5feef95434d455490       True      False      False      3              3                   3                     0                      8h
worker       rendered-worker-668f56a164f151e4a853229729b6adc4       True      False      False      2              2                   2                     0                      8h
worker-cnf   rendered-worker-cnf-668f56a164f151e4a853229729b6adc4   True      False      False      1              1                   1                     0                      79m

Use Podman to authenticate to registry.redhat.io by running the following command:
```
$ podman login registry.redhat.io
```
```
Username: <user_name>
Password: <password>
```

Optional: Display help for the PPC tool by running the following command:

$ podman run --rm --entrypoint performance-profile-creator registry.redhat.io/openshift4/ose-cluster-node-tuning-rhel9-operator:v4.14 -h

Example output

A tool that automates creation of Performance Profiles

Usage:
  performance-profile-creator [flags]

Flags:
      --disable-ht                        Disable Hyperthreading
  -h, --help                              help for performance-profile-creator
      --info string                       Show cluster information; requires --must-gather-dir-path, ignore the other arguments. [Valid values: log, json] (default "log")
      --mcp-name string                   MCP name corresponding to the target machines (required)
      --must-gather-dir-path string       Must gather directory path (default "must-gather")
      --offlined-cpu-count int            Number of offlined CPUs
      --per-pod-power-management          Enable Per Pod Power Management
      --power-consumption-mode string     The power consumption mode.  [Valid values: default, low-latency, ultra-low-latency] (default "default")
      --profile-name string               Name of the performance profile to be created (default "performance")
      --reserved-cpu-count int            Number of reserved CPUs (required)
      --rt-kernel                         Enable Real Time Kernel (required)
      --split-reserved-cpus-across-numa   Split the Reserved CPUs across NUMA nodes
      --topology-manager-policy string    Kubelet Topology Manager Policy of the performance profile to be created. [Valid values: single-numa-node, best-effort, restricted] (default "restricted")
      --user-level-networking             Run with User level Networking(DPDK) enabled

To display information about the cluster, run the PPC tool with the log argument by running the following command:

$ podman run --entrypoint performance-profile-creator -v <path_to_must_gather>:/must-gather:z registry.redhat.io/openshift4/ose-cluster-node-tuning-rhel9-operator:v4.14 --info log --must-gather-dir-path /must-gather

--entrypoint performance-profile-creator defines the performance profile creator as a new entry point to podman.
-v <path_to_must_gather> specifies the path to either of the following components:
- The directory containing the must-gather data.
- An existing directory containing the must-gather decompressed .tar file.

--info log specifies a value for the output format.

Example output

level=info msg="Cluster info:"
level=info msg="MCP 'master' nodes:"
level=info msg=---
level=info msg="MCP 'worker' nodes:"
level=info msg="Node: host.example.com (NUMA cells: 1, HT: true)"
level=info msg="NUMA cell 0 : [0 1 2 3]"
level=info msg="CPU(s): 4"
level=info msg="Node: host1.example.com (NUMA cells: 1, HT: true)"
level=info msg="NUMA cell 0 : [0 1 2 3]"
level=info msg="CPU(s): 4"
level=info msg=---
level=info msg="MCP 'worker-cnf' nodes:"
level=info msg="Node: host2.example.com (NUMA cells: 1, HT: true)"
level=info msg="NUMA cell 0 : [0 1 2 3]"
level=info msg="CPU(s): 4"
level=info msg=---

Create a performance profile by running the following command. The example uses sample PPC arguments and values:
```
$ podman run --entrypoint performance-profile-creator -v <path_to_must_gather>:/must-gather:z registry.redhat.io/openshift4/ose-cluster-node-tuning-rhel9-operator:v4.14 --mcp-name=worker-cnf --reserved-cpu-count=1 --rt-kernel=true --split-reserved-cpus-across-numa=false --must-gather-dir-path /must-gather --power-consumption-mode=ultra-low-latency --offlined-cpu-count=1 > my-performance-profile.yaml
```
- -v <path_to_must_gather> specifies the path to either of the following components:
  - The directory containing the must-gather data.
  - The directory containing the must-gather decompressed .tar file.
- --mcp-name=worker-cnf specifies the worker-=cnf machine config pool.
- --reserved-cpu-count=1 specifies one reserved CPU.
- --rt-kernel=true enables the real-time kernel.
- --split-reserved-cpus-across-numa=false disables reserved CPUs splitting across NUMA nodes.
- --power-consumption-mode=ultra-low-latency specifies minimal latency at the cost of increased power consumption.
- --offlined-cpu-count=1 specifies one offlined CPU.
  Note
  The mcp-name argument in this example is set to worker-cnf based on the output of the command oc get mcp. For single-node OpenShift use --mcp-name=master.
  Example output
```
level=info msg="Nodes targeted by worker-cnf MCP are: [worker-2]"
level=info msg="NUMA cell(s): 1"
level=info msg="NUMA cell 0 : [0 1 2 3]"
level=info msg="CPU(s): 4"
level=info msg="1 reserved CPUs allocated: 0 "
level=info msg="2 isolated CPUs allocated: 2-3"
level=info msg="Additional Kernel Args based on configuration: []"
```

Review the created YAML file by running the following command:

$ cat my-performance-profile.yaml

Example output

---
apiVersion: performance.openshift.io/v2
kind: PerformanceProfile
metadata:
  name: performance
spec:
  cpu:
    isolated: 2-3
    offlined: "1"
    reserved: "0"
  machineConfigPoolSelector:
    machineconfiguration.openshift.io/role: worker-cnf
  nodeSelector:
    node-role.kubernetes.io/worker-cnf: ""
  numa:
    topologyPolicy: restricted
  realTimeKernel:
    enabled: true
  workloadHints:
    highPowerConsumption: true
    perPodPowerManagement: false
    realTime: true

Apply the generated profile:

$ oc apply -f my-performance-profile.yaml

Example output

performanceprofile.performance.openshift.io/performance created

14.2.1.5. Running the Performance Profile Creator wrapper script

The wrapper script simplifies the process of creating a performance profile with the Performance Profile Creator (PPC) tool. The script handles tasks such as pulling and running the required container image, mounting directories into the container, and providing parameters directly to the container through Podman.

For more information about the Performance Profile Creator arguments, see the section "Performance Profile Creator arguments".

Important

Prerequisites

Access to the cluster as a user with the cluster-admin role.
A cluster installed on bare-metal hardware.
You installed podman and the OpenShift CLI (oc).
Access to the Node Tuning Operator image.
You identified a machine config pool containing target nodes for configuration.
Access to the must-gather tarball.

Procedure

Create a file on your local machine named, for example, run-perf-profile-creator.sh:
```
$ vi run-perf-profile-creator.sh
```

Paste the following code into the file:

#!/bin/bash

readonly CONTAINER_RUNTIME=${CONTAINER_RUNTIME:-podman}
readonly CURRENT_SCRIPT=$(basename "$0")
readonly CMD="${CONTAINER_RUNTIME} run --entrypoint performance-profile-creator"
readonly IMG_EXISTS_CMD="${CONTAINER_RUNTIME} image exists"
readonly IMG_PULL_CMD="${CONTAINER_RUNTIME} image pull"
readonly MUST_GATHER_VOL="/must-gather"

NTO_IMG="registry.redhat.io/openshift4/ose-cluster-node-tuning-rhel9-operator:v4.14"
MG_TARBALL=""
DATA_DIR=""

usage() {
  print "Wrapper usage:"
  print "  ${CURRENT_SCRIPT} [-h] [-p image][-t path] -- [performance-profile-creator flags]"
  print ""
  print "Options:"
  print "   -h                 help for ${CURRENT_SCRIPT}"
  print "   -p                 Node Tuning Operator image"
  print "   -t                 path to a must-gather tarball"

  ${IMG_EXISTS_CMD} "${NTO_IMG}" && ${CMD} "${NTO_IMG}" -h
}

function cleanup {
  [ -d "${DATA_DIR}" ] && rm -rf "${DATA_DIR}"
}
trap cleanup EXIT

exit_error() {
  print "error: $*"
  usage
  exit 1
}

print() {
  echo  "$*" >&2
}

check_requirements() {
  ${IMG_EXISTS_CMD} "${NTO_IMG}" || ${IMG_PULL_CMD} "${NTO_IMG}" || \
      exit_error "Node Tuning Operator image not found"

  [ -n "${MG_TARBALL}" ] || exit_error "Must-gather tarball file path is mandatory"
  [ -f "${MG_TARBALL}" ] || exit_error "Must-gather tarball file not found"

  DATA_DIR=$(mktemp -d -t "${CURRENT_SCRIPT}XXXX") || exit_error "Cannot create the data directory"
  tar -zxf "${MG_TARBALL}" --directory "${DATA_DIR}" || exit_error "Cannot decompress the must-gather tarball"
  chmod a+rx "${DATA_DIR}"

  return 0
}

main() {
  while getopts ':hp:t:' OPT; do
    case "${OPT}" in
      h)
        usage
        exit 0
        ;;
      p)
        NTO_IMG="${OPTARG}"
        ;;
      t)
        MG_TARBALL="${OPTARG}"
        ;;
      ?)
        exit_error "invalid argument: ${OPTARG}"
        ;;
    esac
  done
  shift $((OPTIND - 1))

  check_requirements || exit 1

  ${CMD} -v "${DATA_DIR}:${MUST_GATHER_VOL}:z" "${NTO_IMG}" "$@" --must-gather-dir-path "${MUST_GATHER_VOL}"
  echo "" 1>&2
}

main "$@"

Add execute permissions for everyone on this script:
```
$ chmod a+x run-perf-profile-creator.sh
```
Use Podman to authenticate to registry.redhat.io by running the following command:
```
$ podman login registry.redhat.io
```
```
Username: <user_name>
Password: <password>
```

Optional: Display help for the PPC tool by running the following command:

$ ./run-perf-profile-creator.sh -h

Example output

Wrapper usage:
  run-perf-profile-creator.sh [-h] [-p image][-t path] -- [performance-profile-creator flags]

Options:
   -h                 help for run-perf-profile-creator.sh
   -p                 Node Tuning Operator image
   -t                 path to a must-gather tarball
A tool that automates creation of Performance Profiles

Usage:
  performance-profile-creator [flags]

Flags:
      --disable-ht                        Disable Hyperthreading
  -h, --help                              help for performance-profile-creator
      --info string                       Show cluster information; requires --must-gather-dir-path, ignore the other arguments. [Valid values: log, json] (default "log")
      --mcp-name string                   MCP name corresponding to the target machines (required)
      --must-gather-dir-path string       Must gather directory path (default "must-gather")
      --offlined-cpu-count int            Number of offlined CPUs
      --per-pod-power-management          Enable Per Pod Power Management
      --power-consumption-mode string     The power consumption mode.  [Valid values: default, low-latency, ultra-low-latency] (default "default")
      --profile-name string               Name of the performance profile to be created (default "performance")
      --reserved-cpu-count int            Number of reserved CPUs (required)
      --rt-kernel                         Enable Real Time Kernel (required)
      --split-reserved-cpus-across-numa   Split the Reserved CPUs across NUMA nodes
      --topology-manager-policy string    Kubelet Topology Manager Policy of the performance profile to be created. [Valid values: single-numa-node, best-effort, restricted] (default "restricted")
      --user-level-networking             Run with User level Networking(DPDK) enabled

Note

You can optionally set a path for the Node Tuning Operator image using the -p option. If you do not set a path, the wrapper script uses the default image: registry.redhat.io/openshift4/ose-cluster-node-tuning-rhel9-operator:v4.14.

To display information about the cluster, run the PPC tool with the log argument by running the following command:

$ ./run-perf-profile-creator.sh -t /<path_to_must_gather_dir>/must-gather.tar.gz -- --info=log

-t /<path_to_must_gather_dir>/must-gather.tar.gz specifies the path to directory containing the must-gather tarball. This is a required argument for the wrapper script.

Example output

level=info msg="Cluster info:"
level=info msg="MCP 'master' nodes:"
level=info msg=---
level=info msg="MCP 'worker' nodes:"
level=info msg="Node: host.example.com (NUMA cells: 1, HT: true)"
level=info msg="NUMA cell 0 : [0 1 2 3]"
level=info msg="CPU(s): 4"
level=info msg="Node: host1.example.com (NUMA cells: 1, HT: true)"
level=info msg="NUMA cell 0 : [0 1 2 3]"
level=info msg="CPU(s): 4"
level=info msg=---
level=info msg="MCP 'worker-cnf' nodes:"
level=info msg="Node: host2.example.com (NUMA cells: 1, HT: true)"
level=info msg="NUMA cell 0 : [0 1 2 3]"
level=info msg="CPU(s): 4"
level=info msg=---

Create a performance profile by running the following command.
```
$ ./run-perf-profile-creator.sh -t /path-to-must-gather/must-gather.tar.gz -- --mcp-name=worker-cnf --reserved-cpu-count=1 --rt-kernel=true --split-reserved-cpus-across-numa=false --power-consumption-mode=ultra-low-latency --offlined-cpu-count=1 > my-performance-profile.yaml
```
This example uses sample PPC arguments and values.
- --mcp-name=worker-cnf specifies the worker-=cnf machine config pool.
- --reserved-cpu-count=1 specifies one reserved CPU.
- --rt-kernel=true enables the real-time kernel.
- --split-reserved-cpus-across-numa=false disables reserved CPUs splitting across NUMA nodes.
- --power-consumption-mode=ultra-low-latency specifies minimal latency at the cost of increased power consumption.
- --offlined-cpu-count=1 specifies one offlined CPUs.
  Note
  The mcp-name argument in this example is set to worker-cnf based on the output of the command oc get mcp. For single-node OpenShift use --mcp-name=master.

Review the created YAML file by running the following command:

$ cat my-performance-profile.yaml

Example output

---
apiVersion: performance.openshift.io/v2
kind: PerformanceProfile
metadata:
  name: performance
spec:
  cpu:
    isolated: 2-3
    offlined: "1"
    reserved: "0"
  machineConfigPoolSelector:
    machineconfiguration.openshift.io/role: worker-cnf
  nodeSelector:
    node-role.kubernetes.io/worker-cnf: ""
  numa:
    topologyPolicy: restricted
  realTimeKernel:
    enabled: true
  workloadHints:
    highPowerConsumption: true
    perPodPowerManagement: false
    realTime: true

Apply the generated profile:

$ oc apply -f my-performance-profile.yaml

Example output

performanceprofile.performance.openshift.io/performance created

14.2.1.6. Performance Profile Creator arguments

Table 14.1. Required Performance Profile Creator arguments
Argument	Description
`mcp-name`	Name for MCP; for example, `worker-cnf` corresponding to the target machines.
`must-gather-dir-path`	The path of the must gather directory. This argument is only required if you run the PPC tool by using Podman. If you use the PPC with the wrapper script, do not use this argument. Instead, specify the directory path to the `must-gather` tarball by using the `-t` option for the wrapper script.
`reserved-cpu-count`	Number of reserved CPUs. Use a natural number greater than zero.
`rt-kernel`	Enables real-time kernel. Possible values: `true` or `false`.

Table 14.2. Optional Performance Profile Creator arguments
Argument	Description
`disable-ht`	Disable Hyper-Threading. Possible values: `true` or `false`. Default: `false`. Warning If this argument is set to `true` you should not disable Hyper-Threading in the BIOS. Disabling Hyper-Threading is accomplished with a kernel command line argument.
`info`	This captures cluster information. This argument also requires the `must-gather-dir-path` argument. If any other arguments are set they are ignored. Possible values: `log` `JSON` Default: `log`.
`offlined-cpu-count`	Number of offlined CPUs. Note Use a natural number greater than zero. If not enough logical processors are offlined, then error messages are logged. The messages are: Error: failed to compute the reserved and isolated CPUs: please ensure that reserved-cpu-count plus offlined-cpu-count should be in the range [0,1] Error: failed to compute the reserved and isolated CPUs: please specify the offlined CPU count in the range [0,1]
`power-consumption-mode`	The power consumption mode. Possible values: `default`: Performance achieved through CPU partitioning only. `low-latency`: Enhanced measures to improve latency. `ultra-low-latency`: Priority given to optimal latency, at the expense of power management. Default: `default`.
`per-pod-power-management`	Enable per pod power management. You cannot use this argument if you configured `ultra-low-latency` as the power consumption mode. Possible values: `true` or `false`. Default: `false`.
`profile-name`	Name of the performance profile to create. Default: `performance`.
`split-reserved-cpus-across-numa`	Split the reserved CPUs across NUMA nodes. Possible values: `true` or `false`. Default: `false`.
`topology-manager-policy`	Kubelet Topology Manager policy of the performance profile to be created. Possible values: `single-numa-node` `best-effort` `restricted` Default: `restricted`.
`user-level-networking`	Run with user level networking (DPDK) enabled. Possible values: `true` or `false`. Default: `false`.

14.2.1.7. Reference performance profiles

Use the following reference performance profiles as the basis to develop your own custom profiles.

14.2.1.7.1. Performance profile template for clusters that use OVS-DPDK on OpenStack

To maximize machine performance in a cluster that uses Open vSwitch with the Data Plane Development Kit (OVS-DPDK) on Red Hat OpenStack Platform (RHOSP), you can use a performance profile.

You can use the following performance profile template to create a profile for your deployment.

Performance profile template for clusters that use OVS-DPDK

apiVersion: performance.openshift.io/v2
kind: PerformanceProfile
metadata:
  name: cnf-performanceprofile
spec:
  additionalKernelArgs:
    - nmi_watchdog=0
    - audit=0
    - mce=off
    - processor.max_cstate=1
    - idle=poll
    - intel_idle.max_cstate=0
    - default_hugepagesz=1GB
    - hugepagesz=1G
    - intel_iommu=on
  cpu:
    isolated: <CPU_ISOLATED>
    reserved: <CPU_RESERVED>
  hugepages:
    defaultHugepagesSize: 1G
    pages:
      - count: <HUGEPAGES_COUNT>
        node: 0
        size: 1G
  nodeSelector:
    node-role.kubernetes.io/worker: ''
  realTimeKernel:
    enabled: false
    globallyDisableIrqLoadBalancing: true

Insert values that are appropriate for your configuration for the CPU_ISOLATED, CPU_RESERVED, and HUGEPAGES_COUNT keys.

14.2.1.7.2. Telco RAN DU reference design performance profile

The following performance profile configures node-level performance settings for OpenShift Container Platform clusters on commodity hardware to host telco RAN DU workloads.

Telco RAN DU reference design performance profile

apiVersion: performance.openshift.io/v2
kind: PerformanceProfile
metadata:
  # if you change this name make sure the 'include' line in TunedPerformancePatch.yaml
  # matches this name: include=openshift-node-performance-${PerformanceProfile.metadata.name}
  # Also in file 'validatorCRs/informDuValidator.yaml':
  # name: 50-performance-${PerformanceProfile.metadata.name}
  name: openshift-node-performance-profile
  annotations:
    ran.openshift.io/reference-configuration: "ran-du.redhat.com"
spec:
  additionalKernelArgs:
    - "rcupdate.rcu_normal_after_boot=0"
    - "efi=runtime"
    - "vfio_pci.enable_sriov=1"
    - "vfio_pci.disable_idle_d3=1"
    - "module_blacklist=irdma"
  cpu:
    isolated: $isolated
    reserved: $reserved
  hugepages:
    defaultHugepagesSize: $defaultHugepagesSize
    pages:
      - size: $size
        count: $count
        node: $node
  machineConfigPoolSelector:
    pools.operator.machineconfiguration.openshift.io/$mcp: ""
  nodeSelector:
    node-role.kubernetes.io/$mcp: ""
  numa:
    topologyPolicy: "restricted"
  # To use the standard (non-realtime) kernel, set enabled to false
  realTimeKernel:
    enabled: true
  workloadHints:
    # WorkloadHints defines the set of upper level flags for different type of workloads.
    # See https://github.com/openshift/cluster-node-tuning-operator/blob/master/docs/performanceprofile/performance_profile.md#workloadhints
    # for detailed descriptions of each item.
    # The configuration below is set for a low latency, performance mode.
    realTime: true
    highPowerConsumption: false
    perPodPowerManagement: false

14.2.1.7.3. Telco core reference design performance profile

The following performance profile configures node-level performance settings for OpenShift Container Platform clusters on commodity hardware to host telco core workloads.

Telco core reference design performance profile

apiVersion: performance.openshift.io/v2
kind: PerformanceProfile
metadata:
  # if you change this name make sure the 'include' line in TunedPerformancePatch.yaml
  # matches this name: include=openshift-node-performance-${PerformanceProfile.metadata.name}
  # Also in file 'validatorCRs/informDuValidator.yaml':
  # name: 50-performance-${PerformanceProfile.metadata.name}
  name: openshift-node-performance-profile
  annotations:
    ran.openshift.io/reference-configuration: "ran-du.redhat.com"
spec:
  additionalKernelArgs:
    - "rcupdate.rcu_normal_after_boot=0"
    - "efi=runtime"
    - "vfio_pci.enable_sriov=1"
    - "vfio_pci.disable_idle_d3=1"
    - "module_blacklist=irdma"
  cpu:
    isolated: $isolated
    reserved: $reserved
  hugepages:
    defaultHugepagesSize: $defaultHugepagesSize
    pages:
      - size: $size
        count: $count
        node: $node
  machineConfigPoolSelector:
    pools.operator.machineconfiguration.openshift.io/$mcp: ""
  nodeSelector:
    node-role.kubernetes.io/$mcp: ""
  numa:
    topologyPolicy: "restricted"
  # To use the standard (non-realtime) kernel, set enabled to false
  realTimeKernel:
    enabled: true
  workloadHints:
    # WorkloadHints defines the set of upper level flags for different type of workloads.
    # See https://github.com/openshift/cluster-node-tuning-operator/blob/master/docs/performanceprofile/performance_profile.md#workloadhints
    # for detailed descriptions of each item.
    # The configuration below is set for a low latency, performance mode.
    realTime: true
    highPowerConsumption: false
    perPodPowerManagement: false

14.2.2. Supported performance profile API versions

The Node Tuning Operator supports v2, v1, and v1alpha1 for the performance profile apiVersion field. The v1 and v1alpha1 APIs are identical. The v2 API includes an optional boolean field globallyDisableIrqLoadBalancing with a default value of false.

Upgrading the performance profile to use device interrupt processing

When you upgrade the Node Tuning Operator performance profile custom resource definition (CRD) from v1 or v1alpha1 to v2, globallyDisableIrqLoadBalancing is set to true on existing profiles.

Note

globallyDisableIrqLoadBalancing toggles whether IRQ load balancing will be disabled for the Isolated CPU set. When the option is set to true it disables IRQ load balancing for the Isolated CPU set. Setting the option to false allows the IRQs to be balanced across all CPUs.

Upgrading Node Tuning Operator API from v1alpha1 to v1

When upgrading Node Tuning Operator API version from v1alpha1 to v1, the v1alpha1 performance profiles are converted on-the-fly using a "None" Conversion strategy and served to the Node Tuning Operator with API version v1.

Upgrading Node Tuning Operator API from v1alpha1 or v1 to v2

When upgrading from an older Node Tuning Operator API version, the existing v1 and v1alpha1 performance profiles are converted using a conversion webhook that injects the globallyDisableIrqLoadBalancing field with a value of true.

14.2.3. Configuring node power consumption and realtime processing with workload hints

Procedure

Create a PerformanceProfile appropriate for the environment’s hardware and topology by using the Performance Profile Creator (PPC) tool. The following table describes the possible values set for the power-consumption-mode flag associated with the PPC tool and the workload hint that is applied.

Table 14.3. Impact of combinations of power consumption and real-time settings on latency
Performance Profile creator setting	Hint	Environment	Description
Default	workloadHints: highPowerConsumption: false realTime: false	High throughput cluster without latency requirements	Performance achieved through CPU partitioning only.
Low-latency	workloadHints: highPowerConsumption: false realTime: true	Regional data-centers	Both energy savings and low-latency are desirable: compromise between power management, latency and throughput.
Ultra-low-latency	workloadHints: highPowerConsumption: true realTime: true	Far edge clusters, latency critical workloads	Optimized for absolute minimal latency and maximum determinism at the cost of increased power consumption.
Per-pod power management	workloadHints: realTime: true highPowerConsumption: false perPodPowerManagement: true	Critical and non-critical workloads	Allows for power management per pod.

Example

The following configuration is commonly used in a telco RAN DU deployment.

    apiVersion: performance.openshift.io/v2
    kind: PerformanceProfile
    metadata:
      name: workload-hints
    spec:
      ...
      workloadHints:
        realTime: true
        highPowerConsumption: false
        perPodPowerManagement: false 1

1: Disables some debugging and monitoring features that can affect system latency.

Note

When the realTime workload hint flag is set to true in a performance profile, add the cpu-quota.crio.io: disable annotation to every guaranteed pod with pinned CPUs. This annotation is necessary to prevent the degradation of the process performance within the pod. If the realTime workload hint is not explicitly set, it defaults to true.

For more information how combinations of power consumption and real-time settings impact latency, see Understanding workload hints.

14.2.4. Configuring power saving for nodes that run colocated high and low priority workloads

You can enable power savings for a node that has low priority workloads that are colocated with high priority workloads without impacting the latency or throughput of the high priority workloads. Power saving is possible without modifications to the workloads themselves.

Important

The feature is supported on Intel Ice Lake and later generations of Intel CPUs. The capabilities of the processor might impact the latency and throughput of the high priority workloads.

Prerequisites

You enabled C-states and operating system controlled P-states in the BIOS

Procedure

Generate a PerformanceProfile with the per-pod-power-management argument set to true:

$ podman run --entrypoint performance-profile-creator -v \
/must-gather:/must-gather:z registry.redhat.io/openshift4/ose-cluster-node-tuning-operator:v4.14 \
--mcp-name=worker-cnf --reserved-cpu-count=20 --rt-kernel=true \
--split-reserved-cpus-across-numa=false --topology-manager-policy=single-numa-node \
--must-gather-dir-path /must-gather --power-consumption-mode=low-latency \ 1
--per-pod-power-management=true > my-performance-profile.yaml

1: The power-consumption-mode argument must be default or low-latency when the per-pod-power-management argument is set to true.

Example PerformanceProfile with perPodPowerManagement

apiVersion: performance.openshift.io/v2
kind: PerformanceProfile
metadata:
     name: performance
spec:
    [.....]
    workloadHints:
        realTime: true
        highPowerConsumption: false
        perPodPowerManagement: true

Set the default cpufreq governor as an additional kernel argument in the PerformanceProfile custom resource (CR):
```
apiVersion: performance.openshift.io/v2
kind: PerformanceProfile
metadata:
     name: performance
spec:
    ...
    additionalKernelArgs:
    - cpufreq.default_governor=schedutil 1
```
1
Using the schedutil governor is recommended, however, you can use other governors such as the ondemand or powersave governors.
Set the maximum CPU frequency in the TunedPerformancePatch CR:
```
spec:
  profile:
  - data: |
      [sysfs]
      /sys/devices/system/cpu/intel_pstate/max_perf_pct = <x> 1
```
1
The max_perf_pct controls the maximum frequency that the cpufreq driver is allowed to set as a percentage of the maximum supported cpu frequency. This value applies to all CPUs. You can check the maximum supported frequency in /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq. As a starting point, you can use a percentage that caps all CPUs at the All Cores Turbo frequency. The All Cores Turbo frequency is the frequency that all cores will run at when the cores are all fully occupied.

Additional resources

About the Performance Profile Creator
Disabling power saving mode for high priority pods
Managing device interrupt processing for guaranteed pod isolated CPUs

14.2.5. Restricting CPUs for infra and application containers

Generic housekeeping and workload tasks use CPUs in a way that may impact latency-sensitive processes. By default, the container runtime uses all online CPUs to run all containers together, which can result in context switches and spikes in latency. Partitioning the CPUs prevents noisy processes from interfering with latency-sensitive processes by separating them from each other. The following table describes how processes run on a CPU after you have tuned the node using the Node Tuning Operator:

Table 14.4. Process' CPU assignments
Process type	Details
`Burstable` and `BestEffort` pods	Runs on any CPU except where low latency workload is running
Infrastructure pods	Runs on any CPU except where low latency workload is running
Interrupts	Redirects to reserved CPUs (optional in OpenShift Container Platform 4.7 and later)
Kernel processes	Pins to reserved CPUs
Latency-sensitive workload pods	Pins to a specific set of exclusive CPUs from the isolated pool
OS processes/systemd services	Pins to reserved CPUs

The allocatable capacity of cores on a node for pods of all QoS process types, Burstable, BestEffort, or Guaranteed, is equal to the capacity of the isolated pool. The capacity of the reserved pool is removed from the node’s total core capacity for use by the cluster and operating system housekeeping duties.

Example 1

A node features a capacity of 100 cores. Using a performance profile, the cluster administrator allocates 50 cores to the isolated pool and 50 cores to the reserved pool. The cluster administrator assigns 25 cores to QoS Guaranteed pods and 25 cores for BestEffort or Burstable pods. This matches the capacity of the isolated pool.

Example 2

A node features a capacity of 100 cores. Using a performance profile, the cluster administrator allocates 50 cores to the isolated pool and 50 cores to the reserved pool. The cluster administrator assigns 50 cores to QoS Guaranteed pods and one core for BestEffort or Burstable pods. This exceeds the capacity of the isolated pool by one core. Pod scheduling fails because of insufficient CPU capacity.

The exact partitioning pattern to use depends on many factors like hardware, workload characteristics and the expected system load. Some sample use cases are as follows:

If the latency-sensitive workload uses specific hardware, such as a network interface controller (NIC), ensure that the CPUs in the isolated pool are as close as possible to this hardware. At a minimum, you should place the workload in the same Non-Uniform Memory Access (NUMA) node.
The reserved pool is used for handling all interrupts. When depending on system networking, allocate a sufficiently-sized reserve pool to handle all the incoming packet interrupts. In 4.14 and later versions, workloads can optionally be labeled as sensitive.

The decision regarding which specific CPUs should be used for reserved and isolated partitions requires detailed analysis and measurements. Factors like NUMA affinity of devices and memory play a role. The selection also depends on the workload architecture and the specific use case.

Important

The reserved and isolated CPU pools must not overlap and together must span all available cores in the worker node.

To ensure that housekeeping tasks and workloads do not interfere with each other, specify two groups of CPUs in the spec section of the performance profile.

isolated - Specifies the CPUs for the application container workloads. These CPUs have the lowest latency. Processes in this group have no interruptions and can, for example, reach much higher DPDK zero packet loss bandwidth.
reserved - Specifies the CPUs for the cluster and operating system housekeeping duties. Threads in the reserved group are often busy. Do not run latency-sensitive applications in the reserved group. Latency-sensitive applications run in the isolated group.

Procedure

Create a performance profile appropriate for the environment’s hardware and topology.
Add the reserved and isolated parameters with the CPUs you want reserved and isolated for the infra and application containers:
```
apiVersion: performance.openshift.io/v2
kind: PerformanceProfile
metadata:
  name: infra-cpus
spec:
  cpu:
    reserved: "0-4,9" 1
    isolated: "5-8" 2
  nodeSelector: 3
    node-role.kubernetes.io/worker: ""
```
1
Specify which CPUs are for infra containers to perform cluster and operating system housekeeping duties.
2
Specify which CPUs are for application containers to run workloads.
3
Optional: Specify a node selector to apply the performance profile to specific nodes.

14.2.6. Configuring Hyper-Threading for a cluster

To configure Hyper-Threading for an OpenShift Container Platform cluster, set the CPU threads in the performance profile to the same cores that are configured for the reserved or isolated CPU pools.

Note

If you configure a performance profile, and subsequently change the Hyper-Threading configuration for the host, ensure that you update the CPU isolated and reserved fields in the PerformanceProfile YAML to match the new configuration.

Warning

Disabling a previously enabled host Hyper-Threading configuration can cause the CPU core IDs listed in the PerformanceProfile YAML to be incorrect. This incorrect configuration can cause the node to become unavailable because the listed CPUs can no longer be found.

Prerequisites

Access to the cluster as a user with the cluster-admin role.
Install the OpenShift CLI (oc).

Procedure

Ascertain which threads are running on what CPUs for the host you want to configure.

You can view which threads are running on the host CPUs by logging in to the cluster and running the following command:

$ lscpu --all --extended

Example output

CPU NODE SOCKET CORE L1d:L1i:L2:L3 ONLINE MAXMHZ    MINMHZ
0   0    0      0    0:0:0:0       yes    4800.0000 400.0000
1   0    0      1    1:1:1:0       yes    4800.0000 400.0000
2   0    0      2    2:2:2:0       yes    4800.0000 400.0000
3   0    0      3    3:3:3:0       yes    4800.0000 400.0000
4   0    0      0    0:0:0:0       yes    4800.0000 400.0000
5   0    0      1    1:1:1:0       yes    4800.0000 400.0000
6   0    0      2    2:2:2:0       yes    4800.0000 400.0000
7   0    0      3    3:3:3:0       yes    4800.0000 400.0000

In this example, there are eight logical CPU cores running on four physical CPU cores. CPU0 and CPU4 are running on physical Core0, CPU1 and CPU5 are running on physical Core 1, and so on.

Alternatively, to view the threads that are set for a particular physical CPU core (cpu0 in the example below), open a shell prompt and run the following:

$ cat /sys/devices/system/cpu/cpu0/topology/thread_siblings_list

Example output

0-4

Apply the isolated and reserved CPUs in the PerformanceProfile YAML. For example, you can set logical cores CPU0 and CPU4 as isolated, and logical cores CPU1 to CPU3 and CPU5 to CPU7 as reserved. When you configure reserved and isolated CPUs, the infra containers in pods use the reserved CPUs and the application containers use the isolated CPUs.
```
...
  cpu:
    isolated: 0,4
    reserved: 1-3,5-7
...
```
Note
The reserved and isolated CPU pools must not overlap and together must span all available cores in the worker node.

Important

Hyper-Threading is enabled by default on most Intel processors. If you enable Hyper-Threading, all threads processed by a particular core must be isolated or processed on the same core.

When Hyper-Threading is enabled, all guaranteed pods must use multiples of the simultaneous multi-threading (SMT) level to avoid a "noisy neighbor" situation that can cause the pod to fail. See Static policy options for more information.

14.2.6.1. Disabling Hyper-Threading for low latency applications

When configuring clusters for low latency processing, consider whether you want to disable Hyper-Threading before you deploy the cluster. To disable Hyper-Threading, perform the following steps:

Create a performance profile that is appropriate for your hardware and topology.

Set nosmt as an additional kernel argument. The following example performance profile illustrates this setting:

apiVersion: performance.openshift.io/v2
kind: PerformanceProfile
metadata:
  name: example-performanceprofile
spec:
  additionalKernelArgs:
    - nmi_watchdog=0
    - audit=0
    - mce=off
    - processor.max_cstate=1
    - idle=poll
    - intel_idle.max_cstate=0
    - nosmt
  cpu:
    isolated: 2-3
    reserved: 0-1
  hugepages:
    defaultHugepagesSize: 1G
    pages:
      - count: 2
        node: 0
        size: 1G
  nodeSelector:
    node-role.kubernetes.io/performance: ''
  realTimeKernel:
    enabled: true

Note

When you configure reserved and isolated CPUs, the infra containers in pods use the reserved CPUs and the application containers use the isolated CPUs.

14.2.7. Managing device interrupt processing for guaranteed pod isolated CPUs

The Node Tuning Operator can manage host CPUs by dividing them into reserved CPUs for cluster and operating system housekeeping duties, including pod infra containers, and isolated CPUs for application containers to run the workloads. This allows you to set CPUs for low latency workloads as isolated.

Device interrupts are load balanced between all isolated and reserved CPUs to avoid CPUs being overloaded, with the exception of CPUs where there is a guaranteed pod running. Guaranteed pod CPUs are prevented from processing device interrupts when the relevant annotations are set for the pod.

In the performance profile, globallyDisableIrqLoadBalancing is used to manage whether device interrupts are processed or not. For certain workloads, the reserved CPUs are not always sufficient for dealing with device interrupts, and for this reason, device interrupts are not globally disabled on the isolated CPUs. By default, Node Tuning Operator does not disable device interrupts on isolated CPUs.

14.2.7.1. Finding the effective IRQ affinity setting for a node

Some IRQ controllers lack support for IRQ affinity setting and will always expose all online CPUs as the IRQ mask. These IRQ controllers effectively run on CPU 0.

The following are examples of drivers and hardware that Red Hat are aware lack support for IRQ affinity setting. The list is, by no means, exhaustive:

Some RAID controller drivers, such as megaraid_sas
Many non-volatile memory express (NVMe) drivers
Some LAN on motherboard (LOM) network controllers
The driver uses managed_irqs

Note

The reason they do not support IRQ affinity setting might be associated with factors such as the type of processor, the IRQ controller, or the circuitry connections in the motherboard.

If the effective affinity of any IRQ is set to an isolated CPU, it might be a sign of some hardware or driver not supporting IRQ affinity setting. To find the effective affinity, log in to the host and run the following command:

$ find /proc/irq -name effective_affinity -printf "%p: " -exec cat {} \;

Example output

/proc/irq/0/effective_affinity: 1
/proc/irq/1/effective_affinity: 8
/proc/irq/2/effective_affinity: 0
/proc/irq/3/effective_affinity: 1
/proc/irq/4/effective_affinity: 2
/proc/irq/5/effective_affinity: 1
/proc/irq/6/effective_affinity: 1
/proc/irq/7/effective_affinity: 1
/proc/irq/8/effective_affinity: 1
/proc/irq/9/effective_affinity: 2
/proc/irq/10/effective_affinity: 1
/proc/irq/11/effective_affinity: 1
/proc/irq/12/effective_affinity: 4
/proc/irq/13/effective_affinity: 1
/proc/irq/14/effective_affinity: 1
/proc/irq/15/effective_affinity: 1
/proc/irq/24/effective_affinity: 2
/proc/irq/25/effective_affinity: 4
/proc/irq/26/effective_affinity: 2
/proc/irq/27/effective_affinity: 1
/proc/irq/28/effective_affinity: 8
/proc/irq/29/effective_affinity: 4
/proc/irq/30/effective_affinity: 4
/proc/irq/31/effective_affinity: 8
/proc/irq/32/effective_affinity: 8
/proc/irq/33/effective_affinity: 1
/proc/irq/34/effective_affinity: 2

Some drivers use managed_irqs, whose affinity is managed internally by the kernel and userspace cannot change the affinity. In some cases, these IRQs might be assigned to isolated CPUs. For more information about managed_irqs, see Affinity of managed interrupts cannot be changed even if they target isolated CPU.

14.2.7.2. Configuring a node for IRQ dynamic load balancing

Configure a cluster node for IRQ dynamic load balancing to control which cores can receive device interrupt requests (IRQ).

Prerequisites

For core isolation, all server hardware components must support IRQ affinity. To check if the hardware components of your server support IRQ affinity, view the server’s hardware specifications or contact your hardware provider.

Procedure

Log in to the OpenShift Container Platform cluster as a user with cluster-admin privileges.
Set the performance profile apiVersion to use performance.openshift.io/v2.
Remove the globallyDisableIrqLoadBalancing field or set it to false.
Set the appropriate isolated and reserved CPUs. The following snippet illustrates a profile that reserves 2 CPUs. IRQ load-balancing is enabled for pods running on the isolated CPU set:
```
apiVersion: performance.openshift.io/v2
kind: PerformanceProfile
metadata:
  name: dynamic-irq-profile
spec:
  cpu:
    isolated: 2-5
    reserved: 0-1
...
```
Note
When you configure reserved and isolated CPUs, the infra containers in pods use the reserved CPUs and the application containers use the isolated CPUs.

Create the pod that uses exclusive CPUs, and set irq-load-balancing.crio.io and cpu-quota.crio.io annotations to disable. For example:

apiVersion: v1
kind: Pod
metadata:
  name: dynamic-irq-pod
  annotations:
     irq-load-balancing.crio.io: "disable"
     cpu-quota.crio.io: "disable"
spec:
  containers:
  - name: dynamic-irq-pod
    image: "registry.redhat.io/openshift4/cnf-tests-rhel8:v4.14"
    command: ["sleep", "10h"]
    resources:
      requests:
        cpu: 2
        memory: "200M"
      limits:
        cpu: 2
        memory: "200M"
  nodeSelector:
    node-role.kubernetes.io/worker-cnf: ""
  runtimeClassName: performance-dynamic-irq-profile
...

Enter the pod runtimeClassName in the form performance-<profile_name>, where <profile_name> is the name from the PerformanceProfile YAML, in this example, performance-dynamic-irq-profile.
Set the node selector to target a cnf-worker.

Ensure the pod is running correctly. Status should be running, and the correct cnf-worker node should be set:

$ oc get pod -o wide

Expected output

NAME              READY   STATUS    RESTARTS   AGE     IP             NODE          NOMINATED NODE   READINESS GATES
dynamic-irq-pod   1/1     Running   0          5h33m   <ip-address>   <node-name>   <none>           <none>

Get the CPUs that the pod configured for IRQ dynamic load balancing runs on:

$ oc exec -it dynamic-irq-pod -- /bin/bash -c "grep Cpus_allowed_list /proc/self/status | awk '{print $2}'"

Expected output

Cpus_allowed_list:  2-3

Ensure the node configuration is applied correctly. Log in to the node to verify the configuration.

$ oc debug node/<node-name>

Expected output

Starting pod/<node-name>-debug ...
To use host binaries, run `chroot /host`

Pod IP: <ip-address>
If you don't see a command prompt, try pressing enter.

sh-4.4#

Verify that you can use the node file system:
```
sh-4.4# chroot /host
```
Expected output
```
sh-4.4#
```
Ensure the default system CPU affinity mask does not include the dynamic-irq-pod CPUs, for example, CPUs 2 and 3.
```
$ cat /proc/irq/default_smp_affinity
```
Example output
```
33
```

Ensure the system IRQs are not configured to run on the dynamic-irq-pod CPUs:

find /proc/irq/ -name smp_affinity_list -exec sh -c 'i="$1"; mask=$(cat $i); file=$(echo $i); echo $file: $mask' _ {} \;

Example output

/proc/irq/0/smp_affinity_list: 0-5
/proc/irq/1/smp_affinity_list: 5
/proc/irq/2/smp_affinity_list: 0-5
/proc/irq/3/smp_affinity_list: 0-5
/proc/irq/4/smp_affinity_list: 0
/proc/irq/5/smp_affinity_list: 0-5
/proc/irq/6/smp_affinity_list: 0-5
/proc/irq/7/smp_affinity_list: 0-5
/proc/irq/8/smp_affinity_list: 4
/proc/irq/9/smp_affinity_list: 4
/proc/irq/10/smp_affinity_list: 0-5
/proc/irq/11/smp_affinity_list: 0
/proc/irq/12/smp_affinity_list: 1
/proc/irq/13/smp_affinity_list: 0-5
/proc/irq/14/smp_affinity_list: 1
/proc/irq/15/smp_affinity_list: 0
/proc/irq/24/smp_affinity_list: 1
/proc/irq/25/smp_affinity_list: 1
/proc/irq/26/smp_affinity_list: 1
/proc/irq/27/smp_affinity_list: 5
/proc/irq/28/smp_affinity_list: 1
/proc/irq/29/smp_affinity_list: 0
/proc/irq/30/smp_affinity_list: 0-5

14.2.8. Configuring huge pages

Nodes must pre-allocate huge pages used in an OpenShift Container Platform cluster. Use the Node Tuning Operator to allocate huge pages on a specific node.

OpenShift Container Platform provides a method for creating and allocating huge pages. Node Tuning Operator provides an easier method for doing this using the performance profile.

For example, in the hugepages pages section of the performance profile, you can specify multiple blocks of size, count, and, optionally, node:

hugepages:
   defaultHugepagesSize: "1G"
   pages:
   - size:  "1G"
     count:  4
     node:  0 1

1: node is the NUMA node in which the huge pages are allocated. If you omit node, the pages are evenly spread across all NUMA nodes.

Note

Wait for the relevant machine config pool status that indicates the update is finished.

These are the only configuration steps you need to do to allocate huge pages.

Verification

To verify the configuration, see the /proc/meminfo file on the node:

$ oc debug node/ip-10-0-141-105.ec2.internal

# grep -i huge /proc/meminfo

Example output

AnonHugePages:    ###### ##
ShmemHugePages:        0 kB
HugePages_Total:       2
HugePages_Free:        2
HugePages_Rsvd:        0
HugePages_Surp:        0
Hugepagesize:       #### ##
Hugetlb:            #### ##

Use oc describe to report the new size:

$ oc describe node worker-0.ocp4poc.example.com | grep -i huge

Example output

                                   hugepages-1g=true
 hugepages-###:  ###
 hugepages-###:  ###

14.2.8.1. Allocating multiple huge page sizes

You can request huge pages with different sizes under the same container. This allows you to define more complicated pods consisting of containers with different huge page size needs.

For example, you can define sizes 1G and 2M and the Node Tuning Operator will configure both sizes on the node, as shown here:

spec:
  hugepages:
    defaultHugepagesSize: 1G
    pages:
    - count: 1024
      node: 0
      size: 2M
    - count: 4
      node: 1
      size: 1G

14.2.9. Reducing NIC queues using the Node Tuning Operator

The Node Tuning Operator facilitates reducing NIC queues for enhanced performance. Adjustments are made using the performance profile, allowing customization of queues for different network devices.

14.2.9.1. Adjusting the NIC queues with the performance profile

The performance profile lets you adjust the queue count for each network device.

Supported network devices:

Non-virtual network devices
Network devices that support multiple queues (channels)

Unsupported network devices:

Pure software network interfaces
Block devices
Intel DPDK virtual functions

Prerequisites

Access to the cluster as a user with the cluster-admin role.
Install the OpenShift CLI (oc).

Procedure

Log in to the OpenShift Container Platform cluster running the Node Tuning Operator as a user with cluster-admin privileges.
Create and apply a performance profile appropriate for your hardware and topology. For guidance on creating a profile, see the "Creating a performance profile" section.
Edit this created performance profile:
```
$ oc edit -f <your_profile_name>.yaml
```
Populate the spec field with the net object. The object list can contain two fields:
- userLevelNetworking is a required field specified as a boolean flag. If userLevelNetworking is true, the queue count is set to the reserved CPU count for all supported devices. The default is false.
- devices is an optional field specifying a list of devices that will have the queues set to the reserved CPU count. If the device list is empty, the configuration applies to all network devices. The configuration is as follows:
  - interfaceName: This field specifies the interface name, and it supports shell-style wildcards, which can be positive or negative.
    Example wildcard syntax is as follows: <string> .*
    Negative rules are prefixed with an exclamation mark. To apply the net queue changes to all devices other than the excluded list, use !<device>, for example, !eno1.
  - vendorID: The network device vendor ID represented as a 16-bit hexadecimal number with a 0x prefix.
  - deviceID: The network device ID (model) represented as a 16-bit hexadecimal number with a 0x prefix.
    Note
    When a deviceID is specified, the vendorID must also be defined. A device that matches all of the device identifiers specified in a device entry interfaceName, vendorID, or a pair of vendorID plus deviceID qualifies as a network device. This network device then has its net queues count set to the reserved CPU count.
    When two or more devices are specified, the net queues count is set to any net device that matches one of them.

Set the queue count to the reserved CPU count for all devices by using this example performance profile:

apiVersion: performance.openshift.io/v2
kind: PerformanceProfile
metadata:
  name: manual
spec:
  cpu:
    isolated: 3-51,55-103
    reserved: 0-2,52-54
  net:
    userLevelNetworking: true
  nodeSelector:
    node-role.kubernetes.io/worker-cnf: ""

Set the queue count to the reserved CPU count for all devices matching any of the defined device identifiers by using this example performance profile:

apiVersion: performance.openshift.io/v2
kind: PerformanceProfile
metadata:
  name: manual
spec:
  cpu:
    isolated: 3-51,55-103
    reserved: 0-2,52-54
  net:
    userLevelNetworking: true
    devices:
    - interfaceName: "eth0"
    - interfaceName: "eth1"
    - vendorID: "0x1af4"
      deviceID: "0x1000"
  nodeSelector:
    node-role.kubernetes.io/worker-cnf: ""

Set the queue count to the reserved CPU count for all devices starting with the interface name eth by using this example performance profile:

apiVersion: performance.openshift.io/v2
kind: PerformanceProfile
metadata:
  name: manual
spec:
  cpu:
    isolated: 3-51,55-103
    reserved: 0-2,52-54
  net:
    userLevelNetworking: true
    devices:
    - interfaceName: "eth*"
  nodeSelector:
    node-role.kubernetes.io/worker-cnf: ""

Set the queue count to the reserved CPU count for all devices with an interface named anything other than eno1 by using this example performance profile:

apiVersion: performance.openshift.io/v2
kind: PerformanceProfile
metadata:
  name: manual
spec:
  cpu:
    isolated: 3-51,55-103
    reserved: 0-2,52-54
  net:
    userLevelNetworking: true
    devices:
    - interfaceName: "!eno1"
  nodeSelector:
    node-role.kubernetes.io/worker-cnf: ""

Set the queue count to the reserved CPU count for all devices that have an interface name eth0, vendorID of 0x1af4, and deviceID of 0x1000 by using this example performance profile:

apiVersion: performance.openshift.io/v2
kind: PerformanceProfile
metadata:
  name: manual
spec:
  cpu:
    isolated: 3-51,55-103
    reserved: 0-2,52-54
  net:
    userLevelNetworking: true
    devices:
    - interfaceName: "eth0"
    - vendorID: "0x1af4"
      deviceID: "0x1000"
  nodeSelector:
    node-role.kubernetes.io/worker-cnf: ""

Apply the updated performance profile:
```
$ oc apply -f <your_profile_name>.yaml
```

Additional resources

Creating a performance profile.

14.2.9.2. Verifying the queue status

In this section, a number of examples illustrate different performance profiles and how to verify the changes are applied.

Example 1

In this example, the net queue count is set to the reserved CPU count (2) for all supported devices.

The relevant section from the performance profile is:

apiVersion: performance.openshift.io/v2
metadata:
  name: performance
spec:
  kind: PerformanceProfile
  spec:
    cpu:
      reserved: 0-1  #total = 2
      isolated: 2-8
    net:
      userLevelNetworking: true
# ...

Display the status of the queues associated with a device using the following command:
Note
Run this command on the node where the performance profile was applied.
```
$ ethtool -l <device>
```

Verify the queue status before the profile is applied:

$ ethtool -l ens4

Example output

Channel parameters for ens4:
Pre-set maximums:
RX:         0
TX:         0
Other:      0
Combined:   4
Current hardware settings:
RX:         0
TX:         0
Other:      0
Combined:   4

Verify the queue status after the profile is applied:

$ ethtool -l ens4

Example output

Channel parameters for ens4:
Pre-set maximums:
RX:         0
TX:         0
Other:      0
Combined:   4
Current hardware settings:
RX:         0
TX:         0
Other:      0
Combined:   2 1

1: The combined channel shows that the total count of reserved CPUs for all supported devices is 2. This matches what is configured in the performance profile.

Example 2

In this example, the net queue count is set to the reserved CPU count (2) for all supported network devices with a specific vendorID.

The relevant section from the performance profile is:

apiVersion: performance.openshift.io/v2
metadata:
  name: performance
spec:
  kind: PerformanceProfile
  spec:
    cpu:
      reserved: 0-1  #total = 2
      isolated: 2-8
    net:
      userLevelNetworking: true
      devices:
      - vendorID = 0x1af4
# ...

Display the status of the queues associated with a device using the following command:
Note
Run this command on the node where the performance profile was applied.
```
$ ethtool -l <device>
```

Verify the queue status after the profile is applied:

$ ethtool -l ens4

Example output

Channel parameters for ens4:
Pre-set maximums:
RX:         0
TX:         0
Other:      0
Combined:   4
Current hardware settings:
RX:         0
TX:         0
Other:      0
Combined:   2 1

1: The total count of reserved CPUs for all supported devices with vendorID=0x1af4 is 2. For example, if there is another network device ens2 with vendorID=0x1af4 it will also have total net queues of 2. This matches what is configured in the performance profile.

Example 3

In this example, the net queue count is set to the reserved CPU count (2) for all supported network devices that match any of the defined device identifiers.

The command udevadm info provides a detailed report on a device. In this example the devices are:

# udevadm info -p /sys/class/net/ens4
...
E: ID_MODEL_ID=0x1000
E: ID_VENDOR_ID=0x1af4
E: INTERFACE=ens4
...

# udevadm info -p /sys/class/net/eth0
...
E: ID_MODEL_ID=0x1002
E: ID_VENDOR_ID=0x1001
E: INTERFACE=eth0
...

Set the net queues to 2 for a device with interfaceName equal to eth0 and any devices that have a vendorID=0x1af4 with the following performance profile:

apiVersion: performance.openshift.io/v2
metadata:
  name: performance
spec:
  kind: PerformanceProfile
    spec:
      cpu:
        reserved: 0-1  #total = 2
        isolated: 2-8
      net:
        userLevelNetworking: true
        devices:
        - interfaceName = eth0
        - vendorID = 0x1af4
...

Verify the queue status after the profile is applied:
```
$ ethtool -l ens4
```
Example output
```
Channel parameters for ens4:
Pre-set maximums:
RX:         0
TX:         0
Other:      0
Combined:   4
Current hardware settings:
RX:         0
TX:         0
Other:      0
Combined:   2 1
```
1
The total count of reserved CPUs for all supported devices with vendorID=0x1af4 is set to 2. For example, if there is another network device ens2 with vendorID=0x1af4, it will also have the total net queues set to 2. Similarly, a device with interfaceName equal to eth0 will have total net queues set to 2.

14.2.9.3. Logging associated with adjusting NIC queues

Log messages detailing the assigned devices are recorded in the respective Tuned daemon logs. The following messages might be recorded to the /var/log/tuned/tuned.log file:

An INFO message is recorded detailing the successfully assigned devices:

INFO tuned.plugins.base: instance net_test (net): assigning devices ens1, ens2, ens3

A WARNING message is recorded if none of the devices can be assigned:

WARNING  tuned.plugins.base: instance net_test: no matching devices available

14.3. Provisioning real-time and low latency workloads

Many organizations need high performance computing and low, predictable latency, especially in the financial and telecommunications industries.

OpenShift Container Platform provides the Node Tuning Operator to implement automatic tuning to achieve low latency performance and consistent response time for OpenShift Container Platform applications. You use the performance profile configuration to make these changes. You can update the kernel to kernel-rt, reserve CPUs for cluster and operating system housekeeping duties, including pod infra containers, isolate CPUs for application containers to run the workloads, and disable unused CPUs to reduce power consumption.

Note

When writing your applications, follow the general recommendations described in RHEL for Real Time processes and threads.

Additional resources

Tuning nodes for low latency with the performance profile

14.3.1. Scheduling a low latency workload onto a worker with real-time capabilities

You can schedule low latency workloads onto a worker node where a performance profile that configures real-time capabilities is applied.

Note

To schedule the workload on specific nodes, use label selectors in the Pod custom resource (CR). The label selectors must match the nodes that are attached to the machine config pool that was configured for low latency by the Node Tuning Operator.

Prerequisites

You have installed the OpenShift CLI (oc).
You have logged in as a user with cluster-admin privileges.
You have applied a performance profile in the cluster that tunes worker nodes for low latency workloads.

Procedure

Create a Pod CR for the low latency workload and apply it in the cluster, for example:

Example Pod spec configured to use real-time processing

apiVersion: v1
kind: Pod
metadata:
  name: dynamic-low-latency-pod
  annotations:
    cpu-quota.crio.io: "disable" 1
    cpu-load-balancing.crio.io: "disable" 2
    irq-load-balancing.crio.io: "disable" 3
spec:
  securityContext:
    runAsNonRoot: true
    seccompProfile:
      type: RuntimeDefault
  containers:
  - name: dynamic-low-latency-pod
    image: "registry.redhat.io/openshift4/cnf-tests-rhel8:v4.14"
    command: ["sleep", "10h"]
    resources:
      requests:
        cpu: 2
        memory: "200M"
      limits:
        cpu: 2
        memory: "200M"
    securityContext:
      allowPrivilegeEscalation: false
      capabilities:
        drop: [ALL]
  nodeSelector:
    node-role.kubernetes.io/worker-cnf: "" 4
  runtimeClassName: performance-dynamic-low-latency-profile 5
# ...

1: Disables the CPU completely fair scheduler (CFS) quota at the pod run time.
2: Disables CPU load balancing.
3: Opts the pod out of interrupt handling on the node.
4: The nodeSelector label must match the label that you specify in the Node CR.
5: runtimeClassName must match the name of the performance profile configured in the cluster.

Enter the pod runtimeClassName in the form performance-<profile_name>, where <profile_name> is the name from the PerformanceProfile YAML. In the previous example, the name is performance-dynamic-low-latency-profile.

Ensure the pod is running correctly. Status should be running, and the correct cnf-worker node should be set:

$ oc get pod -o wide

Expected output

NAME                     READY   STATUS    RESTARTS   AGE     IP           NODE
dynamic-low-latency-pod  1/1     Running   0          5h33m   10.131.0.10  cnf-worker.example.com

Get the CPUs that the pod configured for IRQ dynamic load balancing runs on:

$ oc exec -it dynamic-low-latency-pod -- /bin/bash -c "grep Cpus_allowed_list /proc/self/status | awk '{print $2}'"

Expected output

Cpus_allowed_list:  2-3

Verification

Ensure the node configuration is applied correctly.

Log in to the node to verify the configuration.
```
$ oc debug node/<node-name>
```
Verify that you can use the node file system:
```
sh-4.4# chroot /host
```
Expected output
```
sh-4.4#
```
Ensure the default system CPU affinity mask does not include the dynamic-low-latency-pod CPUs, for example, CPUs 2 and 3.
```
sh-4.4# cat /proc/irq/default_smp_affinity
```
Example output
```
33
```

Ensure the system IRQs are not configured to run on the dynamic-low-latency-pod CPUs:

sh-4.4# find /proc/irq/ -name smp_affinity_list -exec sh -c 'i="$1"; mask=$(cat $i); file=$(echo $i); echo $file: $mask' _ {} \;

Example output

/proc/irq/0/smp_affinity_list: 0-5
/proc/irq/1/smp_affinity_list: 5
/proc/irq/2/smp_affinity_list: 0-5
/proc/irq/3/smp_affinity_list: 0-5
/proc/irq/4/smp_affinity_list: 0
/proc/irq/5/smp_affinity_list: 0-5
/proc/irq/6/smp_affinity_list: 0-5
/proc/irq/7/smp_affinity_list: 0-5
/proc/irq/8/smp_affinity_list: 4
/proc/irq/9/smp_affinity_list: 4
/proc/irq/10/smp_affinity_list: 0-5
/proc/irq/11/smp_affinity_list: 0
/proc/irq/12/smp_affinity_list: 1
/proc/irq/13/smp_affinity_list: 0-5
/proc/irq/14/smp_affinity_list: 1
/proc/irq/15/smp_affinity_list: 0
/proc/irq/24/smp_affinity_list: 1
/proc/irq/25/smp_affinity_list: 1
/proc/irq/26/smp_affinity_list: 1
/proc/irq/27/smp_affinity_list: 5
/proc/irq/28/smp_affinity_list: 1
/proc/irq/29/smp_affinity_list: 0
/proc/irq/30/smp_affinity_list: 0-5

Warning

When you tune nodes for low latency, the usage of execution probes in conjunction with applications that require guaranteed CPUs can cause latency spikes. Use other probes, such as a properly configured set of network probes, as an alternative.

Additional resources

14.3.2. Creating a pod with a guaranteed QoS class

Keep the following in mind when you create a pod that is given a QoS class of Guaranteed:

Every container in the pod must have a memory limit and a memory request, and they must be the same.
Every container in the pod must have a CPU limit and a CPU request, and they must be the same.

The following example shows the configuration file for a pod that has one container. The container has a memory limit and a memory request, both equal to 200 MiB. The container has a CPU limit and a CPU request, both equal to 1 CPU.

apiVersion: v1
kind: Pod
metadata:
  name: qos-demo
  namespace: qos-example
spec:
  securityContext:
    runAsNonRoot: true
    seccompProfile:
      type: RuntimeDefault
  containers:
  - name: qos-demo-ctr
    image: <image-pull-spec>
    resources:
      limits:
        memory: "200Mi"
        cpu: "1"
      requests:
        memory: "200Mi"
        cpu: "1"
    securityContext:
      allowPrivilegeEscalation: false
      capabilities:
        drop: [ALL]

Create the pod:

$ oc  apply -f qos-pod.yaml --namespace=qos-example

View detailed information about the pod:
```
$ oc get pod qos-demo --namespace=qos-example --output=yaml
```
Example output
```
spec:
  containers:
    ...
status:
  qosClass: Guaranteed
```
Note
If you specify a memory limit for a container, but do not specify a memory request, OpenShift Container Platform automatically assigns a memory request that matches the limit. Similarly, if you specify a CPU limit for a container, but do not specify a CPU request, OpenShift Container Platform automatically assigns a CPU request that matches the limit.

14.3.3. Disabling CPU load balancing in a Pod

Functionality to disable or enable CPU load balancing is implemented on the CRI-O level. The code under the CRI-O disables or enables CPU load balancing only when the following requirements are met.

The pod must use the performance-<profile-name> runtime class. You can get the proper name by looking at the status of the performance profile, as shown here:
```
apiVersion: performance.openshift.io/v2
kind: PerformanceProfile
...
status:
  ...
  runtimeClass: performance-manual
```

The Node Tuning Operator is responsible for the creation of the high-performance runtime handler config snippet under relevant nodes and for creation of the high-performance runtime class under the cluster. It will have the same content as the default runtime handler except that it enables the CPU load balancing configuration functionality.

To disable the CPU load balancing for the pod, the Pod specification must include the following fields:

apiVersion: v1
kind: Pod
metadata:
  #...
  annotations:
    #...
    cpu-load-balancing.crio.io: "disable"
    #...
  #...
spec:
  #...
  runtimeClassName: performance-<profile_name>
  #...

Note

Only disable CPU load balancing when the CPU manager static policy is enabled and for pods with guaranteed QoS that use whole CPUs. Otherwise, disabling CPU load balancing can affect the performance of other containers in the cluster.

14.3.4. Disabling power saving mode for high priority pods

You can configure pods to ensure that high priority workloads are unaffected when you configure power saving for the node that the workloads run on.

When you configure a node with a power saving configuration, you must configure high priority workloads with performance configuration at the pod level, which means that the configuration applies to all the cores used by the pod.

By disabling P-states and C-states at the pod level, you can configure high priority workloads for best performance and lowest latency.

Table 14.5. Configuration for high priority workloads
Annotation	Possible Values	Description
`cpu-c-states.crio.io:`	`"enable"` `"disable"` `"max_latency:microseconds"`	This annotation allows you to enable or disable C-states for each CPU. Alternatively, you can also specify a maximum latency in microseconds for the C-states. For example, enable C-states with a maximum latency of 10 microseconds with the setting `cpu-c-states.crio.io`: `"max_latency:10"`. Set the value to `"disable"` to provide the best performance for a pod.
`cpu-freq-governor.crio.io:`	Any supported `cpufreq governor`.	Sets the `cpufreq` governor for each CPU. The `"performance"` governor is recommended for high priority workloads.

Prerequisites

You have configured power saving in the performance profile for the node where the high priority workload pods are scheduled.

Procedure

Add the required annotations to your high priority workload pods. The annotations override the default settings.

Example high priority workload annotation

apiVersion: v1
kind: Pod
metadata:
  #...
  annotations:
    #...
    cpu-c-states.crio.io: "disable"
    cpu-freq-governor.crio.io: "performance"
    #...
  #...
spec:
  #...
  runtimeClassName: performance-<profile_name>
  #...

Restart the pods to apply the annotation.

Additional resources

Configuring power saving for nodes that run colocated high and low priority workloads

14.3.5. Disabling CPU CFS quota

To eliminate CPU throttling for pinned pods, create a pod with the cpu-quota.crio.io: "disable" annotation. This annotation disables the CPU completely fair scheduler (CFS) quota when the pod runs.

Example pod specification with cpu-quota.crio.io disabled

apiVersion: v1
kind: Pod
metadata:
  annotations:
      cpu-quota.crio.io: "disable"
spec:
    runtimeClassName: performance-<profile_name>
#...

Note

Only disable CPU CFS quota when the CPU manager static policy is enabled and for pods with guaranteed QoS that use whole CPUs. For example, pods that contain CPU-pinned containers. Otherwise, disabling CPU CFS quota can affect the performance of other containers in the cluster.

Additional resources

Recommended firmware configuration for vDU cluster hosts

14.3.6. Disabling interrupt processing for CPUs where pinned containers are running

To achieve low latency for workloads, some containers require that the CPUs they are pinned to do not process device interrupts. A pod annotation, irq-load-balancing.crio.io, is used to define whether device interrupts are processed or not on the CPUs where the pinned containers are running. When configured, CRI-O disables device interrupts where the pod containers are running.

To disable interrupt processing for CPUs where containers belonging to individual pods are pinned, ensure that globallyDisableIrqLoadBalancing is set to false in the performance profile. Then, in the pod specification, set the irq-load-balancing.crio.io pod annotation to disable.

The following pod specification contains this annotation:

apiVersion: performance.openshift.io/v2
kind: Pod
metadata:
  annotations:
      irq-load-balancing.crio.io: "disable"
spec:
    runtimeClassName: performance-<profile_name>
...

Additional resources

Managing device interrupt processing for guaranteed pod isolated CPUs

14.4. Debugging low latency node tuning status

Use the PerformanceProfile custom resource (CR) status fields for reporting tuning status and debugging latency issues in the cluster node.

14.4.1. Debugging low latency CNF tuning status

The PerformanceProfile custom resource (CR) contains status fields for reporting tuning status and debugging latency degradation issues. These fields report on conditions that describe the state of the operator’s reconciliation functionality.

A typical issue can arise when the status of machine config pools that are attached to the performance profile are in a degraded state, causing the PerformanceProfile status to degrade. In this case, the machine config pool issues a failure message.

The Node Tuning Operator contains the performanceProfile.spec.status.Conditions status field:

Status:
  Conditions:
    Last Heartbeat Time:   2020-06-02T10:01:24Z
    Last Transition Time:  2020-06-02T10:01:24Z
    Status:                True
    Type:                  Available
    Last Heartbeat Time:   2020-06-02T10:01:24Z
    Last Transition Time:  2020-06-02T10:01:24Z
    Status:                True
    Type:                  Upgradeable
    Last Heartbeat Time:   2020-06-02T10:01:24Z
    Last Transition Time:  2020-06-02T10:01:24Z
    Status:                False
    Type:                  Progressing
    Last Heartbeat Time:   2020-06-02T10:01:24Z
    Last Transition Time:  2020-06-02T10:01:24Z
    Status:                False
    Type:                  Degraded

The Status field contains Conditions that specify Type values that indicate the status of the performance profile:

Available

All machine configs and Tuned profiles have been created successfully and are available for cluster components are responsible to process them (NTO, MCO, Kubelet).

Upgradeable

Indicates whether the resources maintained by the Operator are in a state that is safe to upgrade.

Progressing

Indicates that the deployment process from the performance profile has started.

Degraded

Indicates an error if:

Validation of the performance profile has failed.
Creation of all relevant components did not complete successfully.

Each of these types contain the following fields:

Status: The state for the specific type (true or false).
Timestamp: The transaction timestamp.
Reason string: The machine readable reason.
Message string: The human readable reason describing the state and error details, if any.

14.4.1.1. Machine config pools

A performance profile and its created products are applied to a node according to an associated machine config pool (MCP). The MCP holds valuable information about the progress of applying the machine configurations created by performance profiles that encompass kernel args, kube config, huge pages allocation, and deployment of rt-kernel. The Performance Profile controller monitors changes in the MCP and updates the performance profile status accordingly.

The only conditions returned by the MCP to the performance profile status is when the MCP is Degraded, which leads to performanceProfile.status.condition.Degraded = true.

Example

The following example is for a performance profile with an associated machine config pool (worker-cnf) that was created for it:

The associated machine config pool is in a degraded state:

# oc get mcp

Example output

NAME         CONFIG                                                 UPDATED   UPDATING   DEGRADED   MACHINECOUNT   READYMACHINECOUNT   UPDATEDMACHINECOUNT   DEGRADEDMACHINECOUNT   AGE
master       rendered-master-2ee57a93fa6c9181b546ca46e1571d2d       True      False      False      3              3                   3                     0                      2d21h
worker       rendered-worker-d6b2bdc07d9f5a59a6b68950acf25e5f       True      False      False      2              2                   2                     0                      2d21h
worker-cnf   rendered-worker-cnf-6c838641b8a08fff08dbd8b02fb63f7c   False     True       True       2              1                   1                     1                      2d20h

The describe section of the MCP shows the reason:

# oc describe mcp worker-cnf

Example output

  Message:               Node node-worker-cnf is reporting: "prepping update:
  machineconfig.machineconfiguration.openshift.io \"rendered-worker-cnf-40b9996919c08e335f3ff230ce1d170\" not
  found"
    Reason:                1 nodes are reporting degraded status on sync

The degraded state should also appear under the performance profile status field marked as degraded = true:

# oc describe performanceprofiles performance

Example output

Message: Machine config pool worker-cnf Degraded Reason: 1 nodes are reporting degraded status on sync.
Machine config pool worker-cnf Degraded Message: Node yquinn-q8s5v-w-b-z5lqn.c.openshift-gce-devel.internal is
reporting: "prepping update: machineconfig.machineconfiguration.openshift.io
\"rendered-worker-cnf-40b9996919c08e335f3ff230ce1d170\" not found".    Reason:  MCPDegraded
   Status:  True
   Type:    Degraded

14.4.2. Collecting low latency tuning debugging data for Red Hat Support

When opening a support case, it is helpful to provide debugging information about your cluster to Red Hat Support.

The must-gather tool enables you to collect diagnostic information about your OpenShift Container Platform cluster, including node tuning, NUMA topology, and other information needed to debug issues with low latency setup.

For prompt support, supply diagnostic information for both OpenShift Container Platform and low latency tuning.

14.4.2.1. About the must-gather tool

The oc adm must-gather CLI command collects the information from your cluster that is most likely needed for debugging issues, such as:

Resource definitions
Audit logs
Service logs

You can specify one or more images when you run the command by including the --image argument. When you specify an image, the tool collects data related to that feature or product. When you run oc adm must-gather, a new pod is created on the cluster. The data is collected on that pod and saved in a new directory that starts with must-gather.local. This directory is created in your current working directory.

14.4.2.2. Gathering low latency tuning data

Use the oc adm must-gather CLI command to collect information about your cluster, including features and objects associated with low latency tuning, including:

The Node Tuning Operator namespaces and child objects.
MachineConfigPool and associated MachineConfig objects.
The Node Tuning Operator and associated Tuned objects.
Linux kernel command line options.
CPU and NUMA topology
Basic PCI device information and NUMA locality.

Prerequisites

Access to the cluster as a user with the cluster-admin role.
The OpenShift Container Platform CLI (oc) installed.

Procedure

Navigate to the directory where you want to store the must-gather data.

Collect debugging information by running the following command:

$ oc adm must-gather

Example output

[must-gather      ] OUT Using must-gather plug-in image: quay.io/openshift-release
When opening a support case, bugzilla, or issue please include the following summary data along with any other requested information:
ClusterID: 829er0fa-1ad8-4e59-a46e-2644921b7eb6
ClusterVersion: Stable at "<cluster_version>"
ClusterOperators:
	All healthy and stable


[must-gather      ] OUT namespace/openshift-must-gather-8fh4x created
[must-gather      ] OUT clusterrolebinding.rbac.authorization.k8s.io/must-gather-rhlgc created
[must-gather-5564g] POD 2023-07-17T10:17:37.610340849Z Gathering data for ns/openshift-cluster-version...
[must-gather-5564g] POD 2023-07-17T10:17:38.786591298Z Gathering data for ns/default...
[must-gather-5564g] POD 2023-07-17T10:17:39.117418660Z Gathering data for ns/openshift...
[must-gather-5564g] POD 2023-07-17T10:17:39.447592859Z Gathering data for ns/kube-system...
[must-gather-5564g] POD 2023-07-17T10:17:39.803381143Z Gathering data for ns/openshift-etcd...

...

Reprinting Cluster State:
When opening a support case, bugzilla, or issue please include the following summary data along with any other requested information:
ClusterID: 829er0fa-1ad8-4e59-a46e-2644921b7eb6
ClusterVersion: Stable at "<cluster_version>"
ClusterOperators:
	All healthy and stable

Create a compressed file from the must-gather directory that was created in your working directory. For example, on a computer that uses a Linux operating system, run the following command:
```
$ tar cvaf must-gather.tar.gz must-gather-local.54213423446277122891
```
1
Replace must-gather-local.5421342344627712289// with the directory name created by the must-gather tool.
Note
Create a compressed file to attach the data to a support case or to use with the Performance Profile Creator wrapper script when you create a performance profile.
Attach the compressed file to your support case on the Red Hat Customer Portal.

Additional resources

14.5. Performing latency tests for platform verification

You can use the Cloud-native Network Functions (CNF) tests image to run latency tests on a CNF-enabled OpenShift Container Platform cluster, where all the components required for running CNF workloads are installed. Run the latency tests to validate node tuning for your workload.

The cnf-tests container image is available at registry.redhat.io/openshift4/cnf-tests-rhel8:v4.14.

Important

The cnf-tests image also includes several tests that are not supported by Red Hat at this time. Only the latency tests are supported by Red Hat.

14.5.1. Prerequisites for running latency tests

Your cluster must meet the following requirements before you can run the latency tests:

You have configured a performance profile with the Node Tuning Operator.
You have applied all the required CNF configurations in the cluster.
You have a pre-existing MachineConfigPool CR applied in the cluster. The default worker pool is worker-cnf.

Additional resources

Scheduling a workload onto a worker with real-time capabilities

14.5.2. About discovery mode for latency tests

Use discovery mode to validate the functionality of a cluster without altering its configuration. Existing environment configurations are used for the tests. The tests can find the configuration items needed and use those items to execute the tests. If resources needed to run a specific test are not found, the test is skipped, providing an appropriate message to the user. After the tests are finished, no cleanup of the preconfigured configuration items is done, and the test environment can be immediately used for another test run.

Important

When running the latency tests, always run the tests with -e DISCOVERY_MODE=true and -ginkgo.focus set to the appropriate latency test. If you do not run the latency tests in discovery mode, your existing live cluster performance profile configuration will be modified by the test run.

Limiting the nodes used during tests

The nodes on which the tests are executed can be limited by specifying a NODES_SELECTOR environment variable, for example, -e NODES_SELECTOR=node-role.kubernetes.io/worker-cnf. Any resources created by the test are limited to nodes with matching labels.

Note

If you want to override the default worker pool, pass the -e ROLE_WORKER_CNF=<custom_worker_pool> variable to the command specifying an appropriate label.

14.5.3. Measuring latency

The cnf-tests image uses three tools to measure the latency of the system:

hwlatdetect
cyclictest
oslat

Each tool has a specific use. Use the tools in sequence to achieve reliable test results.

hwlatdetect: Measures the baseline that the bare-metal hardware can achieve. Before proceeding with the next latency test, ensure that the latency reported by hwlatdetect meets the required threshold because you cannot fix hardware latency spikes by operating system tuning.
cyclictest: Verifies the real-time kernel scheduler latency after hwlatdetect passes validation. The cyclictest tool schedules a repeated timer and measures the difference between the desired and the actual trigger times. The difference can uncover basic issues with the tuning caused by interrupts or process priorities. The tool must run on a real-time kernel.
oslat: Behaves similarly to a CPU-intensive DPDK application and measures all the interruptions and disruptions to the busy loop that simulates CPU heavy data processing.

The tests introduce the following environment variables:

Table 14.6. Latency test environment variables
Environment variables	Description
`LATENCY_TEST_DELAY`	Specifies the amount of time in seconds after which the test starts running. You can use the variable to allow the CPU manager reconcile loop to update the default CPU pool. The default value is 0.
`LATENCY_TEST_CPUS`	Specifies the number of CPUs that the pod running the latency tests uses. If you do not set the variable, the default configuration includes all isolated CPUs.
`LATENCY_TEST_RUNTIME`	Specifies the amount of time in seconds that the latency test must run. The default value is 300 seconds. Note To prevent the Ginkgo 2.0 test suite from timing out before the latency tests complete, set the `-ginkgo.timeout` flag to a value greater than `LATENCY_TEST_RUNTIME` + 2 minutes. If you also set a `LATENCY_TEST_DELAY` value then you must set `-ginkgo.timeout` to a value greater than `LATENCY_TEST_RUNTIME` + `LATENCY_TEST_DELAY` + 2 minutes. The default timeout value for the Ginkgo 2.0 test suite is 1 hour.
`HWLATDETECT_MAXIMUM_LATENCY`	Specifies the maximum acceptable hardware latency in microseconds for the workload and operating system. If you do not set the value of `HWLATDETECT_MAXIMUM_LATENCY` or `MAXIMUM_LATENCY`, the tool compares the default expected threshold (20μs) and the actual maximum latency in the tool itself. Then, the test fails or succeeds accordingly.
`CYCLICTEST_MAXIMUM_LATENCY`	Specifies the maximum latency in microseconds that all threads expect before waking up during the `cyclictest` run. If you do not set the value of `CYCLICTEST_MAXIMUM_LATENCY` or `MAXIMUM_LATENCY`, the tool skips the comparison of the expected and the actual maximum latency.
`OSLAT_MAXIMUM_LATENCY`	Specifies the maximum acceptable latency in microseconds for the `oslat` test results. If you do not set the value of `OSLAT_MAXIMUM_LATENCY` or `MAXIMUM_LATENCY`, the tool skips the comparison of the expected and the actual maximum latency.
`MAXIMUM_LATENCY`	Unified variable that specifies the maximum acceptable latency in microseconds. Applicable for all available latency tools.
`LATENCY_TEST_RUN`	Boolean parameter that indicates whether the tests should run. `LATENCY_TEST_RUN` is set to `false` by default. To run the latency tests, set this value to `true`.

Note

Variables that are specific to a latency tool take precedence over unified variables. For example, if OSLAT_MAXIMUM_LATENCY is set to 30 microseconds and MAXIMUM_LATENCY is set to 10 microseconds, the oslat test will run with maximum acceptable latency of 30 microseconds.

14.5.4. Running the latency tests

Run the cluster latency tests to validate node tuning for your Cloud-native Network Functions (CNF) workload.

Important

Always run the latency tests with DISCOVERY_MODE=true set. If you don’t, the test suite will make changes to the running cluster configuration.

Note

When executing podman commands as a non-root or non-privileged user, mounting paths can fail with permission denied errors. To make the podman command work, append :Z to the volumes creation; for example, -v $(pwd)/:/kubeconfig:Z. This allows podman to do the proper SELinux relabeling.

Procedure

Open a shell prompt in the directory containing the kubeconfig file.
You provide the test image with a kubeconfig file in current directory and its related $KUBECONFIG environment variable, mounted through a volume. This allows the running container to use the kubeconfig file from inside the container.

Run the latency tests by entering the following command:

$ podman run -v $(pwd)/:/kubeconfig:Z -e KUBECONFIG=/kubeconfig/kubeconfig \
-e LATENCY_TEST_RUN=true -e DISCOVERY_MODE=true -e FEATURES=performance registry.redhat.io/openshift4/cnf-tests-rhel8:v4.14 \
/usr/bin/test-run.sh -ginkgo.focus="\[performance\]\ Latency\ Test" --ginkgo.timeout="24h"

Optional: Append -ginkgo.dryRun to run the latency tests in dry-run mode. This is useful for checking what the tests run.
Optional: Append -ginkgo.v to run the tests with increased verbosity.

Optional: To run the latency tests against a specific performance profile, run the following command, substituting appropriate values:

$ podman run -v $(pwd)/:/kubeconfig:Z -e KUBECONFIG=/kubeconfig/kubeconfig \
-e LATENCY_TEST_RUN=true -e FEATURES=performance -e LATENCY_TEST_RUNTIME=600 -e MAXIMUM_LATENCY=20 \
-e PERF_TEST_PROFILE=<performance_profile> registry.redhat.io/openshift4/cnf-tests-rhel8:v4.14 \
/usr/bin/test-run.sh -ginkgo.focus="[performance]\ Latency\ Test"

where:

<performance_profile>: Is the name of the performance profile you want to run the latency tests against.

Optional: Append --ginkgo.timeout="24h" flag to ensure the Ginkgo 2.0 test suite does not timeout before the latency tests complete.
Important
For valid latency test results, run the tests for at least 12 hours.

14.5.4.1. Running hwlatdetect

The hwlatdetect tool is available in the rt-kernel package with a regular subscription of Red Hat Enterprise Linux (RHEL) 9.x.

Important

Always run the latency tests with DISCOVERY_MODE=true set. If you don’t, the test suite will make changes to the running cluster configuration.

Note

Prerequisites

You have installed the real-time kernel in the cluster.
You have logged in to registry.redhat.io with your Customer Portal credentials.

Procedure

To run the hwlatdetect tests, run the following command, substituting variable values as appropriate:

$ podman run -v $(pwd)/:/kubeconfig:Z -e KUBECONFIG=/kubeconfig/kubeconfig \
-e LATENCY_TEST_RUN=true -e DISCOVERY_MODE=true -e FEATURES=performance -e ROLE_WORKER_CNF=worker-cnf \
-e LATENCY_TEST_RUNTIME=600 -e MAXIMUM_LATENCY=20 \
registry.redhat.io/openshift4/cnf-tests-rhel8:v4.14 \
/usr/bin/test-run.sh -ginkgo.v -ginkgo.focus="hwlatdetect" --ginkgo.timeout="24h"

The hwlatdetect test runs for 10 minutes (600 seconds). The test runs successfully when the maximum observed latency is lower than MAXIMUM_LATENCY (20 μs).

If the results exceed the latency threshold, the test fails.

Important

For valid results, the test should run for at least 12 hours.

Example failure output

running /usr/bin/cnftests -ginkgo.v -ginkgo.focus=hwlatdetect
I0908 15:25:20.023712      27 request.go:601] Waited for 1.046586367s due to client-side throttling, not priority and fairness, request: GET:https://api.hlxcl6.lab.eng.tlv2.redhat.com:6443/apis/imageregistry.operator.openshift.io/v1?timeout=32s
Running Suite: CNF Features e2e integration tests
=================================================
Random Seed: 1662650718
Will run 1 of 194 specs

[...]

• Failure [283.574 seconds]
[performance] Latency Test
/remote-source/app/vendor/github.com/openshift/cluster-node-tuning-operator/test/e2e/performanceprofile/functests/4_latency/latency.go:62
  with the hwlatdetect image
  /remote-source/app/vendor/github.com/openshift/cluster-node-tuning-operator/test/e2e/performanceprofile/functests/4_latency/latency.go:228
    should succeed [It]
    /remote-source/app/vendor/github.com/openshift/cluster-node-tuning-operator/test/e2e/performanceprofile/functests/4_latency/latency.go:236

    Log file created at: 2022/09/08 15:25:27
    Running on machine: hwlatdetect-b6n4n
    Binary: Built with gc go1.17.12 for linux/amd64
    Log line format: [IWEF]mmdd hh:mm:ss.uuuuuu threadid file:line] msg
    I0908 15:25:27.160620       1 node.go:39] Environment information: /proc/cmdline: BOOT_IMAGE=(hd1,gpt3)/ostree/rhcos-c6491e1eedf6c1f12ef7b95e14ee720bf48359750ac900b7863c625769ef5fb9/vmlinuz-4.18.0-372.19.1.el8_6.x86_64 random.trust_cpu=on console=tty0 console=ttyS0,115200n8 ignition.platform.id=metal ostree=/ostree/boot.1/rhcos/c6491e1eedf6c1f12ef7b95e14ee720bf48359750ac900b7863c625769ef5fb9/0 ip=dhcp root=UUID=5f80c283-f6e6-4a27-9b47-a287157483b2 rw rootflags=prjquota boot=UUID=773bf59a-bafd-48fc-9a87-f62252d739d3 skew_tick=1 nohz=on rcu_nocbs=0-3 tuned.non_isolcpus=0000ffff,ffffffff,fffffff0 systemd.cpu_affinity=4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79 intel_iommu=on iommu=pt isolcpus=managed_irq,0-3 nohz_full=0-3 tsc=nowatchdog nosoftlockup nmi_watchdog=0 mce=off skew_tick=1 rcutree.kthread_prio=11 + +
    I0908 15:25:27.160830       1 node.go:46] Environment information: kernel version 4.18.0-372.19.1.el8_6.x86_64
    I0908 15:25:27.160857       1 main.go:50] running the hwlatdetect command with arguments [/usr/bin/hwlatdetect --threshold 1 --hardlimit 1 --duration 100 --window 10000000us --width 950000us]
    F0908 15:27:10.603523       1 main.go:53] failed to run hwlatdetect command; out: hwlatdetect:  test duration 100 seconds
       detector: tracer
       parameters:
            Latency threshold: 1us 1
            Sample window:     10000000us
            Sample width:      950000us
         Non-sampling period:  9050000us
            Output File:       None

    Starting test
    test finished
    Max Latency: 326us 2
    Samples recorded: 5
    Samples exceeding threshold: 5
    ts: 1662650739.017274507, inner:6, outer:6
    ts: 1662650749.257272414, inner:14, outer:326
    ts: 1662650779.977272835, inner:314, outer:12
    ts: 1662650800.457272384, inner:3, outer:9
    ts: 1662650810.697273520, inner:3, outer:2

[...]

JUnit report was created: /junit.xml/cnftests-junit.xml


Summarizing 1 Failure:

[Fail] [performance] Latency Test with the hwlatdetect image [It] should succeed
/remote-source/app/vendor/github.com/openshift/cluster-node-tuning-operator/test/e2e/performanceprofile/functests/4_latency/latency.go:476

Ran 1 of 194 Specs in 365.797 seconds
FAIL! -- 0 Passed | 1 Failed | 0 Pending | 193 Skipped
--- FAIL: TestTest (366.08s)
FAIL

1: You can configure the latency threshold by using the MAXIMUM_LATENCY or the HWLATDETECT_MAXIMUM_LATENCY environment variables.
2: The maximum latency value measured during the test.

Example hwlatdetect test results

You can capture the following types of results:

Rough results that are gathered after each run to create a history of impact on any changes made throughout the test.
The combined set of the rough tests with the best results and configuration settings.

Example of good results

hwlatdetect: test duration 3600 seconds
detector: tracer
parameters:
Latency threshold: 10us
Sample window: 1000000us
Sample width: 950000us
Non-sampling period: 50000us
Output File: None

Starting test
test finished
Max Latency: Below threshold
Samples recorded: 0

The hwlatdetect tool only provides output if the sample exceeds the specified threshold.

Example of bad results

hwlatdetect: test duration 3600 seconds
detector: tracer
parameters:Latency threshold: 10usSample window: 1000000us
Sample width: 950000usNon-sampling period: 50000usOutput File: None

Starting tests:1610542421.275784439, inner:78, outer:81
ts: 1610542444.330561619, inner:27, outer:28
ts: 1610542445.332549975, inner:39, outer:38
ts: 1610542541.568546097, inner:47, outer:32
ts: 1610542590.681548531, inner:13, outer:17
ts: 1610543033.818801482, inner:29, outer:30
ts: 1610543080.938801990, inner:90, outer:76
ts: 1610543129.065549639, inner:28, outer:39
ts: 1610543474.859552115, inner:28, outer:35
ts: 1610543523.973856571, inner:52, outer:49
ts: 1610543572.089799738, inner:27, outer:30
ts: 1610543573.091550771, inner:34, outer:28
ts: 1610543574.093555202, inner:116, outer:63

The output of hwlatdetect shows that multiple samples exceed the threshold. However, the same output can indicate different results based on the following factors:

The duration of the test
The number of CPU cores
The host firmware settings

Warning

Before proceeding with the next latency test, ensure that the latency reported by hwlatdetect meets the required threshold. Fixing latencies introduced by hardware might require you to contact the system vendor support.

Not all latency spikes are hardware related. Ensure that you tune the host firmware to meet your workload requirements. For more information, see Setting firmware parameters for system tuning.

14.5.4.2. Running cyclictest

The cyclictest tool measures the real-time kernel scheduler latency on the specified CPUs.

Important

Always run the latency tests with DISCOVERY_MODE=true set. If you don’t, the test suite will make changes to the running cluster configuration.

Note

Prerequisites

You have logged in to registry.redhat.io with your Customer Portal credentials.
You have installed the real-time kernel in the cluster.
You have applied a cluster performance profile by using Node Tuning Operator.

Procedure

To perform the cyclictest, run the following command, substituting variable values as appropriate:

$ podman run -v $(pwd)/:/kubeconfig:Z -e KUBECONFIG=/kubeconfig/kubeconfig \
-e LATENCY_TEST_RUN=true -e DISCOVERY_MODE=true -e FEATURES=performance -e ROLE_WORKER_CNF=worker-cnf \
-e LATENCY_TEST_CPUS=10 -e LATENCY_TEST_RUNTIME=600 -e MAXIMUM_LATENCY=20 \
registry.redhat.io/openshift4/cnf-tests-rhel8:v4.14 \
/usr/bin/test-run.sh -ginkgo.v -ginkgo.focus="cyclictest" --ginkgo.timeout="24h"

The command runs the cyclictest tool for 10 minutes (600 seconds). The test runs successfully when the maximum observed latency is lower than MAXIMUM_LATENCY (in this example, 20 μs). Latency spikes of 20 μs and above are generally not acceptable for telco RAN workloads.

If the results exceed the latency threshold, the test fails.

Important

For valid results, the test should run for at least 12 hours.

Example failure output

running /usr/bin/cnftests -ginkgo.v -ginkgo.focus=cyclictest
I0908 13:01:59.193776      27 request.go:601] Waited for 1.046228824s due to client-side throttling, not priority and fairness, request: GET:https://api.compute-1.example.com:6443/apis/packages.operators.coreos.com/v1?timeout=32s
Running Suite: CNF Features e2e integration tests
=================================================
Random Seed: 1662642118
Will run 1 of 194 specs

[...]

Summarizing 1 Failure:

[Fail] [performance] Latency Test with the cyclictest image [It] should succeed
/remote-source/app/vendor/github.com/openshift/cluster-node-tuning-operator/test/e2e/performanceprofile/functests/4_latency/latency.go:220

Ran 1 of 194 Specs in 161.151 seconds
FAIL! -- 0 Passed | 1 Failed | 0 Pending | 193 Skipped
--- FAIL: TestTest (161.48s)
FAIL

Example cyclictest results

The same output can indicate different results for different workloads. For example, spikes up to 18μs are acceptable for 4G DU workloads, but not for 5G DU workloads.

Example of good results

running cmd: cyclictest -q -D 10m -p 1 -t 16 -a 2,4,6,8,10,12,14,16,54,56,58,60,62,64,66,68 -h 30 -i 1000 -m
# Histogram
000000 000000   000000  000000  000000  000000  000000  000000  000000  000000  000000  000000  000000  000000  000000  000000  000000
000001 000000   000000  000000  000000  000000  000000  000000  000000  000000  000000  000000  000000  000000  000000  000000  000000
000002 579506   535967  418614  573648  532870  529897  489306  558076  582350  585188  583793  223781  532480  569130  472250  576043
More histogram entries ...
# Total: 000600000 000600000 000600000 000599999 000599999 000599999 000599998 000599998 000599998 000599997 000599997 000599996 000599996 000599995 000599995 000599995
# Min Latencies: 00002 00002 00002 00002 00002 00002 00002 00002 00002 00002 00002 00002 00002 00002 00002 00002
# Avg Latencies: 00002 00002 00002 00002 00002 00002 00002 00002 00002 00002 00002 00002 00002 00002 00002 00002
# Max Latencies: 00005 00005 00004 00005 00004 00004 00005 00005 00006 00005 00004 00005 00004 00004 00005 00004
# Histogram Overflows: 00000 00000 00000 00000 00000 00000 00000 00000 00000 00000 00000 00000 00000 00000 00000 00000
# Histogram Overflow at cycle number:
# Thread 0:
# Thread 1:
# Thread 2:
# Thread 3:
# Thread 4:
# Thread 5:
# Thread 6:
# Thread 7:
# Thread 8:
# Thread 9:
# Thread 10:
# Thread 11:
# Thread 12:
# Thread 13:
# Thread 14:
# Thread 15:

Example of bad results

running cmd: cyclictest -q -D 10m -p 1 -t 16 -a 2,4,6,8,10,12,14,16,54,56,58,60,62,64,66,68 -h 30 -i 1000 -m
# Histogram
000000 000000   000000  000000  000000  000000  000000  000000  000000  000000  000000  000000  000000  000000  000000  000000  000000
000001 000000   000000  000000  000000  000000  000000  000000  000000  000000  000000  000000  000000  000000  000000  000000  000000
000002 564632   579686  354911  563036  492543  521983  515884  378266  592621  463547  482764  591976  590409  588145  589556  353518
More histogram entries ...
# Total: 000599999 000599999 000599999 000599997 000599997 000599998 000599998 000599997 000599997 000599996 000599995 000599996 000599995 000599995 000599995 000599993
# Min Latencies: 00002 00002 00002 00002 00002 00002 00002 00002 00002 00002 00002 00002 00002 00002 00002 00002
# Avg Latencies: 00002 00002 00002 00002 00002 00002 00002 00002 00002 00002 00002 00002 00002 00002 00002 00002
# Max Latencies: 00493 00387 00271 00619 00541 00513 00009 00389 00252 00215 00539 00498 00363 00204 00068 00520
# Histogram Overflows: 00001 00001 00001 00002 00002 00001 00000 00001 00001 00001 00002 00001 00001 00001 00001 00002
# Histogram Overflow at cycle number:
# Thread 0: 155922
# Thread 1: 110064
# Thread 2: 110064
# Thread 3: 110063 155921
# Thread 4: 110063 155921
# Thread 5: 155920
# Thread 6:
# Thread 7: 110062
# Thread 8: 110062
# Thread 9: 155919
# Thread 10: 110061 155919
# Thread 11: 155918
# Thread 12: 155918
# Thread 13: 110060
# Thread 14: 110060
# Thread 15: 110059 155917

14.5.4.3. Running oslat

The oslat test simulates a CPU-intensive DPDK application and measures all the interruptions and disruptions to test how the cluster handles CPU heavy data processing.

Important

Always run the latency tests with DISCOVERY_MODE=true set. If you don’t, the test suite will make changes to the running cluster configuration.

Note

Prerequisites

You have logged in to registry.redhat.io with your Customer Portal credentials.
You have applied a cluster performance profile by using the Node Tuning Operator.

Procedure

To perform the oslat test, run the following command, substituting variable values as appropriate:

$ podman run -v $(pwd)/:/kubeconfig:Z -e KUBECONFIG=/kubeconfig/kubeconfig \
-e LATENCY_TEST_RUN=true -e DISCOVERY_MODE=true -e FEATURES=performance -e ROLE_WORKER_CNF=worker-cnf \
-e LATENCY_TEST_CPUS=10 -e LATENCY_TEST_RUNTIME=600 -e MAXIMUM_LATENCY=20 \
registry.redhat.io/openshift4/cnf-tests-rhel8:v4.14 \
/usr/bin/test-run.sh -ginkgo.v -ginkgo.focus="oslat" --ginkgo.timeout="24h"

LATENCY_TEST_CPUS specifies the list of CPUs to test with the oslat command.

The command runs the oslat tool for 10 minutes (600 seconds). The test runs successfully when the maximum observed latency is lower than MAXIMUM_LATENCY (20 μs).

If the results exceed the latency threshold, the test fails.

Important

For valid results, the test should run for at least 12 hours.

Example failure output

running /usr/bin/cnftests -ginkgo.v -ginkgo.focus=oslat
I0908 12:51:55.999393      27 request.go:601] Waited for 1.044848101s due to client-side throttling, not priority and fairness, request: GET:https://compute-1.example.com:6443/apis/machineconfiguration.openshift.io/v1?timeout=32s
Running Suite: CNF Features e2e integration tests
=================================================
Random Seed: 1662641514
Will run 1 of 194 specs

[...]

• Failure [77.833 seconds]
[performance] Latency Test
/remote-source/app/vendor/github.com/openshift/cluster-node-tuning-operator/test/e2e/performanceprofile/functests/4_latency/latency.go:62
  with the oslat image
  /remote-source/app/vendor/github.com/openshift/cluster-node-tuning-operator/test/e2e/performanceprofile/functests/4_latency/latency.go:128
    should succeed [It]
    /remote-source/app/vendor/github.com/openshift/cluster-node-tuning-operator/test/e2e/performanceprofile/functests/4_latency/latency.go:153

    The current latency 304 is bigger than the expected one 1 : 1

[...]

Summarizing 1 Failure:

[Fail] [performance] Latency Test with the oslat image [It] should succeed
/remote-source/app/vendor/github.com/openshift/cluster-node-tuning-operator/test/e2e/performanceprofile/functests/4_latency/latency.go:177

Ran 1 of 194 Specs in 161.091 seconds
FAIL! -- 0 Passed | 1 Failed | 0 Pending | 193 Skipped
--- FAIL: TestTest (161.42s)
FAIL

1: In this example, the measured latency is outside the maximum allowed value.

14.5.5. Generating a latency test failure report

Use the following procedures to generate a JUnit latency test output and test failure report.

Prerequisites

You have installed the OpenShift CLI (oc).
You have logged in as a user with cluster-admin privileges.

Procedure

Create a test failure report with information about the cluster state and resources for troubleshooting by passing the --report parameter with the path to where the report is dumped:

$ podman run -v $(pwd)/:/kubeconfig:Z -v $(pwd)/reportdest:<report_folder_path> \
-e KUBECONFIG=/kubeconfig/kubeconfig  -e DISCOVERY_MODE=true -e FEATURES=performance \
registry.redhat.io/openshift4/cnf-tests-rhel8:v4.14 \
/usr/bin/test-run.sh --report <report_folder_path> \
-ginkgo.focus="\[performance\]\ Latency\ Test"

where:

<report_folder_path>: Is the path to the folder where the report is generated.

14.5.6. Generating a JUnit latency test report

Use the following procedures to generate a JUnit latency test output and test failure report.

Prerequisites

You have installed the OpenShift CLI (oc).
You have logged in as a user with cluster-admin privileges.

Procedure

Create a JUnit-compliant XML report by passing the --junit parameter together with the path to where the report is dumped:

$ podman run -v $(pwd)/:/kubeconfig:Z -v $(pwd)/junitdest:<junit_folder_path> \
-e KUBECONFIG=/kubeconfig/kubeconfig -e DISCOVERY_MODE=true -e FEATURES=performance \
registry.redhat.io/openshift4/cnf-tests-rhel8:v4.14 \
/usr/bin/test-run.sh --junit <junit_folder_path> \
-ginkgo.focus="\[performance\]\ Latency\ Test"

where:

<junit_folder_path>: Is the path to the folder where the junit report is generated

14.5.7. Running latency tests on a single-node OpenShift cluster

You can run latency tests on single-node OpenShift clusters.

Important

Always run the latency tests with DISCOVERY_MODE=true set. If you don’t, the test suite will make changes to the running cluster configuration.

Note

Prerequisites

You have installed the OpenShift CLI (oc).
You have logged in as a user with cluster-admin privileges.

Procedure

To run the latency tests on a single-node OpenShift cluster, run the following command:
```
$ podman run -v $(pwd)/:/kubeconfig:Z -e KUBECONFIG=/kubeconfig/kubeconfig \
-e DISCOVERY_MODE=true -e FEATURES=performance -e ROLE_WORKER_CNF=master \
registry.redhat.io/openshift4/cnf-tests-rhel8:v4.14 \
/usr/bin/test-run.sh -ginkgo.focus="\[performance\]\ Latency\ Test" --ginkgo.timeout="24h"
```
Note
ROLE_WORKER_CNF=master is required because master is the only machine pool to which the node belongs. For more information about setting the required MachineConfigPool for the latency tests, see "Prerequisites for running latency tests".
After running the test suite, all the dangling resources are cleaned up.

14.5.8. Running latency tests in a disconnected cluster

The CNF tests image can run tests in a disconnected cluster that is not able to reach external registries. This requires two steps:

Mirroring the cnf-tests image to the custom disconnected registry.
Instructing the tests to consume the images from the custom disconnected registry.

Mirroring the images to a custom registry accessible from the cluster

A mirror executable is shipped in the image to provide the input required by oc to mirror the test image to a local registry.

Run this command from an intermediate machine that has access to the cluster and registry.redhat.io:
```
$ podman run -v $(pwd)/:/kubeconfig:Z -e KUBECONFIG=/kubeconfig/kubeconfig \
registry.redhat.io/openshift4/cnf-tests-rhel8:v4.14 \
/usr/bin/mirror -registry <disconnected_registry> | oc image mirror -f -
```
where:
<disconnected_registry>
Is the disconnected mirror registry you have configured, for example, my.local.registry:5000/.

When you have mirrored the cnf-tests image into the disconnected registry, you must override the original registry used to fetch the images when running the tests, for example:

$ podman run -v $(pwd)/:/kubeconfig:Z -e KUBECONFIG=/kubeconfig/kubeconfig \
-e DISCOVERY_MODE=true -e FEATURES=performance -e IMAGE_REGISTRY="<disconnected_registry>" \
-e CNF_TESTS_IMAGE="cnf-tests-rhel8:v4.14" \
/usr/bin/test-run.sh -ginkgo.focus="\[performance\]\ Latency\ Test" --ginkgo.timeout="24h"

Configuring the tests to consume images from a custom registry

You can run the latency tests using a custom test image and image registry using CNF_TESTS_IMAGE and IMAGE_REGISTRY variables.

To configure the latency tests to use a custom test image and image registry, run the following command:
```
$ podman run -v $(pwd)/:/kubeconfig:Z -e KUBECONFIG=/kubeconfig/kubeconfig \
-e IMAGE_REGISTRY="<custom_image_registry>" \
-e CNF_TESTS_IMAGE="<custom_cnf-tests_image>" \
-e FEATURES=performance \
registry.redhat.io/openshift4/cnf-tests-rhel8:v4.14 /usr/bin/test-run.sh --ginkgo.timeout="24h"
```
where:
<custom_image_registry>
is the custom image registry, for example, custom.registry:5000/.
<custom_cnf-tests_image>
is the custom cnf-tests image, for example, custom-cnf-tests-image:latest.

Mirroring images to the cluster OpenShift image registry

OpenShift Container Platform provides a built-in container image registry, which runs as a standard workload on the cluster.

Procedure

Gain external access to the registry by exposing it with a route:

$ oc patch configs.imageregistry.operator.openshift.io/cluster --patch '{"spec":{"defaultRoute":true}}' --type=merge

Fetch the registry endpoint by running the following command:

$ REGISTRY=$(oc get route default-route -n openshift-image-registry --template='{{ .spec.host }}')

Create a namespace for exposing the images:
```
$ oc create ns cnftests
```

Make the image stream available to all the namespaces used for tests. This is required to allow the tests namespaces to fetch the images from the cnf-tests image stream. Run the following commands:

$ oc policy add-role-to-user system:image-puller system:serviceaccount:cnf-features-testing:default --namespace=cnftests

$ oc policy add-role-to-user system:image-puller system:serviceaccount:performance-addon-operators-testing:default --namespace=cnftests

Retrieve the docker secret name and auth token by running the following commands:

$ SECRET=$(oc -n cnftests get secret | grep builder-docker | awk {'print $1'}

$ TOKEN=$(oc -n cnftests get secret $SECRET -o jsonpath="{.data['\.dockercfg']}" | base64 --decode | jq '.["image-registry.openshift-image-registry.svc:5000"].auth')

Create a dockerauth.json file, for example:

$ echo "{\"auths\": { \"$REGISTRY\": { \"auth\": $TOKEN } }}" > dockerauth.json

Do the image mirroring:

$ podman run -v $(pwd)/:/kubeconfig:Z -e KUBECONFIG=/kubeconfig/kubeconfig \
registry.redhat.io/openshift4/cnf-tests-rhel8:4.14 \
/usr/bin/mirror -registry $REGISTRY/cnftests |  oc image mirror --insecure=true \
-a=$(pwd)/dockerauth.json -f -

Run the tests:

$ podman run -v $(pwd)/:/kubeconfig:Z -e KUBECONFIG=/kubeconfig/kubeconfig \
-e DISCOVERY_MODE=true -e FEATURES=performance -e IMAGE_REGISTRY=image-registry.openshift-image-registry.svc:5000/cnftests \
cnf-tests-local:latest /usr/bin/test-run.sh -ginkgo.focus="\[performance\]\ Latency\ Test" --ginkgo.timeout="24h"

Mirroring a different set of test images

You can optionally change the default upstream images that are mirrored for the latency tests.

Procedure

The mirror command tries to mirror the upstream images by default. This can be overridden by passing a file with the following format to the image:
```
[
    {
        "registry": "public.registry.io:5000",
        "image": "imageforcnftests:4.14"
    }
]
```

Pass the file to the mirror command, for example saving it locally as images.json. With the following command, the local path is mounted in /kubeconfig inside the container and that can be passed to the mirror command.

$ podman run -v $(pwd)/:/kubeconfig:Z -e KUBECONFIG=/kubeconfig/kubeconfig \
registry.redhat.io/openshift4/cnf-tests-rhel8:v4.14 /usr/bin/mirror \
--registry "my.local.registry:5000/" --images "/kubeconfig/images.json" \
|  oc image mirror -f -

14.5.9. Troubleshooting errors with the cnf-tests container

To run latency tests, the cluster must be accessible from within the cnf-tests container.

Prerequisites

You have installed the OpenShift CLI (oc).
You have logged in as a user with cluster-admin privileges.

Procedure

Verify that the cluster is accessible from inside the cnf-tests container by running the following command:
```
$ podman run -v $(pwd)/:/kubeconfig:Z -e KUBECONFIG=/kubeconfig/kubeconfig \
registry.redhat.io/openshift4/cnf-tests-rhel8:v4.14 \
oc get nodes
```
If this command does not work, an error related to spanning across DNS, MTU size, or firewall access might be occurring.

Chapter 15. Improving cluster stability in high latency environments using worker latency profiles

If the cluster administrator has performed latency tests for platform verification, they can discover the need to adjust the operation of the cluster to ensure stability in cases of high latency. The cluster administrator need change only one parameter, recorded in a file, which controls four parameters affecting how supervisory processes read status and interpret the health of the cluster. Changing only the one parameter provides cluster tuning in an easy, supportable manner.

The Kubelet process provides the starting point for monitoring cluster health. The Kubelet sets status values for all nodes in the OpenShift Container Platform cluster. The Kubernetes Controller Manager (kube controller) reads the status values every 10 seconds, by default. If the kube controller cannot read a node status value, it loses contact with that node after a configured period. The default behavior is:

The node controller on the control plane updates the node health to Unhealthy and marks the node Ready condition`Unknown`.
In response, the scheduler stops scheduling pods to that node.
The Node Lifecycle Controller adds a node.kubernetes.io/unreachable taint with a NoExecute effect to the node and schedules any pods on the node for eviction after five minutes, by default.

This behavior can cause problems if your network is prone to latency issues, especially if you have nodes at the network edge. In some cases, the Kubernetes Controller Manager might not receive an update from a healthy node due to network latency. The Kubelet evicts pods from the node even though the node is healthy.

To avoid this problem, you can use worker latency profiles to adjust the frequency that the Kubelet and the Kubernetes Controller Manager wait for status updates before taking action. These adjustments help to ensure that your cluster runs properly if network latency between the control plane and the worker nodes is not optimal.

These worker latency profiles contain three sets of parameters that are pre-defined with carefully tuned values to control the reaction of the cluster to increased latency. No need to experimentally find the best values manually.

You can configure worker latency profiles when installing a cluster or at any time you notice increased latency in your cluster network.

15.1. Understanding worker latency profiles

Worker latency profiles are four different categories of carefully-tuned parameters. The four parameters which implement these values are node-status-update-frequency, node-monitor-grace-period, default-not-ready-toleration-seconds and default-unreachable-toleration-seconds. These parameters can use values which allow you control the reaction of the cluster to latency issues without needing to determine the best values using manual methods.

Important

Setting these parameters manually is not supported. Incorrect parameter settings adversely affect cluster stability.

All worker latency profiles configure the following parameters:

node-status-update-frequency: Specifies how often the kubelet posts node status to the API server.
node-monitor-grace-period: Specifies the amount of time in seconds that the Kubernetes Controller Manager waits for an update from a kubelet before marking the node unhealthy and adding the node.kubernetes.io/not-ready or node.kubernetes.io/unreachable taint to the node.
default-not-ready-toleration-seconds: Specifies the amount of time in seconds after marking a node unhealthy that the Kube API Server Operator waits before evicting pods from that node.
default-unreachable-toleration-seconds: Specifies the amount of time in seconds after marking a node unreachable that the Kube API Server Operator waits before evicting pods from that node.

The following Operators monitor the changes to the worker latency profiles and respond accordingly:

The Machine Config Operator (MCO) updates the node-status-update-frequency parameter on the worker nodes.
The Kubernetes Controller Manager updates the node-monitor-grace-period parameter on the control plane nodes.
The Kubernetes API Server Operator updates the default-not-ready-toleration-seconds and default-unreachable-toleration-seconds parameters on the control plane nodes.

Although the default configuration works in most cases, OpenShift Container Platform offers two other worker latency profiles for situations where the network is experiencing higher latency than usual. The three worker latency profiles are described in the following sections:

Default worker latency profile

With the Default profile, each Kubelet updates it’s status every 10 seconds (node-status-update-frequency). The Kube Controller Manager checks the statuses of Kubelet every 5 seconds (node-monitor-grace-period).

The Kubernetes Controller Manager waits 40 seconds for a status update from Kubelet before considering the Kubelet unhealthy. If no status is made available to the Kubernetes Controller Manager, it then marks the node with the node.kubernetes.io/not-ready or node.kubernetes.io/unreachable taint and evicts the pods on that node.

If a pod on that node has the NoExecute taint, the pod is run according to tolerationSeconds. If the pod has no taint, it will be evicted in 300 seconds (default-not-ready-toleration-seconds and default-unreachable-toleration-seconds settings of the Kube API Server).

Profile	Component	Parameter	Value
Default	kubelet	`node-status-update-frequency`	10s
	Kubelet Controller Manager	`node-monitor-grace-period`	40s
	Kubernetes API Server Operator	`default-not-ready-toleration-seconds`	300s
	Kubernetes API Server Operator	`default-unreachable-toleration-seconds`	300s

Medium worker latency profile

Use the MediumUpdateAverageReaction profile if the network latency is slightly higher than usual.

The MediumUpdateAverageReaction profile reduces the frequency of kubelet updates to 20 seconds and changes the period that the Kubernetes Controller Manager waits for those updates to 2 minutes. The pod eviction period for a pod on that node is reduced to 60 seconds. If the pod has the tolerationSeconds parameter, the eviction waits for the period specified by that parameter.

The Kubernetes Controller Manager waits for 2 minutes to consider a node unhealthy. In another minute, the eviction process starts.

Profile	Component	Parameter	Value
MediumUpdateAverageReaction	kubelet	`node-status-update-frequency`	20s
	Kubelet Controller Manager	`node-monitor-grace-period`	2m
	Kubernetes API Server Operator	`default-not-ready-toleration-seconds`	60s
	Kubernetes API Server Operator	`default-unreachable-toleration-seconds`	60s

Low worker latency profile

Use the LowUpdateSlowReaction profile if the network latency is extremely high.

The LowUpdateSlowReaction profile reduces the frequency of kubelet updates to 1 minute and changes the period that the Kubernetes Controller Manager waits for those updates to 5 minutes. The pod eviction period for a pod on that node is reduced to 60 seconds. If the pod has the tolerationSeconds parameter, the eviction waits for the period specified by that parameter.

The Kubernetes Controller Manager waits for 5 minutes to consider a node unhealthy. In another minute, the eviction process starts.

Profile	Component	Parameter	Value
LowUpdateSlowReaction	kubelet	`node-status-update-frequency`	1m
	Kubelet Controller Manager	`node-monitor-grace-period`	5m
	Kubernetes API Server Operator	`default-not-ready-toleration-seconds`	60s
	Kubernetes API Server Operator	`default-unreachable-toleration-seconds`	60s

15.2. Implementing worker latency profiles at cluster creation

Important

To edit the configuration of the installer, you will first need to use the command openshift-install create manifests to create the default node manifest as well as other manifest YAML files. This file structure must exist before we can add workerLatencyProfile. The platform on which you are installing may have varying requirements. Refer to the Installing section of the documentation for your specific platform.

The workerLatencyProfile must be added to the manifest in the following sequence:

Create the manifest needed to build the cluster, using a folder name appropriate for your installation.
Create a YAML file to define config.node. The file must be in the manifests directory.
When defining workerLatencyProfile in the manifest for the first time, specify any of the profiles at cluster creation time: Default, MediumUpdateAverageReaction or LowUpdateSlowReaction.

Verification

Here is an example manifest creation showing the spec.workerLatencyProfile Default value in the manifest file:
```
$ openshift-install create manifests --dir=<cluster-install-dir>
```

Edit the manifest and add the value. In this example we use vi to show an example manifest file with the "Default" workerLatencyProfile value added:

$ vi <cluster-install-dir>/manifests/config-node-default-profile.yaml

Example output

apiVersion: config.openshift.io/v1
kind: Node
metadata:
name: cluster
spec:
workerLatencyProfile: "Default"

15.3. Using and changing worker latency profiles

To change a worker latency profile to deal with network latency, edit the node.config object to add the name of the profile. You can change the profile at any time as latency increases or decreases.

You must move one worker latency profile at a time. For example, you cannot move directly from the Default profile to the LowUpdateSlowReaction worker latency profile. You must move from the Default worker latency profile to the MediumUpdateAverageReaction profile first, then to LowUpdateSlowReaction. Similarly, when returning to the Default profile, you must move from the low profile to the medium profile first, then to Default.

Note

You can also configure worker latency profiles upon installing an OpenShift Container Platform cluster.

Procedure

To move from the default worker latency profile:

Move to the medium worker latency profile:

Edit the node.config object:
```
$ oc edit nodes.config/cluster
```

Add spec.workerLatencyProfile: MediumUpdateAverageReaction:

Example node.config object

apiVersion: config.openshift.io/v1
kind: Node
metadata:
  annotations:
    include.release.openshift.io/ibm-cloud-managed: "true"
    include.release.openshift.io/self-managed-high-availability: "true"
    include.release.openshift.io/single-node-developer: "true"
    release.openshift.io/create-only: "true"
  creationTimestamp: "2022-07-08T16:02:51Z"
  generation: 1
  name: cluster
  ownerReferences:
  - apiVersion: config.openshift.io/v1
    kind: ClusterVersion
    name: version
    uid: 36282574-bf9f-409e-a6cd-3032939293eb
  resourceVersion: "1865"
  uid: 0c0f7a4c-4307-4187-b591-6155695ac85b
spec:
  workerLatencyProfile: MediumUpdateAverageReaction 1

# ...

1: Specifies the medium worker latency policy.

Scheduling on each worker node is disabled as the change is being applied.

Optional: Move to the low worker latency profile:

Edit the node.config object:
```
$ oc edit nodes.config/cluster
```

Change the spec.workerLatencyProfile value to LowUpdateSlowReaction:

Example node.config object

apiVersion: config.openshift.io/v1
kind: Node
metadata:
  annotations:
    include.release.openshift.io/ibm-cloud-managed: "true"
    include.release.openshift.io/self-managed-high-availability: "true"
    include.release.openshift.io/single-node-developer: "true"
    release.openshift.io/create-only: "true"
  creationTimestamp: "2022-07-08T16:02:51Z"
  generation: 1
  name: cluster
  ownerReferences:
  - apiVersion: config.openshift.io/v1
    kind: ClusterVersion
    name: version
    uid: 36282574-bf9f-409e-a6cd-3032939293eb
  resourceVersion: "1865"
  uid: 0c0f7a4c-4307-4187-b591-6155695ac85b
spec:
  workerLatencyProfile: LowUpdateSlowReaction 1

# ...

1: Specifies use of the low worker latency policy.

Scheduling on each worker node is disabled as the change is being applied.

Verification

When all nodes return to the Ready condition, you can use the following command to look in the Kubernetes Controller Manager to ensure it was applied:

$ oc get KubeControllerManager -o yaml | grep -i workerlatency -A 5 -B 5

Example output

# ...
    - lastTransitionTime: "2022-07-11T19:47:10Z"
      reason: ProfileUpdated
      status: "False"
      type: WorkerLatencyProfileProgressing
    - lastTransitionTime: "2022-07-11T19:47:10Z" 1
      message: all static pod revision(s) have updated latency profile
      reason: ProfileUpdated
      status: "True"
      type: WorkerLatencyProfileComplete
    - lastTransitionTime: "2022-07-11T19:20:11Z"
      reason: AsExpected
      status: "False"
      type: WorkerLatencyProfileDegraded
    - lastTransitionTime: "2022-07-11T19:20:36Z"
      status: "False"
# ...

1: Specifies that the profile is applied and active.

To change the medium profile to default or change the default to medium, edit the node.config object and set the spec.workerLatencyProfile parameter to the appropriate value.

15.4. Example steps for displaying resulting values of workerLatencyProfile

You can display the values in the workerLatencyProfile with the following commands.

Verification

Check the default-not-ready-toleration-seconds and default-unreachable-toleration-seconds fields output by the Kube API Server:

$ oc get KubeAPIServer -o yaml | grep -A 1 default-

Example output

default-not-ready-toleration-seconds:
- "300"
default-unreachable-toleration-seconds:
- "300"

Check the values of the node-monitor-grace-period field from the Kube Controller Manager:
```
$ oc get KubeControllerManager -o yaml | grep -A 1 node-monitor
```
Example output
```
node-monitor-grace-period:
- 40s
```
Check the nodeStatusUpdateFrequency value from the Kubelet. Set the directory /host as the root directory within the debug shell. By changing the root directory to /host, you can run binaries contained in the host’s executable paths:
```
$ oc debug node/<worker-node-name>
$ chroot /host
# cat /etc/kubernetes/kubelet.conf|grep nodeStatusUpdateFrequency
```
Example output
```
  “nodeStatusUpdateFrequency”: “10s”
```

These outputs validate the set of timing variables for the Worker Latency Profile.

Chapter 16. Workload partitioning

In resource-constrained environments, you can use workload partitioning to isolate OpenShift Container Platform services, cluster management workloads, and infrastructure pods to run on a reserved set of CPUs.

The minimum number of reserved CPUs required for the cluster management is four CPU Hyper-Threads (HTs). With workload partitioning, you annotate the set of cluster management pods and a set of typical add-on Operators for inclusion in the cluster management workload partition. These pods operate normally within the minimum size CPU configuration. Additional Operators or workloads outside of the set of minimum cluster management pods require additional CPUs to be added to the workload partition.

Workload partitioning isolates user workloads from platform workloads using standard Kubernetes scheduling capabilities.

The following changes are required for workload partitioning:

In the install-config.yaml file, add the additional field: cpuPartitioningMode.

apiVersion: v1
baseDomain: devcluster.openshift.com
cpuPartitioningMode: AllNodes 1
compute:
  - architecture: amd64
    hyperthreading: Enabled
    name: worker
    platform: {}
    replicas: 3
controlPlane:
  architecture: amd64
  hyperthreading: Enabled
  name: master
  platform: {}
  replicas: 3

1: Sets up a cluster for CPU partitioning at install time. The default value is None.

Note

Workload partitioning can only be enabled during cluster installation. You cannot disable workload partitioning postinstallation.

In the performance profile, specify the isolated and reserved CPUs.

Recommended performance profile configuration

apiVersion: performance.openshift.io/v2
kind: PerformanceProfile
metadata:
  # if you change this name make sure the 'include' line in TunedPerformancePatch.yaml
  # matches this name: include=openshift-node-performance-${PerformanceProfile.metadata.name}
  # Also in file 'validatorCRs/informDuValidator.yaml':
  # name: 50-performance-${PerformanceProfile.metadata.name}
  name: openshift-node-performance-profile
  annotations:
    ran.openshift.io/reference-configuration: "ran-du.redhat.com"
spec:
  additionalKernelArgs:
    - "rcupdate.rcu_normal_after_boot=0"
    - "efi=runtime"
    - "vfio_pci.enable_sriov=1"
    - "vfio_pci.disable_idle_d3=1"
    - "module_blacklist=irdma"
  cpu:
    isolated: $isolated
    reserved: $reserved
  hugepages:
    defaultHugepagesSize: $defaultHugepagesSize
    pages:
      - size: $size
        count: $count
        node: $node
  machineConfigPoolSelector:
    pools.operator.machineconfiguration.openshift.io/$mcp: ""
  nodeSelector:
    node-role.kubernetes.io/$mcp: ""
  numa:
    topologyPolicy: "restricted"
  # To use the standard (non-realtime) kernel, set enabled to false
  realTimeKernel:
    enabled: true
  workloadHints:
    # WorkloadHints defines the set of upper level flags for different type of workloads.
    # See https://github.com/openshift/cluster-node-tuning-operator/blob/master/docs/performanceprofile/performance_profile.md#workloadhints
    # for detailed descriptions of each item.
    # The configuration below is set for a low latency, performance mode.
    realTime: true
    highPowerConsumption: false
    perPodPowerManagement: false

Table 16.1. PerformanceProfile CR options for single-node OpenShift clusters
PerformanceProfile CR field	Description
`metadata.name`	Ensure that `name` matches the following fields set in related GitOps ZTP custom resources (CRs): `include=openshift-node-performance-${PerformanceProfile.metadata.name}` in `TunedPerformancePatch.yaml` `name: 50-performance-${PerformanceProfile.metadata.name}` in `validatorCRs/informDuValidator.yaml`
`spec.additionalKernelArgs`	`"efi=runtime"` Configures UEFI secure boot for the cluster host.
`spec.cpu.isolated`	Set the isolated CPUs. Ensure all of the Hyper-Threading pairs match. Important The reserved and isolated CPU pools must not overlap and together must span all available cores. CPU cores that are not accounted for cause an undefined behaviour in the system.
`spec.cpu.reserved`	Set the reserved CPUs. When workload partitioning is enabled, system processes, kernel threads, and system container threads are restricted to these CPUs. All CPUs that are not isolated should be reserved.
`spec.hugepages.pages`	Set the number of huge pages (`count`) Set the huge pages size (`size`). Set `node` to the NUMA node where the `hugepages` are allocated (`node`)
`spec.realTimeKernel`	Set `enabled` to `true` to use the realtime kernel.
`spec.workloadHints`	Use `workloadHints` to define the set of top level flags for different type of workloads. The example configuration configures the cluster for low latency and high performance.

Workload partitioning introduces an extended management.workload.openshift.io/cores resource type for platform pods. kubelet advertises the resources and CPU requests by pods allocated to the pool within the corresponding resource. When workload partitioning is enabled, the management.workload.openshift.io/cores resource allows the scheduler to correctly assign pods based on the cpushares capacity of the host, not just the default cpuset.

Additional resources

For the recommended workload partitioning configuration for single-node OpenShift clusters, see Workload partitioning.

Chapter 17. Requesting CRI-O and Kubelet profiling data by using the Node Observability Operator

The Node Observability Operator collects and stores the CRI-O and Kubelet profiling data of worker nodes. You can query the profiling data to analyze the CRI-O and Kubelet performance trends and debug the performance-related issues.

Important

The Node Observability Operator is a Technology Preview feature only. Technology Preview features are not supported with Red Hat production service level agreements (SLAs) and might not be functionally complete. Red Hat does not recommend using them in production. These features provide early access to upcoming product features, enabling customers to test functionality and provide feedback during the development process.

For more information about the support scope of Red Hat Technology Preview features, see Technology Preview Features Support Scope.

17.1. Workflow of the Node Observability Operator

The following workflow outlines on how to query the profiling data using the Node Observability Operator:

Install the Node Observability Operator in the OpenShift Container Platform cluster.
Create a NodeObservability custom resource to enable the CRI-O profiling on the worker nodes of your choice.
Run the profiling query to generate the profiling data.

17.2. Installing the Node Observability Operator

The Node Observability Operator is not installed in OpenShift Container Platform by default. You can install the Node Observability Operator by using the OpenShift Container Platform CLI or the web console.

17.2.1. Installing the Node Observability Operator using the CLI

You can install the Node Observability Operator by using the OpenShift CLI (oc).

Prerequisites

You have installed the OpenShift CLI (oc).
You have access to the cluster with cluster-admin privileges.

Procedure

Confirm that the Node Observability Operator is available by running the following command:

$ oc get packagemanifests -n openshift-marketplace node-observability-operator

Example output

NAME                            CATALOG                AGE
node-observability-operator     Red Hat Operators      9h

Create the node-observability-operator namespace by running the following command:
```
$ oc new-project node-observability-operator
```

Create an OperatorGroup object YAML file:

cat <<EOF | oc apply -f -
apiVersion: operators.coreos.com/v1
kind: OperatorGroup
metadata:
  name: node-observability-operator
  namespace: node-observability-operator
spec:
  targetNamespaces: []
EOF

Create a Subscription object YAML file to subscribe a namespace to an Operator:

cat <<EOF | oc apply -f -
apiVersion: operators.coreos.com/v1alpha1
kind: Subscription
metadata:
  name: node-observability-operator
  namespace: node-observability-operator
spec:
  channel: alpha
  name: node-observability-operator
  source: redhat-operators
  sourceNamespace: openshift-marketplace
EOF

Verification

View the install plan name by running the following command:

$ oc -n node-observability-operator get sub node-observability-operator -o yaml | yq '.status.installplan.name'

Example output

install-dt54w

Verify the install plan status by running the following command:
```
$ oc -n node-observability-operator get ip <install_plan_name> -o yaml | yq '.status.phase'
```
<install_plan_name> is the install plan name that you obtained from the output of the previous command.
Example output
```
COMPLETE
```

Verify that the Node Observability Operator is up and running:

$ oc get deploy -n node-observability-operator

Example output

NAME                                            READY   UP-TO-DATE  AVAILABLE   AGE
node-observability-operator-controller-manager  1/1     1           1           40h

17.2.2. Installing the Node Observability Operator using the web console

You can install the Node Observability Operator from the OpenShift Container Platform web console.

Prerequisites

You have access to the cluster with cluster-admin privileges.
You have access to the OpenShift Container Platform web console.

Procedure

Log in to the OpenShift Container Platform web console.
In the Administrator’s navigation panel, expand Operators → OperatorHub.
In the All items field, enter Node Observability Operator and select the Node Observability Operator tile.
Click Install.
On the Install Operator page, configure the following settings:
1. In the Update channel area, click alpha.
2. In the Installation mode area, click A specific namespace on the cluster.
3. From the Installed Namespace list, select node-observability-operator from the list.
4. In the Update approval area, select Automatic.
5. Click Install.

Verification

In the Administrator’s navigation panel, expand Operators → Installed Operators.
Verify that the Node Observability Operator is listed in the Operators list.

17.3. Creating the Node Observability custom resource

You must create and run the NodeObservability custom resource (CR) before you run the profiling query. When you run the NodeObservability CR, it creates the necessary machine config and machine config pool CRs to enable the CRI-O profiling on the worker nodes matching the nodeSelector.

Important

If CRI-O profiling is not enabled on the worker nodes, the NodeObservabilityMachineConfig resource gets created. Worker nodes matching the nodeSelector specified in NodeObservability CR restarts. This might take 10 or more minutes to complete.

Note

Kubelet profiling is enabled by default.

The CRI-O unix socket of the node is mounted on the agent pod, which allows the agent to communicate with CRI-O to run the pprof request. Similarly, the kubelet-serving-ca certificate chain is mounted on the agent pod, which allows secure communication between the agent and node’s kubelet endpoint.

Prerequisites

You have installed the Node Observability Operator.
You have installed the OpenShift CLI (oc).
You have access to the cluster with cluster-admin privileges.

Procedure

Log in to the OpenShift Container Platform CLI by running the following command:
```
$ oc login -u kubeadmin https://<HOSTNAME>:6443
```
Switch back to the node-observability-operator namespace by running the following command:
```
$ oc project node-observability-operator
```
Create a CR file named nodeobservability.yaml that contains the following text:
```
    apiVersion: nodeobservability.olm.openshift.io/v1alpha2
    kind: NodeObservability
    metadata:
      name: cluster 1
    spec:
      nodeSelector:
        kubernetes.io/hostname: <node_hostname> 2
      type: crio-kubelet
```
1
You must specify the name as cluster because there should be only one NodeObservability CR per cluster.
2
Specify the nodes on which the Node Observability agent must be deployed.

Run the NodeObservability CR:

oc apply -f nodeobservability.yaml

Example output

nodeobservability.olm.openshift.io/cluster created

Review the status of the NodeObservability CR by running the following command:

$ oc get nob/cluster -o yaml | yq '.status.conditions'

Example output

conditions:
  conditions:
  - lastTransitionTime: "2022-07-05T07:33:54Z"
    message: 'DaemonSet node-observability-ds ready: true NodeObservabilityMachineConfig
      ready: true'
    reason: Ready
    status: "True"
    type: Ready

NodeObservability CR run is completed when the reason is Ready and the status is True.

17.4. Running the profiling query

To run the profiling query, you must create a NodeObservabilityRun resource. The profiling query is a blocking operation that fetches CRI-O and Kubelet profiling data for a duration of 30 seconds. After the profiling query is complete, you must retrieve the profiling data inside the container file system /run/node-observability directory. The lifetime of data is bound to the agent pod through the emptyDir volume, so you can access the profiling data while the agent pod is in the running status.

Important

You can request only one profiling query at any point of time.

Prerequisites

You have installed the Node Observability Operator.
You have created the NodeObservability custom resource (CR).
You have access to the cluster with cluster-admin privileges.

Procedure

Create a NodeObservabilityRun resource file named nodeobservabilityrun.yaml that contains the following text:

apiVersion: nodeobservability.olm.openshift.io/v1alpha2
kind: NodeObservabilityRun
metadata:
  name: nodeobservabilityrun
spec:
  nodeObservabilityRef:
    name: cluster

Trigger the profiling query by running the NodeObservabilityRun resource:
```
$ oc apply -f nodeobservabilityrun.yaml
```

Review the status of the NodeObservabilityRun by running the following command:

$ oc get nodeobservabilityrun nodeobservabilityrun -o yaml  | yq '.status.conditions'

Example output

conditions:
- lastTransitionTime: "2022-07-07T14:57:34Z"
  message: Ready to start profiling
  reason: Ready
  status: "True"
  type: Ready
- lastTransitionTime: "2022-07-07T14:58:10Z"
  message: Profiling query done
  reason: Finished
  status: "True"
  type: Finished

The profiling query is complete once the status is True and type is Finished.

Retrieve the profiling data from the container’s /run/node-observability path by running the following bash script:

for a in $(oc get nodeobservabilityrun nodeobservabilityrun -o yaml | yq .status.agents[].name); do
  echo "agent ${a}"
  mkdir -p "/tmp/${a}"
  for p in $(oc exec "${a}" -c node-observability-agent -- bash -c "ls /run/node-observability/*.pprof"); do
    f="$(basename ${p})"
    echo "copying ${f} to /tmp/${a}/${f}"
    oc exec "${a}" -c node-observability-agent -- cat "${p}" > "/tmp/${a}/${f}"
  done
done

Chapter 18. Clusters at the network far edge

18.1. Challenges of the network far edge

Edge computing presents complex challenges when managing many sites in geographically displaced locations. Use GitOps Zero Touch Provisioning (ZTP) to provision and manage sites at the far edge of the network.

18.1.1. Overcoming the challenges of the network far edge

Today, service providers want to deploy their infrastructure at the edge of the network. This presents significant challenges:

How do you handle deployments of many edge sites in parallel?
What happens when you need to deploy sites in disconnected environments?
How do you manage the lifecycle of large fleets of clusters?

GitOps Zero Touch Provisioning (ZTP) and GitOps meets these challenges by allowing you to provision remote edge sites at scale with declarative site definitions and configurations for bare-metal equipment. Template or overlay configurations install OpenShift Container Platform features that are required for CNF workloads. The full lifecycle of installation and upgrades is handled through the GitOps ZTP pipeline.

GitOps ZTP uses GitOps for infrastructure deployments. With GitOps, you use declarative YAML files and other defined patterns stored in Git repositories. Red Hat Advanced Cluster Management (RHACM) uses your Git repositories to drive the deployment of your infrastructure.

GitOps provides traceability, role-based access control (RBAC), and a single source of truth for the desired state of each site. Scalability issues are addressed by Git methodologies and event driven operations through webhooks.

You start the GitOps ZTP workflow by creating declarative site definition and configuration custom resources (CRs) that the GitOps ZTP pipeline delivers to the edge nodes.

The following diagram shows how GitOps ZTP works within the far edge framework.

18.1.2. Using GitOps ZTP to provision clusters at the network far edge

Red Hat Advanced Cluster Management (RHACM) manages clusters in a hub-and-spoke architecture, where a single hub cluster manages many spoke clusters. Hub clusters running RHACM provision and deploy the managed clusters by using GitOps Zero Touch Provisioning (ZTP) and the assisted service that is deployed when you install RHACM.

The assisted service handles provisioning of OpenShift Container Platform on single node clusters, three-node clusters, or standard clusters running on bare metal.

A high-level overview of using GitOps ZTP to provision and maintain bare-metal hosts with OpenShift Container Platform is as follows:

A hub cluster running RHACM manages an OpenShift image registry that mirrors the OpenShift Container Platform release images. RHACM uses the OpenShift image registry to provision the managed clusters.
You manage the bare-metal hosts in a YAML format inventory file, versioned in a Git repository.
You make the hosts ready for provisioning as managed clusters, and use RHACM and the assisted service to install the bare-metal hosts on site.

Installing and deploying the clusters is a two-stage process, involving an initial installation phase, and a subsequent configuration and deployment phase. The following diagram illustrates this workflow:

Using GitOps and GitOps ZTP to install and deploy managed clusters

18.1.3. Installing managed clusters with SiteConfig resources and RHACM

GitOps Zero Touch Provisioning (ZTP) uses SiteConfig custom resources (CRs) in a Git repository to manage the processes that install OpenShift Container Platform clusters. The SiteConfig CR contains cluster-specific parameters required for installation. It has options for applying select configuration CRs during installation including user defined extra manifests.

The GitOps ZTP plugin processes SiteConfig CRs to generate a collection of CRs on the hub cluster. This triggers the assisted service in Red Hat Advanced Cluster Management (RHACM) to install OpenShift Container Platform on the bare-metal host. You can find installation status and error messages in these CRs on the hub cluster.

You can provision single clusters manually or in batches with GitOps ZTP:

Provisioning a single cluster: Create a single SiteConfig CR and related installation and configuration CRs for the cluster, and apply them in the hub cluster to begin cluster provisioning. This is a good way to test your CRs before deploying on a larger scale.
Provisioning many clusters: Install managed clusters in batches of up to 400 by defining SiteConfig and related CRs in a Git repository. ArgoCD uses the SiteConfig CRs to deploy the sites. The RHACM policy generator creates the manifests and applies them to the hub cluster. This starts the cluster provisioning process.

18.1.4. Configuring managed clusters with policies and PolicyGenTemplate resources

GitOps Zero Touch Provisioning (ZTP) uses Red Hat Advanced Cluster Management (RHACM) to configure clusters by using a policy-based governance approach to applying the configuration.

The policy generator or PolicyGen is a plugin for the GitOps Operator that enables the creation of RHACM policies from a concise template. The tool can combine multiple CRs into a single policy, and you can generate multiple policies that apply to various subsets of clusters in your fleet.

Note

For scalability and to reduce the complexity of managing configurations across the fleet of clusters, use configuration CRs with as much commonality as possible.

Where possible, apply configuration CRs using a fleet-wide common policy.
The next preference is to create logical groupings of clusters to manage as much of the remaining configurations as possible under a group policy.
When a configuration is unique to an individual site, use RHACM templating on the hub cluster to inject the site-specific data into a common or group policy. Alternatively, apply an individual site policy for the site.

The following diagram shows how the policy generator interacts with GitOps and RHACM in the configuration phase of cluster deployment.

For large fleets of clusters, it is typical for there to be a high-level of consistency in the configuration of those clusters.

The following recommended structuring of policies combines configuration CRs to meet several goals:

Describe common configurations once and apply to the fleet.
Minimize the number of maintained and managed policies.
Support flexibility in common configurations for cluster variants.

Table 18.1. Recommended PolicyGenTemplate policy categories
Policy category	Description
Common	A policy that exists in the common category is applied to all clusters in the fleet. Use common `PolicyGenTemplate` CRs to apply common installation settings across all cluster types.
Groups	A policy that exists in the groups category is applied to a group of clusters in the fleet. Use group `PolicyGenTemplate` CRs to manage specific aspects of single-node, three-node, and standard cluster installations. Cluster groups can also follow geographic region, hardware variant, etc.
Sites	A policy that exists in the sites category is applied to a specific cluster site. Any cluster can have its own specific policies maintained.

Additional resources

For more information about extracting the reference SiteConfig and PolicyGenTemplate CRs from the ztp-site-generate container image, see Preparing the ZTP Git repository.

18.2. Preparing the hub cluster for ZTP

To use RHACM in a disconnected environment, create a mirror registry that mirrors the OpenShift Container Platform release images and Operator Lifecycle Manager (OLM) catalog that contains the required Operator images. OLM manages, installs, and upgrades Operators and their dependencies in the cluster. You can also use a disconnected mirror host to serve the RHCOS ISO and RootFS disk images that are used to provision the bare-metal hosts.

18.2.1. Telco RAN DU 4.14 validated software components

The Red Hat telco RAN DU 4.14 solution has been validated using the following Red Hat software products for OpenShift Container Platform managed clusters and hub clusters.

Table 18.2. Telco RAN DU managed cluster validated software components
Component	Software version
Managed cluster version	4.14
Cluster Logging Operator	5.7
Local Storage Operator	4.14
PTP Operator	4.14
SRIOV Operator	4.14
Node Tuning Operator	4.14
Logging Operator	4.14
SRIOV-FEC Operator	2.7

Table 18.3. Hub cluster validated software components
Component	Software version
Hub cluster version	4.14
GitOps ZTP plugin	4.14
Red Hat Advanced Cluster Management (RHACM)	2.9, 2.10
Red Hat OpenShift GitOps	1.9, 1.10
Topology Aware Lifecycle Manager (TALM)	4.14

18.2.2. Recommended hub cluster specifications and managed cluster limits for GitOps ZTP

With GitOps Zero Touch Provisioning (ZTP), you can manage thousands of clusters in geographically dispersed regions and networks. The Red Hat Performance and Scale lab successfully created and managed 3500 virtual single-node OpenShift clusters with a reduced DU profile from a single Red Hat Advanced Cluster Management (RHACM) hub cluster in a lab environment.

In real-world situations, the scaling limits for the number of clusters that you can manage will vary depending on various factors affecting the hub cluster. For example:

Hub cluster resources: Available hub cluster host resources (CPU, memory, storage) are an important factor in determining how many clusters the hub cluster can manage. The more resources allocated to the hub cluster, the more managed clusters it can accommodate.
Hub cluster storage: The hub cluster host storage IOPS rating and whether the hub cluster hosts use NVMe storage can affect hub cluster performance and the number of clusters it can manage.
Network bandwidth and latency: Slow or high-latency network connections between the hub cluster and managed clusters can impact how the hub cluster manages multiple clusters.
Managed cluster size and complexity: The size and complexity of the managed clusters also affects the capacity of the hub cluster. Larger managed clusters with more nodes, namespaces, and resources require additional processing and management resources. Similarly, clusters with complex configurations such as the RAN DU profile or diverse workloads can require more resources from the hub cluster.
Number of managed policies: The number of policies managed by the hub cluster scaled over the number of managed clusters bound to those policies is an important factor that determines how many clusters can be managed.
Monitoring and management workloads: RHACM continuously monitors and manages the managed clusters. The number and complexity of monitoring and management workloads running on the hub cluster can affect its capacity. Intensive monitoring or frequent reconciliation operations can require additional resources, potentially limiting the number of manageable clusters.
RHACM version and configuration: Different versions of RHACM can have varying performance characteristics and resource requirements. Additionally, the configuration settings of RHACM, such as the number of concurrent reconciliations or the frequency of health checks, can affect the managed cluster capacity of the hub cluster.

Use the following representative configuration and network specifications to develop your own Hub cluster and network specifications.

Important

The following guidelines are based on internal lab benchmark testing only and do not represent complete bare-metal host specifications.

Table 18.4. Representative three-node hub cluster machine specifications
Requirement	Description
OpenShift Container Platform	version 4.13
RHACM	version 2.7
Topology Aware Lifecycle Manager (TALM)	version 4.13
Server hardware	3 x Dell PowerEdge R650 rack servers
NVMe hard disks	50 GB disk for `/var/lib/etcd` 2.9 TB disk for `/var/lib/containers`
SSD hard disks	1 SSD split into 15 200GB thin-provisioned logical volumes provisioned as `PV` CRs 1 SSD serving as an extra large `PV` resource
Number of applied DU profile policies	5

Important

The following network specifications are representative of a typical real-world RAN network and were applied to the scale lab environment during testing.

Table 18.5. Simulated lab environment network specifications
Specification	Description
Round-trip time (RTT) latency	50 ms
Packet loss	0.02% packet loss
Network bandwidth limit	20 Mbps

Additional resources

Creating and managing single-node OpenShift clusters with RHACM

18.2.3. Installing GitOps ZTP in a disconnected environment

Use Red Hat Advanced Cluster Management (RHACM), Red Hat OpenShift GitOps, and Topology Aware Lifecycle Manager (TALM) on the hub cluster in the disconnected environment to manage the deployment of multiple managed clusters.

Prerequisites

You have installed the OpenShift Container Platform CLI (oc).
You have logged in as a user with cluster-admin privileges.
You have configured a disconnected mirror registry for use in the cluster.
Note
The disconnected mirror registry that you create must contain a version of TALM backup and pre-cache images that matches the version of TALM running in the hub cluster. The spoke cluster must be able to resolve these images in the disconnected mirror registry.

Procedure

Install RHACM in the hub cluster. See Installing RHACM in a disconnected environment.
Install GitOps and TALM in the hub cluster.

Additional resources

18.2.4. Adding RHCOS ISO and RootFS images to the disconnected mirror host

Before you begin installing clusters in the disconnected environment with Red Hat Advanced Cluster Management (RHACM), you must first host Red Hat Enterprise Linux CoreOS (RHCOS) images for it to use. Use a disconnected mirror to host the RHCOS images.

Prerequisites

Deploy and configure an HTTP server to host the RHCOS image resources on the network. You must be able to access the HTTP server from your computer, and from the machines that you create.

Important

The RHCOS images might not change with every release of OpenShift Container Platform. You must download images with the highest version that is less than or equal to the version that you install. Use the image versions that match your OpenShift Container Platform version if they are available. You require ISO and RootFS images to install RHCOS on the hosts. RHCOS QCOW2 images are not supported for this installation type.

Procedure

Obtain the RHCOS ISO and RootFS images from mirror.openshift.com, for example:

Export the required image names and OpenShift Container Platform version as environment variables:
```
$ export ISO_IMAGE_NAME=<iso_image_name> 1
```
```
$ export ROOTFS_IMAGE_NAME=<rootfs_image_name> 1
```
```
$ export OCP_VERSION=<ocp_version> 1
```
1
ISO image name, for example, rhcos-4.14.1-x86_64-live.x86_64.iso
1
RootFS image name, for example, rhcos-4.14.1-x86_64-live-rootfs.x86_64.img
1
OpenShift Container Platform version, for example, 4.14.1

Download the required images:

$ sudo wget https://mirror.openshift.com/pub/openshift-v4/dependencies/rhcos/4.14/${OCP_VERSION}/${ISO_IMAGE_NAME} -O /var/www/html/${ISO_IMAGE_NAME}

$ sudo wget https://mirror.openshift.com/pub/openshift-v4/dependencies/rhcos/4.14/${OCP_VERSION}/${ROOTFS_IMAGE_NAME} -O /var/www/html/${ROOTFS_IMAGE_NAME}

Verification steps

Verify that the images downloaded successfully and are being served on the disconnected mirror host, for example:

$ wget http://$(hostname)/${ISO_IMAGE_NAME}

Example output

Saving to: rhcos-4.14.1-x86_64-live.x86_64.iso
rhcos-4.14.1-x86_64-live.x86_64.iso-  11%[====>    ]  10.01M  4.71MB/s

Additional resources

18.2.5. Enabling the assisted service

Red Hat Advanced Cluster Management (RHACM) uses the assisted service to deploy OpenShift Container Platform clusters. The assisted service is deployed automatically when you enable the MultiClusterHub Operator on Red Hat Advanced Cluster Management (RHACM). After that, you need to configure the Provisioning resource to watch all namespaces and to update the AgentServiceConfig custom resource (CR) with references to the ISO and RootFS images that are hosted on the mirror registry HTTP server.

Prerequisites

You have installed the OpenShift CLI (oc).
You have logged in to the hub cluster as a user with cluster-admin privileges.
You have RHACM with MultiClusterHub enabled.

Procedure

Enable the Provisioning resource to watch all namespaces and configure mirrors for disconnected environments. For more information, see Enabling the central infrastructure management service.
Update the AgentServiceConfig CR by running the following command:
```
$ oc edit AgentServiceConfig
```
Add the following entry to the items.spec.osImages field in the CR:
```
- cpuArchitecture: x86_64
    openshiftVersion: "4.14"
    rootFSUrl: https://<host>/<path>/rhcos-live-rootfs.x86_64.img
    url: https://<host>/<path>/rhcos-live.x86_64.iso
```
where:
<host>
Is the fully qualified domain name (FQDN) for the target mirror registry HTTP server.
<path>
Is the path to the image on the target mirror registry.
Save and quit the editor to apply the changes.

18.2.6. Configuring the hub cluster to use a disconnected mirror registry

You can configure the hub cluster to use a disconnected mirror registry for a disconnected environment.

Prerequisites

You have a disconnected hub cluster installation with Red Hat Advanced Cluster Management (RHACM) 2.8 installed.
You have hosted the rootfs and iso images on an HTTP server. See the Additional resources section for guidance about Mirroring the OpenShift Container Platform image repository.

Warning

If you enable TLS for the HTTP server, you must confirm the root certificate is signed by an authority trusted by the client and verify the trusted certificate chain between your OpenShift Container Platform hub and managed clusters and the HTTP server. Using a server configured with an untrusted certificate prevents the images from being downloaded to the image creation service. Using untrusted HTTPS servers is not supported.

Procedure

Create a ConfigMap containing the mirror registry config:
```
apiVersion: v1
kind: ConfigMap
metadata:
  name: assisted-installer-mirror-config
  namespace: multicluster-engine 1
  labels:
    app: assisted-service
data:
  ca-bundle.crt: | 2
    -----BEGIN CERTIFICATE-----
    <certificate_contents>
    -----END CERTIFICATE-----

  registries.conf: | 3
    unqualified-search-registries = ["registry.access.redhat.com", "docker.io"]

    [[registry]]
       prefix = ""
       location = "quay.io/example-repository" 4
       mirror-by-digest-only = true

       [[registry.mirror]]
       location = "mirror1.registry.corp.com:5000/example-repository" 5
```
1
The ConfigMap namespace must be set to multicluster-engine.
2
The mirror registry’s certificate that is used when creating the mirror registry.
3
The configuration file for the mirror registry. The mirror registry configuration adds mirror information to the /etc/containers/registries.conf file in the discovery image. The mirror information is stored in the imageContentSources section of the install-config.yaml file when the information is passed to the installation program. The Assisted Service pod that runs on the hub cluster fetches the container images from the configured mirror registry.
4
The URL of the mirror registry. You must use the URL from the imageContentSources section by running the oc adm release mirror command when you configure the mirror registry. For more information, see the Mirroring the OpenShift Container Platform image repository section.
5
The registries defined in the registries.conf file must be scoped by repository, not by registry. In this example, both the quay.io/example-repository and the mirror1.registry.corp.com:5000/example-repository repositories are scoped by the example-repository repository.
This updates mirrorRegistryRef in the AgentServiceConfig custom resource, as shown below:
Example output
```
apiVersion: agent-install.openshift.io/v1beta1
kind: AgentServiceConfig
metadata:
  name: agent
  namespace: multicluster-engine 1
spec:
  databaseStorage:
    volumeName: <db_pv_name>
    accessModes:
    - ReadWriteOnce
    resources:
      requests:
        storage: <db_storage_size>
  filesystemStorage:
    volumeName: <fs_pv_name>
    accessModes:
    - ReadWriteOnce
    resources:
      requests:
        storage: <fs_storage_size>
  mirrorRegistryRef:
    name: assisted-installer-mirror-config 2
  osImages:
    - openshiftVersion: <ocp_version>
      url: <iso_url> 3
```
1
Set the AgentServiceConfig namespace to multicluster-engine to match the ConfigMap namespace
2
Set mirrorRegistryRef.name to match the definition specified in the related ConfigMap CR
3
Set the URL for the ISO hosted on the httpd server

Important

A valid NTP server is required during cluster installation. Ensure that a suitable NTP server is available and can be reached from the installed clusters through the disconnected network.

Additional resources

Mirroring the OpenShift Container Platform image repository

18.2.7. Configuring the hub cluster to use unauthenticated registries

You can configure the hub cluster to use unauthenticated registries. Unauthenticated registries does not require authentication to access and download images.

Prerequisites

You have installed and configured a hub cluster and installed Red Hat Advanced Cluster Management (RHACM) on the hub cluster.
You have installed the OpenShift Container Platform CLI (oc).
You have logged in as a user with cluster-admin privileges.
You have configured an unauthenticated registry for use with the hub cluster.

Procedure

Update the AgentServiceConfig custom resource (CR) by running the following command:
```
$ oc edit AgentServiceConfig agent
```
Add the unauthenticatedRegistries field in the CR:
```
apiVersion: agent-install.openshift.io/v1beta1
kind: AgentServiceConfig
metadata:
  name: agent
spec:
  unauthenticatedRegistries:
  - example.registry.com
  - example.registry2.com
  ...
```
Unauthenticated registries are listed under spec.unauthenticatedRegistries in the AgentServiceConfig resource. Any registry on this list is not required to have an entry in the pull secret used for the spoke cluster installation. assisted-service validates the pull secret by making sure it contains the authentication information for every image registry used for installation.

Note

Mirror registries are automatically added to the ignore list and do not need to be added under spec.unauthenticatedRegistries. Specifying the PUBLIC_CONTAINER_REGISTRIES environment variable in the ConfigMap overrides the default values with the specified value. The PUBLIC_CONTAINER_REGISTRIES defaults are quay.io and registry.svc.ci.openshift.org.

Verification

Verify that you can access the newly added registry from the hub cluster by running the following commands:

Open a debug shell prompt to the hub cluster:
```
$ oc debug node/<node_name>
```
Test access to the unauthenticated registry by running the following command:
```
sh-4.4# podman login -u kubeadmin -p $(oc whoami -t) <unauthenticated_registry>
```
where:
<unauthenticated_registry>
Is the new registry, for example, unauthenticated-image-registry.openshift-image-registry.svc:5000.
Example output
```
Login Succeeded!
```

18.2.8. Configuring the hub cluster with ArgoCD

You can configure the hub cluster with a set of ArgoCD applications that generate the required installation and policy custom resources (CRs) for each site with GitOps Zero Touch Provisioning (ZTP).

Note

Red Hat Advanced Cluster Management (RHACM) uses SiteConfig CRs to generate the Day 1 managed cluster installation CRs for ArgoCD. Each ArgoCD application can manage a maximum of 300 SiteConfig CRs.

Prerequisites

You have a OpenShift Container Platform hub cluster with Red Hat Advanced Cluster Management (RHACM) and Red Hat OpenShift GitOps installed.
You have extracted the reference deployment from the GitOps ZTP plugin container as described in the "Preparing the GitOps ZTP site configuration repository" section. Extracting the reference deployment creates the out/argocd/deployment directory referenced in the following procedure.

Procedure

Prepare the ArgoCD pipeline configuration:
1. Create a Git repository with the directory structure similar to the example directory. For more information, see "Preparing the GitOps ZTP site configuration repository".
2. Configure access to the repository using the ArgoCD UI. Under Settings configure the following:
  - Repositories - Add the connection information. The URL must end in .git, for example, https://repo.example.com/repo.git and credentials.
  - Certificates - Add the public certificate for the repository, if needed.
3. Modify the two ArgoCD applications, out/argocd/deployment/clusters-app.yaml and out/argocd/deployment/policies-app.yaml, based on your Git repository:
  - Update the URL to point to the Git repository. The URL ends with .git, for example, https://repo.example.com/repo.git.
  - The targetRevision indicates which Git repository branch to monitor.
  - path specifies the path to the SiteConfig and PolicyGenTemplate CRs, respectively.

To install the GitOps ZTP plugin, patch the ArgoCD instance in the hub cluster with the relevant multicluster engine (MCE) subscription image. Customize the patch file that you previously extracted into the out/argocd/deployment/ directory for your environment.

Select the multicluster-operators-subscription image that matches your RHACM version.

Table 18.6. multicluster-operators-subscription image versions
OpenShift Container Platform version	RHACM version	MCE version	MCE RHEL version	MCE image
4.14, 4.15, 4.16	2.8, 2.9	2.8, 2.9	RHEL 8	`registry.redhat.io/rhacm2/multicluster-operators-subscription-rhel8:v2.8` `registry.redhat.io/rhacm2/multicluster-operators-subscription-rhel8:v2.9`
4.14, 4.15, 4.16	2.10	2.10	RHEL 9	`registry.redhat.io/rhacm2/multicluster-operators-subscription-rhel9:v2.10`

Important

The version of the multicluster-operators-subscription image should match the RHACM version. Beginning with the MCE 2.10 release, RHEL 9 is the base image for multicluster-operators-subscription images.

Add the following configuration to the out/argocd/deployment/argocd-openshift-gitops-patch.json file:

{
  "args": [
    "-c",
    "mkdir -p /.config/kustomize/plugin/policy.open-cluster-management.io/v1/policygenerator && cp /policy-generator/PolicyGenerator-not-fips-compliant /.config/kustomize/plugin/policy.open-cluster-management.io/v1/policygenerator/PolicyGenerator" 1
  ],
  "command": [
    "/bin/bash"
  ],
  "image": "registry.redhat.io/rhacm2/multicluster-operators-subscription-rhel9:v2.10", 2 3
  "name": "policy-generator-install",
  "imagePullPolicy": "Always",
  "volumeMounts": [
    {
      "mountPath": "/.config",
      "name": "kustomize"
    }
  ]
}

1: Optional: For RHEL 9 images, copy the required universal executable in the /policy-generator/PolicyGenerator-not-fips-compliant folder for the ArgoCD version.
2: Match the multicluster-operators-subscription image to the RHACM version.
3: In disconnected environments, replace the URL for the multicluster-operators-subscription image with the disconnected registry equivalent for your environment.

Patch the ArgoCD instance. Run the following command:

$ oc patch argocd openshift-gitops \
-n openshift-gitops --type=merge \
--patch-file out/argocd/deployment/argocd-openshift-gitops-patch.json

In RHACM 2.7 and later, the multicluster engine enables the cluster-proxy-addon feature by default. Apply the following patch to disable the cluster-proxy-addon feature and remove the relevant hub cluster and managed pods that are responsible for this add-on. Run the following command:
```
$ oc patch multiclusterengines.multicluster.openshift.io multiclusterengine --type=merge --patch-file out/argocd/deployment/disable-cluster-proxy-addon.json
```
Apply the pipeline configuration to your hub cluster by running the following command:
```
$ oc apply -k out/argocd/deployment
```

18.2.9. Preparing the GitOps ZTP site configuration repository

Before you can use the GitOps Zero Touch Provisioning (ZTP) pipeline, you need to prepare the Git repository to host the site configuration data.

Prerequisites

You have configured the hub cluster GitOps applications for generating the required installation and policy custom resources (CRs).
You have deployed the managed clusters using GitOps ZTP.

Procedure

Create a directory structure with separate paths for the SiteConfig and PolicyGenTemplate CRs.
Note
Keep SiteConfig and PolicyGenTemplate CRs in separate directories. Both the SiteConfig and PolicyGenTemplate directories must contain a kustomization.yaml file that explicitly includes the files in that directory.

Export the argocd directory from the ztp-site-generate container image using the following commands:

$ podman pull registry.redhat.io/openshift4/ztp-site-generate-rhel8:v4.14

$ mkdir -p ./out

$ podman run --log-driver=none --rm registry.redhat.io/openshift4/ztp-site-generate-rhel8:v4.14 extract /home/ztp --tar | tar x -C ./out

Check that the out directory contains the following subdirectories:
- out/extra-manifest contains the source CR files that SiteConfig uses to generate extra manifest configMap.
- out/source-crs contains the source CR files that PolicyGenTemplate uses to generate the Red Hat Advanced Cluster Management (RHACM) policies.
- out/argocd/deployment contains patches and YAML files to apply on the hub cluster for use in the next step of this procedure.
- out/argocd/example contains the examples for SiteConfig and PolicyGenTemplate files that represent the recommended configuration.
Copy the out/source-crs folder and contents to the PolicyGentemplate directory.
The out/extra-manifests directory contains the reference manifests for a RAN DU cluster. Copy the out/extra-manifests directory into the SiteConfig folder. This directory should contain CRs from the ztp-site-generate container only. Do not add user-provided CRs here. If you want to work with user-provided CRs you must create another directory for that content. For example:
```
example/
  ├── policygentemplates
  │   ├── kustomization.yaml
  │   └── source-crs/
  └── siteconfig
        ├── extra-manifests
        └── kustomization.yaml
```
Commit the directory structure and the kustomization.yaml files and push to your Git repository. The initial push to Git should include the kustomization.yaml files.

You can use the directory structure under out/argocd/example as a reference for the structure and content of your Git repository. That structure includes SiteConfig and PolicyGenTemplate reference CRs for single-node, three-node, and standard clusters. Remove references to cluster types that you are not using.

For all cluster types, you must:

Add the source-crs subdirectory to the policygentemplate directory.
Add the extra-manifests directory to the siteconfig directory.

The following example describes a set of CRs for a network of single-node clusters:

example/
  ├── policygentemplates
  │   ├── common-ranGen.yaml
  │   ├── example-sno-site.yaml
  │   ├── group-du-sno-ranGen.yaml
  │   ├── group-du-sno-validator-ranGen.yaml
  │   ├── kustomization.yaml
  │   ├── source-crs/
  │   └── ns.yaml
  └── siteconfig
        ├── example-sno.yaml
        ├── extra-manifests/ 1
        ├── custom-manifests/ 2
        ├── KlusterletAddonConfigOverride.yaml
        └── kustomization.yaml

1: Contains reference manifests from the ztp-container.
2: Contains custom manifests.

18.2.9.1. Preparing the GitOps ZTP site configuration repository for version independence

You can use GitOps ZTP to manage source custom resources (CRs) for managed clusters that are running different versions of OpenShift Container Platform. This means that the version of OpenShift Container Platform running on the hub cluster can be independent of the version running on the managed clusters.

Procedure

Create a directory structure with separate paths for the SiteConfig and PolicyGenTemplate CRs.
Within the PolicyGenTemplate directory, create a directory for each OpenShift Container Platform version you want to make available. For each version, create the following resources:
- kustomization.yaml file that explicitly includes the files in that directory
- source-crs directory to contain reference CR configuration files from the ztp-site-generate container
  If you want to work with user-provided CRs, you must create a separate directory for them.
In the /siteconfig directory, create a subdirectory for each OpenShift Container Platform version you want to make available. For each version, create at least one directory for reference CRs to be copied from the container. There is no restriction on the naming of directories or on the number of reference directories. If you want to work with custom manifests, you must create a separate directory for them.
The following example describes a structure using user-provided manifests and CRs for different versions of OpenShift Container Platform:
```
├── policygentemplates
│   ├── kustomization.yaml 1
│   ├── version_4.13 2
│   │   ├── common-ranGen.yaml
│   │   ├── group-du-sno-ranGen.yaml
│   │   ├── group-du-sno-validator-ranGen.yaml
│   │   ├── helix56-v413.yaml
│   │   ├── kustomization.yaml 3
│   │   ├── ns.yaml
│   │   └── source-crs/ 4
│   │      └── reference-crs/ 5
│   │      └── custom-crs/ 6
│   └── version_4.14 7
│       ├── common-ranGen.yaml
│       ├── group-du-sno-ranGen.yaml
│       ├── group-du-sno-validator-ranGen.yaml
│       ├── helix56-v414.yaml
│       ├── kustomization.yaml 8
│       ├── ns.yaml
│       └── source-crs/ 9
│         └── reference-crs/ 10
│         └── custom-crs/ 11
└── siteconfig
    ├── kustomization.yaml
    ├── version_4.13
    │   ├── helix56-v413.yaml
    │   ├── kustomization.yaml
    │   ├── extra-manifest/ 12
    │   └── custom-manifest/ 13
    └── version_4.14
        ├── helix57-v414.yaml
        ├── kustomization.yaml
        ├── extra-manifest/ 14
        └── custom-manifest/ 15
```
1
Create a top-level kustomization YAML file.
2 7
Create the version-specific directories within the custom /policygentemplates directory.
3 8
Create a kustomization.yaml file for each version.
4 9
Create a source-crs directory for each version to contain reference CRs from the ztp-site-generate container.
5 10
Create the reference-crs directory for policy CRs that are extracted from the ZTP container.
6 11
Optional: Create a custom-crs directory for user-provided CRs.
12 14
Create a directory within the custom /siteconfig directory to contain extra manifests from the ztp-site-generate container.
13 15
Create a folder to hold user-provided manifests.
Note
In the previous example, each version subdirectory in the custom /siteconfig directory contains two further subdirectories, one containing the reference manifests copied from the container, the other for custom manifests that you provide. The names assigned to those directories are examples. If you use user-provided CRs, the last directory listed under extraManifests.searchPaths in the SiteConfig CR must be the directory containing user-provided CRs.
Edit the SiteConfig CR to include the search paths of any directories you have created. The first directory that is listed under extraManifests.searchPaths must be the directory containing the reference manifests. Consider the order in which the directories are listed. In cases where directories contain files with the same name, the file in the final directory takes precedence.
Example SiteConfig CR
```
extraManifests:
    searchPaths:
    - extra-manifest/ 1
    - custom-manifest/ 2
```
1
The directory containing the reference manifests must be listed first under extraManifests.searchPaths.
2
If you are using user-provided CRs, the last directory listed under extraManifests.searchPaths in the SiteConfig CR must be the directory containing those user-provided CRs.
Edit the top-level kustomization.yaml file to control which OpenShift Container Platform versions are active. The following is an example of a kustomization.yaml file at the top level:
```
resources:
- version_4.13 1
#- version_4.14 2
```
1
Activate version 4.13.
2
Use comments to deactivate a version.

18.3. Updating GitOps ZTP

You can update the GitOps Zero Touch Provisioning (ZTP) infrastructure independently from the hub cluster, Red Hat Advanced Cluster Management (RHACM), and the managed OpenShift Container Platform clusters.

Note

You can update the Red Hat OpenShift GitOps Operator when new versions become available. When updating the GitOps ZTP plugin, review the updated files in the reference configuration and ensure that the changes meet your requirements.

18.3.1. Overview of the GitOps ZTP update process

You can update GitOps Zero Touch Provisioning (ZTP) for a fully operational hub cluster running an earlier version of the GitOps ZTP infrastructure. The update process avoids impact on managed clusters.

Note

Any changes to policy settings, including adding recommended content, results in updated polices that must be rolled out to the managed clusters and reconciled.

At a high level, the strategy for updating the GitOps ZTP infrastructure is as follows:

Label all existing clusters with the ztp-done label.
Stop the ArgoCD applications.
Install the new GitOps ZTP tools.
Update required content and optional changes in the Git repository.
Update and restart the application configuration.

18.3.2. Preparing for the upgrade

Use the following procedure to prepare your site for the GitOps Zero Touch Provisioning (ZTP) upgrade.

Procedure

Get the latest version of the GitOps ZTP container that has the custom resources (CRs) used to configure Red Hat OpenShift GitOps for use with GitOps ZTP.
Extract the argocd/deployment directory by using the following commands:
```
$ mkdir -p ./update
```
```
$ podman run --log-driver=none --rm registry.redhat.io/openshift4/ztp-site-generate-rhel8:v4.14 extract /home/ztp --tar | tar x -C ./update
```
The /update directory contains the following subdirectories:
- update/extra-manifest: contains the source CR files that the SiteConfig CR uses to generate the extra manifest configMap.
- update/source-crs: contains the source CR files that the PolicyGenTemplate CR uses to generate the Red Hat Advanced Cluster Management (RHACM) policies.
- update/argocd/deployment: contains patches and YAML files to apply on the hub cluster for use in the next step of this procedure.
- update/argocd/example: contains example SiteConfig and PolicyGenTemplate files that represent the recommended configuration.
Update the clusters-app.yaml and policies-app.yaml files to reflect the name of your applications and the URL, branch, and path for your Git repository.
If the upgrade includes changes that results in obsolete policies, the obsolete policies should be removed prior to performing the upgrade.
Diff the changes between the configuration and deployment source CRs in the /update folder and Git repo where you manage your fleet site CRs. Apply and push the required changes to your site repository.
Important
When you update GitOps ZTP to the latest version, you must apply the changes from the update/argocd/deployment directory to your site repository. Do not use older versions of the argocd/deployment/ files.

18.3.3. Labeling the existing clusters

To ensure that existing clusters remain untouched by the tool updates, label all existing managed clusters with the ztp-done label.

Note

This procedure only applies when updating clusters that were not provisioned with Topology Aware Lifecycle Manager (TALM). Clusters that you provision with TALM are automatically labeled with ztp-done.

Procedure

Find a label selector that lists the managed clusters that were deployed with GitOps Zero Touch Provisioning (ZTP), such as local-cluster!=true:
```
$ oc get managedcluster -l 'local-cluster!=true'
```
Ensure that the resulting list contains all the managed clusters that were deployed with GitOps ZTP, and then use that selector to add the ztp-done label:
```
$ oc label managedcluster -l 'local-cluster!=true' ztp-done=
```

18.3.4. Stopping the existing GitOps ZTP applications

Removing the existing applications ensures that any changes to existing content in the Git repository are not rolled out until the new version of the tools is available.

Use the application files from the deployment directory. If you used custom names for the applications, update the names in these files first.

Procedure

Perform a non-cascaded delete on the clusters application to leave all generated resources in place:
```
$ oc delete -f update/argocd/deployment/clusters-app.yaml
```

Perform a cascaded delete on the policies application to remove all previous policies:

$ oc patch -f policies-app.yaml -p '{"metadata": {"finalizers": ["resources-finalizer.argocd.argoproj.io"]}}' --type merge

$ oc delete -f update/argocd/deployment/policies-app.yaml

18.3.5. Required changes to the Git repository

When upgrading the ztp-site-generate container from an earlier release of GitOps Zero Touch Provisioning (ZTP) to 4.10 or later, there are additional requirements for the contents of the Git repository. Existing content in the repository must be updated to reflect these changes.

Make required changes to PolicyGenTemplate files:
All PolicyGenTemplate files must be created in a Namespace prefixed with ztp. This ensures that the GitOps ZTP application is able to manage the policy CRs generated by GitOps ZTP without conflicting with the way Red Hat Advanced Cluster Management (RHACM) manages the policies internally.

Add the kustomization.yaml file to the repository:

All SiteConfig and PolicyGenTemplate CRs must be included in a kustomization.yaml file under their respective directory trees. For example:

├── policygentemplates
│   ├── site1-ns.yaml
│   ├── site1.yaml
│   ├── site2-ns.yaml
│   ├── site2.yaml
│   ├── common-ns.yaml
│   ├── common-ranGen.yaml
│   ├── group-du-sno-ranGen-ns.yaml
│   ├── group-du-sno-ranGen.yaml
│   └── kustomization.yaml
└── siteconfig
    ├── site1.yaml
    ├── site2.yaml
    └── kustomization.yaml

Note

The files listed in the generator sections must contain either SiteConfig or PolicyGenTemplate CRs only. If your existing YAML files contain other CRs, for example, Namespace, these other CRs must be pulled out into separate files and listed in the resources section.

The PolicyGenTemplate kustomization file must contain all PolicyGenTemplate YAML files in the generator section and Namespace CRs in the resources section. For example:

apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization

generators:
- common-ranGen.yaml
- group-du-sno-ranGen.yaml
- site1.yaml
- site2.yaml

resources:
- common-ns.yaml
- group-du-sno-ranGen-ns.yaml
- site1-ns.yaml
- site2-ns.yaml

The SiteConfig kustomization file must contain all SiteConfig YAML files in the generator section and any other CRs in the resources:

apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization

generators:
- site1.yaml
- site2.yaml

Remove the pre-sync.yaml and post-sync.yaml files.
In OpenShift Container Platform 4.10 and later, the pre-sync.yaml and post-sync.yaml files are no longer required. The update/deployment/kustomization.yaml CR manages the policies deployment on the hub cluster.
Note
There is a set of pre-sync.yaml and post-sync.yaml files under both the SiteConfig and PolicyGenTemplate trees.
Review and incorporate recommended changes
Each release may include additional recommended changes to the configuration applied to deployed clusters. Typically these changes result in lower CPU use by the OpenShift platform, additional features, or improved tuning of the platform.
Review the reference SiteConfig and PolicyGenTemplate CRs applicable to the types of cluster in your network. These examples can be found in the argocd/example directory extracted from the GitOps ZTP container.

18.3.6. Installing the new GitOps ZTP applications

Using the extracted argocd/deployment directory, and after ensuring that the applications point to your site Git repository, apply the full contents of the deployment directory. Applying the full contents of the directory ensures that all necessary resources for the applications are correctly configured.

Procedure

Select the multicluster-operators-subscription image that matches your RHACM version.

Table 18.7. multicluster-operators-subscription image versions
OpenShift Container Platform version	RHACM version	MCE version	MCE RHEL version	MCE image
4.14, 4.15, 4.16	2.8, 2.9	2.8, 2.9	RHEL 8	`registry.redhat.io/rhacm2/multicluster-operators-subscription-rhel8:v2.8` `registry.redhat.io/rhacm2/multicluster-operators-subscription-rhel8:v2.9`
4.14, 4.15, 4.16	2.10	2.10	RHEL 9	`registry.redhat.io/rhacm2/multicluster-operators-subscription-rhel9:v2.10`

Important

Add the following configuration to the out/argocd/deployment/argocd-openshift-gitops-patch.json file:

{
  "args": [
    "-c",
    "mkdir -p /.config/kustomize/plugin/policy.open-cluster-management.io/v1/policygenerator && cp /policy-generator/PolicyGenerator-not-fips-compliant /.config/kustomize/plugin/policy.open-cluster-management.io/v1/policygenerator/PolicyGenerator" 1
  ],
  "command": [
    "/bin/bash"
  ],
  "image": "registry.redhat.io/rhacm2/multicluster-operators-subscription-rhel9:v2.10", 2 3
  "name": "policy-generator-install",
  "imagePullPolicy": "Always",
  "volumeMounts": [
    {
      "mountPath": "/.config",
      "name": "kustomize"
    }
  ]
}

1: Optional: For RHEL 9 images, copy the required universal executable in the /policy-generator/PolicyGenerator-not-fips-compliant folder for the ArgoCD version.
2: Match the multicluster-operators-subscription image to the RHACM version.
3: In disconnected environments, replace the URL for the multicluster-operators-subscription image with the disconnected registry equivalent for your environment.

Patch the ArgoCD instance. Run the following command:

$ oc patch argocd openshift-gitops \
-n openshift-gitops --type=merge \
--patch-file out/argocd/deployment/argocd-openshift-gitops-patch.json

In RHACM 2.7 and later, the multicluster engine enables the cluster-proxy-addon feature by default. Apply the following patch to disable the cluster-proxy-addon feature and remove the relevant hub cluster and managed pods that are responsible for this add-on. Run the following command:
```
$ oc patch multiclusterengines.multicluster.openshift.io multiclusterengine --type=merge --patch-file out/argocd/deployment/disable-cluster-proxy-addon.json
```
Apply the pipeline configuration to your hub cluster by running the following command:
```
$ oc apply -k out/argocd/deployment
```

18.3.7. Rolling out the GitOps ZTP configuration changes

If any configuration changes were included in the upgrade due to implementing recommended changes, the upgrade process results in a set of policy CRs on the hub cluster in the Non-Compliant state. With the GitOps Zero Touch Provisioning (ZTP) version 4.10 and later ztp-site-generate container, these policies are set to inform mode and are not pushed to the managed clusters without an additional step by the user. This ensures that potentially disruptive changes to the clusters can be managed in terms of when the changes are made, for example, during a maintenance window, and how many clusters are updated concurrently.

To roll out the changes, create one or more ClusterGroupUpgrade CRs as detailed in the TALM documentation. The CR must contain the list of Non-Compliant policies that you want to push out to the managed clusters as well as a list or selector of which clusters should be included in the update.

Additional resources

For information about the Topology Aware Lifecycle Manager (TALM), see About the Topology Aware Lifecycle Manager configuration.
For information about creating ClusterGroupUpgrade CRs, see About the auto-created ClusterGroupUpgrade CR for ZTP.

18.4. Installing managed clusters with RHACM and SiteConfig resources

You can provision OpenShift Container Platform clusters at scale with Red Hat Advanced Cluster Management (RHACM) using the assisted service and the GitOps plugin policy generator with core-reduction technology enabled. The GitOps Zero Touch Provisioning (ZTP) pipeline performs the cluster installations. GitOps ZTP can be used in a disconnected environment.

18.4.1. GitOps ZTP and Topology Aware Lifecycle Manager

GitOps Zero Touch Provisioning (ZTP) generates installation and configuration CRs from manifests stored in Git. These artifacts are applied to a centralized hub cluster where Red Hat Advanced Cluster Management (RHACM), the assisted service, and the Topology Aware Lifecycle Manager (TALM) use the CRs to install and configure the managed cluster. The configuration phase of the GitOps ZTP pipeline uses the TALM to orchestrate the application of the configuration CRs to the cluster. There are several key integration points between GitOps ZTP and the TALM.

Inform policies

By default, GitOps ZTP creates all policies with a remediation action of inform. These policies cause RHACM to report on compliance status of clusters relevant to the policies but does not apply the desired configuration. During the GitOps ZTP process, after OpenShift installation, the TALM steps through the created inform policies and enforces them on the target managed cluster(s). This applies the configuration to the managed cluster. Outside of the GitOps ZTP phase of the cluster lifecycle, this allows you to change policies without the risk of immediately rolling those changes out to affected managed clusters. You can control the timing and the set of remediated clusters by using TALM.

Automatic creation of ClusterGroupUpgrade CRs

To automate the initial configuration of newly deployed clusters, TALM monitors the state of all ManagedCluster CRs on the hub cluster. Any ManagedCluster CR that does not have a ztp-done label applied, including newly created ManagedCluster CRs, causes the TALM to automatically create a ClusterGroupUpgrade CR with the following characteristics:

The ClusterGroupUpgrade CR is created and enabled in the ztp-install namespace.
ClusterGroupUpgrade CR has the same name as the ManagedCluster CR.
The cluster selector includes only the cluster associated with that ManagedCluster CR.
The set of managed policies includes all policies that RHACM has bound to the cluster at the time the ClusterGroupUpgrade is created.
Pre-caching is disabled.
Timeout set to 4 hours (240 minutes).

The automatic creation of an enabled ClusterGroupUpgrade ensures that initial zero-touch deployment of clusters proceeds without the need for user intervention. Additionally, the automatic creation of a ClusterGroupUpgrade CR for any ManagedCluster without the ztp-done label allows a failed GitOps ZTP installation to be restarted by simply deleting the ClusterGroupUpgrade CR for the cluster.

Waves

Each policy generated from a PolicyGenTemplate CR includes a ztp-deploy-wave annotation. This annotation is based on the same annotation from each CR which is included in that policy. The wave annotation is used to order the policies in the auto-generated ClusterGroupUpgrade CR. The wave annotation is not used other than for the auto-generated ClusterGroupUpgrade CR.

Note

All CRs in the same policy must have the same setting for the ztp-deploy-wave annotation. The default value of this annotation for each CR can be overridden in the PolicyGenTemplate. The wave annotation in the source CR is used for determining and setting the policy wave annotation. This annotation is removed from each built CR which is included in the generated policy at runtime.

The TALM applies the configuration policies in the order specified by the wave annotations. The TALM waits for each policy to be compliant before moving to the next policy. It is important to ensure that the wave annotation for each CR takes into account any prerequisites for those CRs to be applied to the cluster. For example, an Operator must be installed before or concurrently with the configuration for the Operator. Similarly, the CatalogSource for an Operator must be installed in a wave before or concurrently with the Operator Subscription. The default wave value for each CR takes these prerequisites into account.

Multiple CRs and policies can share the same wave number. Having fewer policies can result in faster deployments and lower CPU usage. It is a best practice to group many CRs into relatively few waves.

To check the default wave value in each source CR, run the following command against the out/source-crs directory that is extracted from the ztp-site-generate container image:

$ grep -r "ztp-deploy-wave" out/source-crs

Phase labels

The ClusterGroupUpgrade CR is automatically created and includes directives to annotate the ManagedCluster CR with labels at the start and end of the GitOps ZTP process.

When GitOps ZTP configuration postinstallation commences, the ManagedCluster has the ztp-running label applied. When all policies are remediated to the cluster and are fully compliant, these directives cause the TALM to remove the ztp-running label and apply the ztp-done label.

For deployments that make use of the informDuValidator policy, the ztp-done label is applied when the cluster is fully ready for deployment of applications. This includes all reconciliation and resulting effects of the GitOps ZTP applied configuration CRs. The ztp-done label affects automatic ClusterGroupUpgrade CR creation by TALM. Do not manipulate this label after the initial GitOps ZTP installation of the cluster.

Linked CRs

The automatically created ClusterGroupUpgrade CR has the owner reference set as the ManagedCluster from which it was derived. This reference ensures that deleting the ManagedCluster CR causes the instance of the ClusterGroupUpgrade to be deleted along with any supporting resources.

18.4.2. Overview of deploying managed clusters with GitOps ZTP

Red Hat Advanced Cluster Management (RHACM) uses GitOps Zero Touch Provisioning (ZTP) to deploy single-node OpenShift Container Platform clusters, three-node clusters, and standard clusters. You manage site configuration data as OpenShift Container Platform custom resources (CRs) in a Git repository. GitOps ZTP uses a declarative GitOps approach for a develop once, deploy anywhere model to deploy the managed clusters.

The deployment of the clusters includes:

Installing the host operating system (RHCOS) on a blank server
Deploying OpenShift Container Platform
Creating cluster policies and site subscriptions
Making the necessary network configurations to the server operating system
Deploying profile Operators and performing any needed software-related configuration, such as performance profile, PTP, and SR-IOV

Overview of the managed site installation process

After you apply the managed site custom resources (CRs) on the hub cluster, the following actions happen automatically:

A Discovery image ISO file is generated and booted on the target host.
When the ISO file successfully boots on the target host it reports the host hardware information to RHACM.
After all hosts are discovered, OpenShift Container Platform is installed.
When OpenShift Container Platform finishes installing, the hub installs the klusterlet service on the target cluster.
The requested add-on services are installed on the target cluster.

The Discovery image ISO process is complete when the Agent CR for the managed cluster is created on the hub cluster.

Important

The target bare-metal host must meet the networking, firmware, and hardware requirements listed in Recommended single-node OpenShift cluster configuration for vDU application workloads.

18.4.3. Creating the managed bare-metal host secrets

Add the required Secret custom resources (CRs) for the managed bare-metal host to the hub cluster. You need a secret for the GitOps Zero Touch Provisioning (ZTP) pipeline to access the Baseboard Management Controller (BMC) and a secret for the assisted installer service to pull cluster installation images from the registry.

Note

The secrets are referenced from the SiteConfig CR by name. The namespace must match the SiteConfig namespace.

Procedure

Create a YAML secret file containing credentials for the host Baseboard Management Controller (BMC) and a pull secret required for installing OpenShift and all add-on cluster Operators:
1. Save the following YAML as the file example-sno-secret.yaml:
```
apiVersion: v1
kind: Secret
metadata:
  name: example-sno-bmc-secret
  namespace: example-sno 1
data: 2
  password: <base64_password>
  username: <base64_username>
type: Opaque
---
apiVersion: v1
kind: Secret
metadata:
  name: pull-secret
  namespace: example-sno  3
data:
  .dockerconfigjson: <pull_secret> 4
type: kubernetes.io/dockerconfigjson
```
  1
  Must match the namespace configured in the related SiteConfig CR
  2
  Base64-encoded values for password and username
  3
  Must match the namespace configured in the related SiteConfig CR
  4
  Base64-encoded pull secret
Add the relative path to example-sno-secret.yaml to the kustomization.yaml file that you use to install the cluster.

18.4.4. Configuring Discovery ISO kernel arguments for installations using GitOps ZTP

The GitOps Zero Touch Provisioning (ZTP) workflow uses the Discovery ISO as part of the OpenShift Container Platform installation process on managed bare-metal hosts. You can edit the InfraEnv resource to specify kernel arguments for the Discovery ISO. This is useful for cluster installations with specific environmental requirements. For example, configure the rd.net.timeout.carrier kernel argument for the Discovery ISO to facilitate static networking for the cluster or to receive a DHCP address before downloading the root file system during installation.

Note

In OpenShift Container Platform 4.14, you can only add kernel arguments. You can not replace or delete kernel arguments.

Prerequisites

You have installed the OpenShift CLI (oc).
You have logged in to the hub cluster as a user with cluster-admin privileges.

Procedure

Create the InfraEnv CR and edit the spec.kernelArguments specification to configure kernel arguments.

Save the following YAML in an InfraEnv-example.yaml file:

Note

The InfraEnv CR in this example uses template syntax such as {{ .Cluster.ClusterName }} that is populated based on values in the SiteConfig CR. The SiteConfig CR automatically populates values for these templates during deployment. Do not edit the templates manually.

apiVersion: agent-install.openshift.io/v1beta1
kind: InfraEnv
metadata:
  annotations:
    argocd.argoproj.io/sync-wave: "1"
  name: "{{ .Cluster.ClusterName }}"
  namespace: "{{ .Cluster.ClusterName }}"
spec:
  clusterRef:
    name: "{{ .Cluster.ClusterName }}"
    namespace: "{{ .Cluster.ClusterName }}"
  kernelArguments:
    - operation: append 1
      value: audit=0 2
    - operation: append
      value: trace=1
  sshAuthorizedKey: "{{ .Site.SshPublicKey }}"
  proxy: "{{ .Cluster.ProxySettings }}"
  pullSecretRef:
    name: "{{ .Site.PullSecretRef.Name }}"
  ignitionConfigOverride: "{{ .Cluster.IgnitionConfigOverride }}"
  nmStateConfigLabelSelector:
    matchLabels:
      nmstate-label: "{{ .Cluster.ClusterName }}"
  additionalNTPSources: "{{ .Cluster.AdditionalNTPSources }}"

1: Specify the append operation to add a kernel argument.
2: Specify the kernel argument you want to configure. This example configures the audit kernel argument and the trace kernel argument.

Commit the InfraEnv-example.yaml CR to the same location in your Git repository that has the SiteConfig CR and push your changes. The following example shows a sample Git repository structure:
```
~/example-ztp/install
          └── site-install
               ├── siteconfig-example.yaml
               ├── InfraEnv-example.yaml
               ...
```
Edit the spec.clusters.crTemplates specification in the SiteConfig CR to reference the InfraEnv-example.yaml CR in your Git repository:
```
clusters:
  crTemplates:
    InfraEnv: "InfraEnv-example.yaml"
```
When you are ready to deploy your cluster by committing and pushing the SiteConfig CR, the build pipeline uses the custom InfraEnv-example CR in your Git repository to configure the infrastructure environment, including the custom kernel arguments.

Verification

To verify that the kernel arguments are applied, after the Discovery image verifies that OpenShift Container Platform is ready for installation, you can SSH to the target host before the installation process begins. At that point, you can view the kernel arguments for the Discovery ISO in the /proc/cmdline file.

Begin an SSH session with the target host:

$ ssh -i /path/to/privatekey core@<host_name>

View the system’s kernel arguments by using the following command:
```
$ cat /proc/cmdline
```

18.4.5. Deploying a managed cluster with SiteConfig and GitOps ZTP

Use the following procedure to create a SiteConfig custom resource (CR) and related files and initiate the GitOps Zero Touch Provisioning (ZTP) cluster deployment.

Prerequisites

You have installed the OpenShift CLI (oc).
You have logged in to the hub cluster as a user with cluster-admin privileges.
You configured the hub cluster for generating the required installation and policy CRs.
You created a Git repository where you manage your custom site configuration data. The repository must be accessible from the hub cluster and you must configure it as a source repository for the ArgoCD application. See "Preparing the GitOps ZTP site configuration repository" for more information.
Note
When you create the source repository, ensure that you patch the ArgoCD application with the argocd/deployment/argocd-openshift-gitops-patch.json patch-file that you extract from the ztp-site-generate container. See "Configuring the hub cluster with ArgoCD".
To be ready for provisioning managed clusters, you require the following for each bare-metal host:
Network connectivity
Your network requires DNS. Managed cluster hosts should be reachable from the hub cluster. Ensure that Layer 3 connectivity exists between the hub cluster and the managed cluster host.
Baseboard Management Controller (BMC) details
GitOps ZTP uses BMC username and password details to connect to the BMC during cluster installation. The GitOps ZTP plugin manages the ManagedCluster CRs on the hub cluster based on the SiteConfig CR in your site Git repo. You create individual BMCSecret CRs for each host manually.

Procedure

Create the required managed cluster secrets on the hub cluster. These resources must be in a namespace with a name matching the cluster name. For example, in out/argocd/example/siteconfig/example-sno.yaml, the cluster name and namespace is example-sno.
1. Export the cluster namespace by running the following command:
```
$ export CLUSTERNS=example-sno
```
2. Create the namespace:
```
$ oc create namespace $CLUSTERNS
```
Create pull secret and BMC Secret CRs for the managed cluster. The pull secret must contain all the credentials necessary for installing OpenShift Container Platform and all required Operators. See "Creating the managed bare-metal host secrets" for more information.
Note
The secrets are referenced from the SiteConfig custom resource (CR) by name. The namespace must match the SiteConfig namespace.

Create a SiteConfig CR for your cluster in your local clone of the Git repository:

Choose the appropriate example for your CR from the out/argocd/example/siteconfig/ folder. The folder includes example files for single node, three-node, and standard clusters:
- example-sno.yaml
- example-3node.yaml
- example-standard.yaml

Change the cluster and host details in the example file to match the type of cluster you want. For example:

Example single-node OpenShift SiteConfig CR

# example-node1-bmh-secret & assisted-deployment-pull-secret need to be created under same namespace example-sno
---
apiVersion: ran.openshift.io/v1
kind: SiteConfig
metadata:
  name: "example-sno"
  namespace: "example-sno"
spec:
  baseDomain: "example.com"
  pullSecretRef:
    name: "assisted-deployment-pull-secret"
  clusterImageSetNameRef: "openshift-4.10"
  sshPublicKey: "ssh-rsa AAAA..."
  clusters:
  - clusterName: "example-sno"
    networkType: "OVNKubernetes"
    # installConfigOverrides is a generic way of passing install-config
    # parameters through the siteConfig.  The 'capabilities' field configures
    # the composable openshift feature.  In this 'capabilities' setting, we
    # remove all but the marketplace component from the optional set of
    # components.
    # Notes:
    # - OperatorLifecycleManager is needed for 4.15 and later
    # - NodeTuning is needed for 4.13 and later, not for 4.12 and earlier
    installConfigOverrides: |
      {
        "capabilities": {
          "baselineCapabilitySet": "None",
          "additionalEnabledCapabilities": [
            "NodeTuning",
            "OperatorLifecycleManager"
          ]
        }
      }
    # It is strongly recommended to include crun manifests as part of the additional install-time manifests for 4.13+.
    # The crun manifests can be obtained from source-crs/optional-extra-manifest/ and added to the git repo ie.sno-extra-manifest.
    # extraManifestPath: sno-extra-manifest
    clusterLabels:
      # These example cluster labels correspond to the bindingRules in the PolicyGenTemplate examples
      du-profile: "latest"
      # These example cluster labels correspond to the bindingRules in the PolicyGenTemplate examples in ../policygentemplates:
      # ../policygentemplates/common-ranGen.yaml will apply to all clusters with 'common: true'
      common: true
      # ../policygentemplates/group-du-sno-ranGen.yaml will apply to all clusters with 'group-du-sno: ""'
      group-du-sno: ""
      # ../policygentemplates/example-sno-site.yaml will apply to all clusters with 'sites: "example-sno"'
      # Normally this should match or contain the cluster name so it only applies to a single cluster
      sites : "example-sno"
    clusterNetwork:
      - cidr: 1001:1::/48
        hostPrefix: 64
    machineNetwork:
      - cidr: 1111:2222:3333:4444::/64
    serviceNetwork:
      - 1001:2::/112
    additionalNTPSources:
      - 1111:2222:3333:4444::2
    # Initiates the cluster for workload partitioning. Setting specific reserved/isolated CPUSets is done via PolicyTemplate
    # please see Workload Partitioning Feature for a complete guide.
    cpuPartitioningMode: AllNodes
    # Optionally; This can be used to override the KlusterletAddonConfig that is created for this cluster:
    #crTemplates:
    #  KlusterletAddonConfig: "KlusterletAddonConfigOverride.yaml"
    nodes:
      - hostName: "example-node1.example.com"
        role: "master"
        # Optionally; This can be used to configure desired BIOS setting on a host:
        #biosConfigRef:
        #  filePath: "example-hw.profile"
        bmcAddress: "idrac-virtualmedia+https://[1111:2222:3333:4444::bbbb:1]/redfish/v1/Systems/System.Embedded.1"
        bmcCredentialsName:
          name: "example-node1-bmh-secret"
        bootMACAddress: "AA:BB:CC:DD:EE:11"
        # Use UEFISecureBoot to enable secure boot
        bootMode: "UEFI"
        rootDeviceHints:
          deviceName: "/dev/disk/by-path/pci-0000:01:00.0-scsi-0:2:0:0"
        # disk partition at `/var/lib/containers` with ignitionConfigOverride. Some values must be updated. See DiskPartitionContainer.md for more details
        ignitionConfigOverride: |
           {
            "ignition": {
              "version": "3.2.0"
            },
            "storage": {
              "disks": [
                {
                  "device": "/dev/disk/by-path/pci-0000:01:00.0-scsi-0:2:0:0",
                  "partitions": [
                    {
                     "label": "var-lib-containers",
                     "sizeMiB": 0,
                     "startMiB": 250000
                  }
              ],
              "wipeTable": false
             }
           ],
            "filesystems": [
              {
               "device": "/dev/disk/by-partlabel/var-lib-containers",
               "format": "xfs",
               "mountOptions": [
                 "defaults",
                 "prjquota"
                ],
                "path": "/var/lib/containers",
                "wipeFilesystem": true
               }
             ]
           },
           "systemd": {
             "units": [
               {
                "contents": "# Generated by Butane\n[Unit]\nRequires=systemd-fsck@dev-disk-by\\x2dpartlabel-var\\x2dlib\\x2dcontainers.service\nAfter=systemd-fsck@dev-disk-by\\x2dpartlabel-var\\x2dlib\\x2dcontainers.service\n\n[Mount]\nWhere=/var/lib/containers\nWhat=/dev/disk/by-partlabel/var-lib-containers\nType=xfs\nOptions=defaults,prjquota\n\n[Install]\nRequiredBy=local-fs.target",
                "enabled": true,
                "name": "var-lib-containers.mount"
               }
              ]
            }
           }
        nodeNetwork:
          interfaces:
            - name: eno1
              macAddress: "AA:BB:CC:DD:EE:11"
          config:
            interfaces:
              - name: eno1
                type: ethernet
                state: up
                ipv4:
                  enabled: false
                ipv6:
                  enabled: true
                  address:
                  # For SNO sites with static IP addresses, the node-specific,
                  # API and Ingress IPs should all be the same and configured on
                  # the interface
                  - ip: 1111:2222:3333:4444::aaaa:1
                    prefix-length: 64
            dns-resolver:
              config:
                search:
                - example.com
                server:
                - 1111:2222:3333:4444::2
            routes:
              config:
              - destination: ::/0
                next-hop-interface: eno1
                next-hop-address: 1111:2222:3333:4444::1
                table-id: 254

Note

For more information about BMC addressing, see the "Additional resources" section. The installConfigOverrides and ignitionConfigOverride fields are expanded in the example for ease of readability.

You can inspect the default set of extra-manifest MachineConfig CRs in out/argocd/extra-manifest. It is automatically applied to the cluster when it is installed.
Optional: To provision additional install-time manifests on the provisioned cluster, create a directory in your Git repository, for example, sno-extra-manifest/, and add your custom manifest CRs to this directory. If your SiteConfig.yaml refers to this directory in the extraManifestPath field, any CRs in this referenced directory are appended to the default set of extra manifests.
Enabling the crun OCI container runtime
For optimal cluster performance, enable crun for master and worker nodes in single-node OpenShift, single-node OpenShift with additional worker nodes, three-node OpenShift, and standard clusters.
Enable crun in a ContainerRuntimeConfig CR as an additional Day 0 install-time manifest to avoid the cluster having to reboot.
The enable-crun-master.yaml and enable-crun-worker.yaml CR files are in the out/source-crs/optional-extra-manifest/ folder that you can extract from the ztp-site-generate container. For more information, see "Customizing extra installation manifests in the GitOps ZTP pipeline".

Add the SiteConfig CR to the kustomization.yaml file in the generators section, similar to the example shown in out/argocd/example/siteconfig/kustomization.yaml.
Commit the SiteConfig CR and associated kustomization.yaml changes in your Git repository and push the changes.
The ArgoCD pipeline detects the changes and begins the managed cluster deployment.

Verification

Verify that the custom roles and labels are applied after the node is deployed:
```
$ oc describe node example-node.example.com
```

Example output

Name:   example-node.example.com
Roles:  control-plane,example-label,master,worker
Labels: beta.kubernetes.io/arch=amd64
        beta.kubernetes.io/os=linux
        custom-label/parameter1=true
        kubernetes.io/arch=amd64
        kubernetes.io/hostname=cnfdf03.telco5gran.eng.rdu2.redhat.com
        kubernetes.io/os=linux
        node-role.kubernetes.io/control-plane=
        node-role.kubernetes.io/example-label= 1
        node-role.kubernetes.io/master=
        node-role.kubernetes.io/worker=
        node.openshift.io/os_id=rhcos

1: The custom label is applied to the node.

Additional resources

Single-node OpenShift SiteConfig CR installation reference

18.4.5.1. Single-node OpenShift SiteConfig CR installation reference

Table 18.8. SiteConfig CR installation options for single-node OpenShift clusters
SiteConfig CR field	Description
`spec.cpuPartitioningMode`	Configure workload partitioning by setting the value for `cpuPartitioningMode` to `AllNodes`. To complete the configuration, specify the `isolated` and `reserved` CPUs in the `PerformanceProfile` CR. Note Configuring workload partitioning by using the `cpuPartitioningMode` field in the `SiteConfig` CR is a Tech Preview feature in OpenShift Container Platform 4.13.
`metadata.name`	Set `name` to `assisted-deployment-pull-secret` and create the `assisted-deployment-pull-secret` CR in the same namespace as the `SiteConfig` CR.
`spec.clusterImageSetNameRef`	Configure the image set available on the hub cluster for all the clusters in the site. To see the list of supported versions on your hub cluster, run `oc get clusterimagesets`.
`installConfigOverrides`	Set the `installConfigOverrides` field to enable or disable optional components prior to cluster installation. Important Use the reference configuration as specified in the example `SiteConfig` CR. Adding additional components back into the system might require additional reserved CPU capacity.
`spec.clusters.clusterImageSetNameRef`	Specifies the cluster image set used to deploy an individual cluster. If defined, it overrides the `spec.clusterImageSetNameRef` at site level.
`spec.clusters.clusterLabels`	Configure cluster labels to correspond to the `bindingRules` field in the `PolicyGenTemplate` CRs that you define. For example, `policygentemplates/common-ranGen.yaml` applies to all clusters with `common: true` set, `policygentemplates/group-du-sno-ranGen.yaml` applies to all clusters with `group-du-sno: ""` set.
`spec.clusters.crTemplates.KlusterletAddonConfig`	Optional. Set `KlusterletAddonConfig` to KlusterletAddonConfigOverride.yaml to override the default `KlusterletAddonConfig that is created for the cluster.
`spec.clusters.nodes.hostName`	For single-node deployments, define a single host. For three-node deployments, define three hosts. For standard deployments, define three hosts with `role: master` and two or more hosts defined with `role: worker`.
`spec.clusters.nodes.nodeLabels`	Specify custom roles for your nodes in your managed clusters. These are additional roles are not used by any OpenShift Container Platform components, only by the user. When you add a custom role, it can be associated with a custom machine config pool that references a specific configuration for that role. Adding custom labels or roles during installation makes the deployment process more effective and prevents the need for additional reboots after the installation is complete.
`spec.clusters.nodes.automatedCleaningMode`	Optional. Uncomment and set the value to `metadata` to enable the removal of the disk’s partitioning table only, without fully wiping the disk. The default value is `disabled`.
`spec.clusters.nodes.bmcAddress`	BMC address that you use to access the host. Applies to all cluster types. GitOps ZTP supports iPXE and virtual media booting by using Redfish or IPMI protocols. To use iPXE booting, you must use RHACM 2.8 or later. For more information about BMC addressing, see the "Additional resources" section.
`spec.clusters.nodes.bmcAddress`	BMC address that you use to access the host. Applies to all cluster types. GitOps ZTP supports iPXE and virtual media booting by using Redfish or IPMI protocols. To use iPXE booting, you must use RHACM 2.8 or later. For more information about BMC addressing, see the "Additional resources" section. Note In far edge Telco use cases, only virtual media is supported for use with GitOps ZTP.
`spec.clusters.nodes.bmcCredentialsName`	Configure the `bmh-secret` CR that you separately create with the host BMC credentials. When creating the `bmh-secret` CR, use the same namespace as the `SiteConfig` CR that provisions the host.
`spec.clusters.nodes.bootMode`	Set the boot mode for the host to `UEFI`. The default value is `UEFI`. Use `UEFISecureBoot` to enable secure boot on the host.
`spec.clusters.nodes.rootDeviceHints`	Specifies the device for deployment. Identifiers that are stable across reboots are recommended. For example, `wwn: <disk_wwn>` or `deviceName: /dev/disk/by-path/<device_path>`. `<by-path>` values are preferred. For a detailed list of stable identifiers, see the "About root device hints" section.
`spec.clusters.nodes.ignitionConfigOverride`	Optional. Use this field to assign partitions for persistent storage. Adjust disk ID and size to the specific hardware.
`spec.clusters.nodes.nodeNetwork`	Configure the network settings for the node.
`spec.clusters.nodes.nodeNetwork.config.interfaces.ipv6`	Configure the IPv6 address for the host. For single-node OpenShift clusters with static IP addresses, the node-specific API and Ingress IPs should be the same.

Additional resources

Customizing extra installation manifests in the GitOps ZTP pipeline
Preparing the GitOps ZTP site configuration repository
Configuring the hub cluster with ArgoCD
Signalling ZTP cluster deployment completion with validator inform policies
Creating the managed bare-metal host secrets
BMC addressing
About root device hints

18.4.6. Monitoring managed cluster installation progress

The ArgoCD pipeline uses the SiteConfig CR to generate the cluster configuration CRs and syncs it with the hub cluster. You can monitor the progress of the synchronization in the ArgoCD dashboard.

Prerequisites

You have installed the OpenShift CLI (oc).
You have logged in to the hub cluster as a user with cluster-admin privileges.

Procedure

When the synchronization is complete, the installation generally proceeds as follows:

The Assisted Service Operator installs OpenShift Container Platform on the cluster. You can monitor the progress of cluster installation from the RHACM dashboard or from the command line by running the following commands:
1. Export the cluster name:
```
$ export CLUSTER=<clusterName>
```
2. Query the AgentClusterInstall CR for the managed cluster:
```
$ oc get agentclusterinstall -n $CLUSTER $CLUSTER -o jsonpath='{.status.conditions[?(@.type=="Completed")]}' | jq
```
3. Get the installation events for the cluster:
```
$ curl -sk $(oc get agentclusterinstall -n $CLUSTER $CLUSTER -o jsonpath='{.status.debugInfo.eventsURL}')  | jq '.[-2,-1]'
```

18.4.7. Troubleshooting GitOps ZTP by validating the installation CRs

The ArgoCD pipeline uses the SiteConfig and PolicyGenTemplate custom resources (CRs) to generate the cluster configuration CRs and Red Hat Advanced Cluster Management (RHACM) policies. Use the following steps to troubleshoot issues that might occur during this process.

Prerequisites

You have installed the OpenShift CLI (oc).
You have logged in to the hub cluster as a user with cluster-admin privileges.

Procedure

Check that the installation CRs were created by using the following command:
```
$ oc get AgentClusterInstall -n <cluster_name>
```
If no object is returned, use the following steps to troubleshoot the ArgoCD pipeline flow from SiteConfig files to the installation CRs.
Verify that the ManagedCluster CR was generated using the SiteConfig CR on the hub cluster:
```
$ oc get managedcluster
```

If the ManagedCluster is missing, check if the clusters application failed to synchronize the files from the Git repository to the hub cluster:

$ oc describe -n openshift-gitops application clusters

Check for the Status.Conditions field to view the error logs for the managed cluster. For example, setting an invalid value for extraManifestPath: in the SiteConfig CR raises the following error:

Status:
  Conditions:
    Last Transition Time:  2021-11-26T17:21:39Z
    Message:               rpc error: code = Unknown desc = `kustomize build /tmp/https___git.com/ran-sites/siteconfigs/ --enable-alpha-plugins` failed exit status 1: 2021/11/26 17:21:40 Error could not create extra-manifest ranSite1.extra-manifest3 stat extra-manifest3: no such file or directory 2021/11/26 17:21:40 Error: could not build the entire SiteConfig defined by /tmp/kust-plugin-config-913473579: stat extra-manifest3: no such file or directory Error: failure in plugin configured via /tmp/kust-plugin-config-913473579; exit status 1: exit status 1
    Type:  ComparisonError

Check the Status.Sync field. If there are log errors, the Status.Sync field could indicate an Unknown error:

Status:
  Sync:
    Compared To:
      Destination:
        Namespace:  clusters-sub
        Server:     https://kubernetes.default.svc
      Source:
        Path:             sites-config
        Repo URL:         https://git.com/ran-sites/siteconfigs/.git
        Target Revision:  master
    Status:               Unknown

18.4.8. Troubleshooting GitOps ZTP virtual media booting on Supermicro servers

SuperMicro X11 servers do not support virtual media installations when the image is served using the https protocol. As a result, single-node OpenShift deployments for this environment fail to boot on the target node. To avoid this issue, log in to the hub cluster and disable Transport Layer Security (TLS) in the Provisioning resource. This ensures the image is not served with TLS even though the image address uses the https scheme.

Prerequisites

You have installed the OpenShift CLI (oc).
You have logged in to the hub cluster as a user with cluster-admin privileges.

Procedure

Disable TLS in the Provisioning resource by running the following command:

$ oc patch provisioning provisioning-configuration --type merge -p '{"spec":{"disableVirtualMediaTLS": true}}'

Continue the steps to deploy your single-node OpenShift cluster.

18.4.9. Removing a managed cluster site from the GitOps ZTP pipeline

You can remove a managed site and the associated installation and configuration policy CRs from the GitOps Zero Touch Provisioning (ZTP) pipeline.

Prerequisites

You have installed the OpenShift CLI (oc).
You have logged in to the hub cluster as a user with cluster-admin privileges.

Procedure

Remove a site and the associated CRs by removing the associated SiteConfig and PolicyGenTemplate files from the kustomization.yaml file.
Add the following syncOptions field to your SiteConfig application:
```
kind: Application
spec:
  syncPolicy:
    syncOptions:
    - PrunePropagationPolicy=background
```
When you run the GitOps ZTP pipeline again, the generated CRs are removed.
Optional: If you want to permanently remove a site, you should also remove the SiteConfig and site-specific PolicyGenTemplate files from the Git repository.
Optional: If you want to remove a site temporarily, for example when redeploying a site, you can leave the SiteConfig and site-specific PolicyGenTemplate CRs in the Git repository.

Additional resources

For information about removing a cluster, see Removing a cluster from management.

18.4.10. Removing obsolete content from the GitOps ZTP pipeline

If a change to the PolicyGenTemplate configuration results in obsolete policies, for example, if you rename policies, use the following procedure to remove the obsolete policies.

Prerequisites

You have installed the OpenShift CLI (oc).
You have logged in to the hub cluster as a user with cluster-admin privileges.

Procedure

Remove the affected PolicyGenTemplate files from the Git repository, commit and push to the remote repository.
Wait for the changes to synchronize through the application and the affected policies to be removed from the hub cluster.
Add the updated PolicyGenTemplate files back to the Git repository, and then commit and push to the remote repository.
Note
Removing GitOps Zero Touch Provisioning (ZTP) policies from the Git repository, and as a result also removing them from the hub cluster, does not affect the configuration of the managed cluster. The policy and CRs managed by that policy remains in place on the managed cluster.
Optional: As an alternative, after making changes to PolicyGenTemplate CRs that result in obsolete policies, you can remove these policies from the hub cluster manually. You can delete policies from the RHACM console using the Governance tab or by running the following command:
```
$ oc delete policy -n <namespace> <policy_name>
```

18.4.11. Tearing down the GitOps ZTP pipeline

You can remove the ArgoCD pipeline and all generated GitOps Zero Touch Provisioning (ZTP) artifacts.

Prerequisites

You have installed the OpenShift CLI (oc).
You have logged in to the hub cluster as a user with cluster-admin privileges.

Procedure

Detach all clusters from Red Hat Advanced Cluster Management (RHACM) on the hub cluster.
Delete the kustomization.yaml file in the deployment directory using the following command:
```
$ oc delete -k out/argocd/deployment
```
Commit and push your changes to the site repository.

18.5. Configuring managed clusters with policies and PolicyGenTemplate resources

Applied policy custom resources (CRs) configure the managed clusters that you provision. You can customize how Red Hat Advanced Cluster Management (RHACM) uses PolicyGenTemplate CRs to generate the applied policy CRs.

18.5.1. About the PolicyGenTemplate CRD

The PolicyGenTemplate custom resource definition (CRD) tells the PolicyGen policy generator what custom resources (CRs) to include in the cluster configuration, how to combine the CRs into the generated policies, and what items in those CRs need to be updated with overlay content.

The following example shows a PolicyGenTemplate CR (common-du-ranGen.yaml) extracted from the ztp-site-generate reference container. The common-du-ranGen.yaml file defines two Red Hat Advanced Cluster Management (RHACM) policies. The polices manage a collection of configuration CRs, one for each unique value of policyName in the CR. common-du-ranGen.yaml creates a single placement binding and a placement rule to bind the policies to clusters based on the labels listed in the bindingRules section.

Example PolicyGenTemplate CR - common-du-ranGen.yaml

---
apiVersion: ran.openshift.io/v1
kind: PolicyGenTemplate
metadata:
  name: "common"
  namespace: "ztp-common"
spec:
  bindingRules:
    common: "true" 1
  sourceFiles: 2
    - fileName: SriovSubscription.yaml
      policyName: "subscriptions-policy"
    - fileName: SriovSubscriptionNS.yaml
      policyName: "subscriptions-policy"
    - fileName: SriovSubscriptionOperGroup.yaml
      policyName: "subscriptions-policy"
    - fileName: SriovOperatorStatus.yaml
      policyName: "subscriptions-policy"
    - fileName: PtpSubscription.yaml
      policyName: "subscriptions-policy"
    - fileName: PtpSubscriptionNS.yaml
      policyName: "subscriptions-policy"
    - fileName: PtpSubscriptionOperGroup.yaml
      policyName: "subscriptions-policy"
    - fileName: PtpOperatorStatus.yaml
      policyName: "subscriptions-policy"
    - fileName: ClusterLogNS.yaml
      policyName: "subscriptions-policy"
    - fileName: ClusterLogOperGroup.yaml
      policyName: "subscriptions-policy"
    - fileName: ClusterLogSubscription.yaml
      policyName: "subscriptions-policy"
    - fileName: ClusterLogOperatorStatus.yaml
      policyName: "subscriptions-policy"
    - fileName: StorageNS.yaml
      policyName: "subscriptions-policy"
    - fileName: StorageOperGroup.yaml
      policyName: "subscriptions-policy"
    - fileName: StorageSubscription.yaml
      policyName: "subscriptions-policy"
    - fileName: StorageOperatorStatus.yaml
      policyName: "subscriptions-policy"
    - fileName: ReduceMonitoringFootprint.yaml
      policyName: "config-policy"
    - fileName: OperatorHub.yaml 3
      policyName: "config-policy"
    - fileName: DefaultCatsrc.yaml 4
      policyName: "config-policy" 5
      metadata:
        name: redhat-operators
      spec:
        displayName: disconnected-redhat-operators
        image: registry.example.com:5000/disconnected-redhat-operators/disconnected-redhat-operator-index:v4.9
    - fileName: DisconnectedICSP.yaml
      policyName: "config-policy"
      spec:
        repositoryDigestMirrors:
        - mirrors:
          - registry.example.com:5000
          source: registry.redhat.io

1: common: "true" applies the policies to all clusters with this label.
2: Files listed under sourceFiles create the Operator policies for installed clusters.
3: OperatorHub.yaml configures the OperatorHub for the disconnected registry.
4: DefaultCatsrc.yaml configures the catalog source for the disconnected registry.
5: policyName: "config-policy" configures Operator subscriptions. The OperatorHub CR disables the default and this CR replaces redhat-operators with a CatalogSource CR that points to the disconnected registry.

A PolicyGenTemplate CR can be constructed with any number of included CRs. Apply the following example CR in the hub cluster to generate a policy containing a single CR:

apiVersion: ran.openshift.io/v1
kind: PolicyGenTemplate
metadata:
  name: "group-du-sno"
  namespace: "ztp-group"
spec:
  bindingRules:
    group-du-sno: ""
  mcp: "master"
  sourceFiles:
    - fileName: PtpConfigSlave.yaml
      policyName: "config-policy"
      metadata:
        name: "du-ptp-slave"
      spec:
        profile:
        - name: "slave"
          interface: "ens5f0"
          ptp4lOpts: "-2 -s --summary_interval -4"
          phc2sysOpts: "-a -r -n 24"

Using the source file PtpConfigSlave.yaml as an example, the file defines a PtpConfig CR. The generated policy for the PtpConfigSlave example is named group-du-sno-config-policy. The PtpConfig CR defined in the generated group-du-sno-config-policy is named du-ptp-slave. The spec defined in PtpConfigSlave.yaml is placed under du-ptp-slave along with the other spec items defined under the source file.

The following example shows the group-du-sno-config-policy CR:

apiVersion: policy.open-cluster-management.io/v1
kind: Policy
metadata:
  name: group-du-ptp-config-policy
  namespace: groups-sub
  annotations:
    policy.open-cluster-management.io/categories: CM Configuration Management
    policy.open-cluster-management.io/controls: CM-2 Baseline Configuration
    policy.open-cluster-management.io/standards: NIST SP 800-53
spec:
    remediationAction: inform
    disabled: false
    policy-templates:
        - objectDefinition:
            apiVersion: policy.open-cluster-management.io/v1
            kind: ConfigurationPolicy
            metadata:
                name: group-du-ptp-config-policy-config
            spec:
                remediationAction: inform
                severity: low
                namespaceselector:
                    exclude:
                        - kube-*
                    include:
                        - '*'
                object-templates:
                    - complianceType: musthave
                      objectDefinition:
                        apiVersion: ptp.openshift.io/v1
                        kind: PtpConfig
                        metadata:
                            name: du-ptp-slave
                            namespace: openshift-ptp
                        spec:
                            recommend:
                                - match:
                                - nodeLabel: node-role.kubernetes.io/worker-du
                                  priority: 4
                                  profile: slave
                            profile:
                                - interface: ens5f0
                                  name: slave
                                  phc2sysOpts: -a -r -n 24
                                  ptp4lConf: |
                                    [global]
                                    #
                                    # Default Data Set
                                    #
                                    twoStepFlag 1
                                    slaveOnly 0
                                    priority1 128
                                    priority2 128
                                    domainNumber 24
                                    .....

18.5.2. Recommendations when customizing PolicyGenTemplate CRs

Consider the following best practices when customizing site configuration PolicyGenTemplate custom resources (CRs):

Use as few policies as are necessary. Using fewer policies requires less resources. Each additional policy creates overhead for the hub cluster and the deployed managed cluster. CRs are combined into policies based on the policyName field in the PolicyGenTemplate CR. CRs in the same PolicyGenTemplate which have the same value for policyName are managed under a single policy.
In disconnected environments, use a single catalog source for all Operators by configuring the registry as a single index containing all Operators. Each additional CatalogSource CR on the managed clusters increases CPU usage.
MachineConfig CRs should be included as extraManifests in the SiteConfig CR so that they are applied during installation. This can reduce the overall time taken until the cluster is ready to deploy applications.
PolicyGenTemplates should override the channel field to explicitly identify the desired version. This ensures that changes in the source CR during upgrades does not update the generated subscription.

Additional resources

For recommendations about scaling clusters with RHACM, see Performance and scalability.

Note

When managing large numbers of spoke clusters on the hub cluster, minimize the number of policies to reduce resource consumption.

Grouping multiple configuration CRs into a single or limited number of policies is one way to reduce the overall number of policies on the hub cluster. When using the common, group, and site hierarchy of policies for managing site configuration, it is especially important to combine site-specific configuration into a single policy.

18.5.3. PolicyGenTemplate CRs for RAN deployments

Use PolicyGenTemplate (PGT) custom resources (CRs) to customize the configuration applied to the cluster by using the GitOps Zero Touch Provisioning (ZTP) pipeline. The PGT CR allows you to generate one or more policies to manage the set of configuration CRs on your fleet of clusters. The PGT identifies the set of managed CRs, bundles them into policies, builds the policy wrapping around those CRs, and associates the policies with clusters by using label binding rules.

The reference configuration, obtained from the GitOps ZTP container, is designed to provide a set of critical features and node tuning settings that ensure the cluster can support the stringent performance and resource utilization constraints typical of RAN (Radio Access Network) Distributed Unit (DU) applications. Changes or omissions from the baseline configuration can affect feature availability, performance, and resource utilization. Use the reference PolicyGenTemplate CRs as the basis to create a hierarchy of configuration files tailored to your specific site requirements.

The baseline PolicyGenTemplate CRs that are defined for RAN DU cluster configuration can be extracted from the GitOps ZTP ztp-site-generate container. See "Preparing the GitOps ZTP site configuration repository" for further details.

The PolicyGenTemplate CRs can be found in the ./out/argocd/example/policygentemplates folder. The reference architecture has common, group, and site-specific configuration CRs. Each PolicyGenTemplate CR refers to other CRs that can be found in the ./out/source-crs folder.

The PolicyGenTemplate CRs relevant to RAN cluster configuration are described below. Variants are provided for the group PolicyGenTemplate CRs to account for differences in single-node, three-node compact, and standard cluster configurations. Similarly, site-specific configuration variants are provided for single-node clusters and multi-node (compact or standard) clusters. Use the group and site-specific configuration variants that are relevant for your deployment.

Table 18.9. PolicyGenTemplate CRs for RAN deployments
PolicyGenTemplate CR	Description
`example-multinode-site.yaml`	Contains a set of CRs that get applied to multi-node clusters. These CRs configure SR-IOV features typical for RAN installations.
`example-sno-site.yaml`	Contains a set of CRs that get applied to single-node OpenShift clusters. These CRs configure SR-IOV features typical for RAN installations.
`common-ranGen.yaml`	Contains a set of common RAN CRs that get applied to all clusters. These CRs subscribe to a set of operators providing cluster features typical for RAN as well as baseline cluster tuning.
`group-du-3node-ranGen.yaml`	Contains the RAN policies for three-node clusters only.
`group-du-sno-ranGen.yaml`	Contains the RAN policies for single-node clusters only.
`group-du-standard-ranGen.yaml`	Contains the RAN policies for standard three control-plane clusters.
`group-du-3node-validator-ranGen.yaml`	`PolicyGenTemplate` CR used to generate the various policies required for three-node clusters.
`group-du-standard-validator-ranGen.yaml`	`PolicyGenTemplate` CR used to generate the various policies required for standard clusters.
`group-du-sno-validator-ranGen.yaml`	`PolicyGenTemplate` CR used to generate the various policies required for single-node OpenShift clusters.

Additional resources

Preparing the GitOps ZTP site configuration repository

18.5.4. Customizing a managed cluster with PolicyGenTemplate CRs

Use the following procedure to customize the policies that get applied to the managed cluster that you provision using the GitOps Zero Touch Provisioning (ZTP) pipeline.

Prerequisites

You have installed the OpenShift CLI (oc).
You have logged in to the hub cluster as a user with cluster-admin privileges.
You configured the hub cluster for generating the required installation and policy CRs.
You created a Git repository where you manage your custom site configuration data. The repository must be accessible from the hub cluster and be defined as a source repository for the Argo CD application.

Procedure

Create a PolicyGenTemplate CR for site-specific configuration CRs.
1. Choose the appropriate example for your CR from the out/argocd/example/policygentemplates folder, for example, example-sno-site.yaml or example-multinode-site.yaml.
2. Change the bindingRules field in the example file to match the site-specific label included in the SiteConfig CR. In the example SiteConfig file, the site-specific label is sites: example-sno.
  Note
  Ensure that the labels defined in your PolicyGenTemplate bindingRules field correspond to the labels that are defined in the related managed clusters SiteConfig CR.
3. Change the content in the example file to match the desired configuration.
Optional: Create a PolicyGenTemplate CR for any common configuration CRs that apply to the entire fleet of clusters.
1. Select the appropriate example for your CR from the out/argocd/example/policygentemplates folder, for example, common-ranGen.yaml.
2. Change the content in the example file to match the desired configuration.
Optional: Create a PolicyGenTemplate CR for any group configuration CRs that apply to the certain groups of clusters in the fleet.
Ensure that the content of the overlaid spec files matches your desired end state. As a reference, the out/source-crs directory contains the full list of source-crs available to be included and overlaid by your PolicyGenTemplate templates.
Note
Depending on the specific requirements of your clusters, you might need more than a single group policy per cluster type, especially considering that the example group policies each have a single PerformancePolicy.yaml file that can only be shared across a set of clusters if those clusters consist of identical hardware configurations.
1. Select the appropriate example for your CR from the out/argocd/example/policygentemplates folder, for example, group-du-sno-ranGen.yaml.
2. Change the content in the example file to match the desired configuration.
Optional. Create a validator inform policy PolicyGenTemplate CR to signal when the GitOps ZTP installation and configuration of the deployed cluster is complete. For more information, see "Creating a validator inform policy".
Define all the policy namespaces in a YAML file similar to the example out/argocd/example/policygentemplates/ns.yaml file.
Important
Do not include the Namespace CR in the same file with the PolicyGenTemplate CR.
Add the PolicyGenTemplate CRs and Namespace CR to the kustomization.yaml file in the generators section, similar to the example shown in out/argocd/example/policygentemplates/kustomization.yaml.
Commit the PolicyGenTemplate CRs, Namespace CR, and associated kustomization.yaml file in your Git repository and push the changes.
The ArgoCD pipeline detects the changes and begins the managed cluster deployment. You can push the changes to the SiteConfig CR and the PolicyGenTemplate CR simultaneously.

Additional resources

Signalling ZTP cluster deployment completion with validator inform policies

18.5.5. Monitoring managed cluster policy deployment progress

The ArgoCD pipeline uses PolicyGenTemplate CRs in Git to generate the RHACM policies and then sync them to the hub cluster. You can monitor the progress of the managed cluster policy synchronization after the assisted service installs OpenShift Container Platform on the managed cluster.

Prerequisites

You have installed the OpenShift CLI (oc).
You have logged in to the hub cluster as a user with cluster-admin privileges.

Procedure

The Topology Aware Lifecycle Manager (TALM) applies the configuration policies that are bound to the cluster.
After the cluster installation is complete and the cluster becomes Ready, a ClusterGroupUpgrade CR corresponding to this cluster, with a list of ordered policies defined by the ran.openshift.io/ztp-deploy-wave annotations, is automatically created by the TALM. The cluster’s policies are applied in the order listed in ClusterGroupUpgrade CR.
You can monitor the high-level progress of configuration policy reconciliation by using the following commands:
```
$ export CLUSTER=<clusterName>
```
```
$ oc get clustergroupupgrades -n ztp-install $CLUSTER -o jsonpath='{.status.conditions[-1:]}' | jq
```
Example output
```
{
  "lastTransitionTime": "2022-11-09T07:28:09Z",
  "message": "Remediating non-compliant policies",
  "reason": "InProgress",
  "status": "True",
  "type": "Progressing"
}
```

You can monitor the detailed cluster policy compliance status by using the RHACM dashboard or the command line.

To check policy compliance by using oc, run the following command:

$ oc get policies -n $CLUSTER

Example output

NAME                                                     REMEDIATION ACTION   COMPLIANCE STATE   AGE
ztp-common.common-config-policy                          inform               Compliant          3h42m
ztp-common.common-subscriptions-policy                   inform               NonCompliant       3h42m
ztp-group.group-du-sno-config-policy                     inform               NonCompliant       3h42m
ztp-group.group-du-sno-validator-du-policy               inform               NonCompliant       3h42m
ztp-install.example1-common-config-policy-pjz9s          enforce              Compliant          167m
ztp-install.example1-common-subscriptions-policy-zzd9k   enforce              NonCompliant       164m
ztp-site.example1-config-policy                          inform               NonCompliant       3h42m
ztp-site.example1-perf-policy                            inform               NonCompliant       3h42m

To check policy status from the RHACM web console, perform the following actions:
1. Click Governance → Find policies.
2. Click on a cluster policy to check it’s status.

When all of the cluster policies become compliant, GitOps ZTP installation and configuration for the cluster is complete. The ztp-done label is added to the cluster.

In the reference configuration, the final policy that becomes compliant is the one defined in the *-du-validator-policy policy. This policy, when compliant on a cluster, ensures that all cluster configuration, Operator installation, and Operator configuration is complete.

18.5.6. Validating the generation of configuration policy CRs

Policy custom resources (CRs) are generated in the same namespace as the PolicyGenTemplate from which they are created. The same troubleshooting flow applies to all policy CRs generated from a PolicyGenTemplate regardless of whether they are ztp-common, ztp-group, or ztp-site based, as shown using the following commands:

$ export NS=<namespace>

$ oc get policy -n $NS

The expected set of policy-wrapped CRs should be displayed.

If the policies failed synchronization, use the following troubleshooting steps.

Procedure

To display detailed information about the policies, run the following command:
```
$ oc describe -n openshift-gitops application policies
```

Check for Status: Conditions: to show the error logs. For example, setting an invalid sourceFile→fileName: generates the error shown below:

Status:
  Conditions:
    Last Transition Time:  2021-11-26T17:21:39Z
    Message:               rpc error: code = Unknown desc = `kustomize build /tmp/https___git.com/ran-sites/policies/ --enable-alpha-plugins` failed exit status 1: 2021/11/26 17:21:40 Error could not find test.yaml under source-crs/: no such file or directory Error: failure in plugin configured via /tmp/kust-plugin-config-52463179; exit status 1: exit status 1
    Type:  ComparisonError

Check for Status: Sync:. If there are log errors at Status: Conditions:, the Status: Sync: shows Unknown or Error:

Status:
  Sync:
    Compared To:
      Destination:
        Namespace:  policies-sub
        Server:     https://kubernetes.default.svc
      Source:
        Path:             policies
        Repo URL:         https://git.com/ran-sites/policies/.git
        Target Revision:  master
    Status:               Error

When Red Hat Advanced Cluster Management (RHACM) recognizes that policies apply to a ManagedCluster object, the policy CR objects are applied to the cluster namespace. Check to see if the policies were copied to the cluster namespace:

$ oc get policy -n $CLUSTER

Example output:

NAME                                         REMEDIATION ACTION   COMPLIANCE STATE   AGE
ztp-common.common-config-policy              inform               Compliant          13d
ztp-common.common-subscriptions-policy       inform               Compliant          13d
ztp-group.group-du-sno-config-policy         inform               Compliant          13d
Ztp-group.group-du-sno-validator-du-policy   inform               Compliant          13d
ztp-site.example-sno-config-policy           inform               Compliant          13d

RHACM copies all applicable policies into the cluster namespace. The copied policy names have the format: <policyGenTemplate.Namespace>.<policyGenTemplate.Name>-<policyName>.

Check the placement rule for any policies not copied to the cluster namespace. The matchSelector in the PlacementRule for those policies should match labels on the ManagedCluster object:
```
$ oc get placementrule -n $NS
```
Note the PlacementRule name appropriate for the missing policy, common, group, or site, using the following command:
```
$ oc get placementrule -n $NS <placementRuleName> -o yaml
```
- The status-decisions should include your cluster name.
- The key-value pair of the matchSelector in the spec must match the labels on your managed cluster.
Check the labels on the ManagedCluster object using the following command:
```
$ oc get ManagedCluster $CLUSTER -o jsonpath='{.metadata.labels}' | jq
```
Check to see which policies are compliant using the following command:
```
$ oc get policy -n $CLUSTER
```
If the Namespace, OperatorGroup, and Subscription policies are compliant but the Operator configuration policies are not, it is likely that the Operators did not install on the managed cluster. This causes the Operator configuration policies to fail to apply because the CRD is not yet applied to the spoke.

18.5.7. Restarting policy reconciliation

You can restart policy reconciliation when unexpected compliance issues occur, for example, when the ClusterGroupUpgrade custom resource (CR) has timed out.

Procedure

A ClusterGroupUpgrade CR is generated in the namespace ztp-install by the Topology Aware Lifecycle Manager after the managed cluster becomes Ready:
```
$ export CLUSTER=<clusterName>
```
```
$ oc get clustergroupupgrades -n ztp-install $CLUSTER
```
If there are unexpected issues and the policies fail to become complaint within the configured timeout (the default is 4 hours), the status of the ClusterGroupUpgrade CR shows UpgradeTimedOut:
```
$ oc get clustergroupupgrades -n ztp-install $CLUSTER -o jsonpath='{.status.conditions[?(@.type=="Ready")]}'
```
A ClusterGroupUpgrade CR in the UpgradeTimedOut state automatically restarts its policy reconciliation every hour. If you have changed your policies, you can start a retry immediately by deleting the existing ClusterGroupUpgrade CR. This triggers the automatic creation of a new ClusterGroupUpgrade CR that begins reconciling the policies immediately:
```
$ oc delete clustergroupupgrades -n ztp-install $CLUSTER
```

Note that when the ClusterGroupUpgrade CR completes with status UpgradeCompleted and the managed cluster has the label ztp-done applied, you can make additional configuration changes using PolicyGenTemplate. Deleting the existing ClusterGroupUpgrade CR will not make the TALM generate a new CR.

At this point, GitOps ZTP has completed its interaction with the cluster and any further interactions should be treated as an update and a new ClusterGroupUpgrade CR created for remediation of the policies.

Additional resources

For information about using Topology Aware Lifecycle Manager (TALM) to construct your own ClusterGroupUpgrade CR, see About the ClusterGroupUpgrade CR.

18.5.8. Changing applied managed cluster CRs using policies

You can remove content from a custom resource (CR) that is deployed in a managed cluster through a policy.

By default, all Policy CRs created from a PolicyGenTemplate CR have the complianceType field set to musthave. A musthave policy without the removed content is still compliant because the CR on the managed cluster has all the specified content. With this configuration, when you remove content from a CR, TALM removes the content from the policy but the content is not removed from the CR on the managed cluster.

With the complianceType field to mustonlyhave, the policy ensures that the CR on the cluster is an exact match of what is specified in the policy.

Prerequisites

You have installed the OpenShift CLI (oc).
You have logged in to the hub cluster as a user with cluster-admin privileges.
You have deployed a managed cluster from a hub cluster running RHACM.
You have installed Topology Aware Lifecycle Manager on the hub cluster.

Procedure

Remove the content that you no longer need from the affected CRs. In this example, the disableDrain: false line was removed from the SriovOperatorConfig CR.

Example CR

apiVersion: sriovnetwork.openshift.io/v1
kind: SriovOperatorConfig
metadata:
  name: default
  namespace: openshift-sriov-network-operator
spec:
  configDaemonNodeSelector:
    "node-role.kubernetes.io/$mcp": ""
  disableDrain: true
  enableInjector: true
  enableOperatorWebhook: true

Change the complianceType of the affected policies to mustonlyhave in the group-du-sno-ranGen.yaml file.
Example YAML
```
# ...
- fileName: SriovOperatorConfig.yaml
  policyName: "config-policy"
  complianceType: mustonlyhave
# ...
```

Create a ClusterGroupUpdates CR and specify the clusters that must receive the CR changes::

Example ClusterGroupUpdates CR

apiVersion: ran.openshift.io/v1alpha1
kind: ClusterGroupUpgrade
metadata:
  name: cgu-remove
  namespace: default
spec:
  managedPolicies:
    - ztp-group.group-du-sno-config-policy
  enable: false
  clusters:
  - spoke1
  - spoke2
  remediationStrategy:
    maxConcurrency: 2
    timeout: 240
  batchTimeoutAction:

Create the ClusterGroupUpgrade CR by running the following command:
```
$ oc create -f cgu-remove.yaml
```
When you are ready to apply the changes, for example, during an appropriate maintenance window, change the value of the spec.enable field to true by running the following command:
```
$ oc --namespace=default patch clustergroupupgrade.ran.openshift.io/cgu-remove \
--patch '{"spec":{"enable":true}}' --type=merge
```

Verification

Check the status of the policies by running the following command:

$ oc get <kind> <changed_cr_name>

Example output

NAMESPACE   NAME                                                   REMEDIATION ACTION   COMPLIANCE STATE   AGE
default     cgu-ztp-group.group-du-sno-config-policy               enforce                                 17m
default     ztp-group.group-du-sno-config-policy                   inform               NonCompliant       15h

When the COMPLIANCE STATE of the policy is Compliant, it means that the CR is updated and the unwanted content is removed.

Check that the policies are removed from the targeted clusters by running the following command on the managed clusters:
```
$ oc get <kind> <changed_cr_name>
```
If there are no results, the CR is removed from the managed cluster.

18.5.9. Indication of done for GitOps ZTP installations

GitOps Zero Touch Provisioning (ZTP) simplifies the process of checking the GitOps ZTP installation status for a cluster. The GitOps ZTP status moves through three phases: cluster installation, cluster configuration, and GitOps ZTP done.

Cluster installation phase

The cluster installation phase is shown by the ManagedClusterJoined and ManagedClusterAvailable conditions in the ManagedCluster CR . If the ManagedCluster CR does not have these conditions, or the condition is set to False, the cluster is still in the installation phase. Additional details about installation are available from the AgentClusterInstall and ClusterDeployment CRs. For more information, see "Troubleshooting GitOps ZTP".

Cluster configuration phase

The cluster configuration phase is shown by a ztp-running label applied the ManagedCluster CR for the cluster.

GitOps ZTP done

Cluster installation and configuration is complete in the GitOps ZTP done phase. This is shown by the removal of the ztp-running label and addition of the ztp-done label to the ManagedCluster CR. The ztp-done label shows that the configuration has been applied and the baseline DU configuration has completed cluster tuning.

The transition to the GitOps ZTP done state is conditional on the compliant state of a Red Hat Advanced Cluster Management (RHACM) validator inform policy. This policy captures the existing criteria for a completed installation and validates that it moves to a compliant state only when GitOps ZTP provisioning of the managed cluster is complete.

The validator inform policy ensures the configuration of the cluster is fully applied and Operators have completed their initialization. The policy validates the following:

The target MachineConfigPool contains the expected entries and has finished updating. All nodes are available and not degraded.
The SR-IOV Operator has completed initialization as indicated by at least one SriovNetworkNodeState with syncStatus: Succeeded.
The PTP Operator daemon set exists.

18.6. Manually installing a single-node OpenShift cluster with ZTP

You can deploy a managed single-node OpenShift cluster by using Red Hat Advanced Cluster Management (RHACM) and the assisted service.

Note

If you are creating multiple managed clusters, use the SiteConfig method described in Deploying far edge sites with ZTP.

Important

The target bare-metal host must meet the networking, firmware, and hardware requirements listed in Recommended cluster configuration for vDU application workloads.

18.6.1. Generating GitOps ZTP installation and configuration CRs manually

Use the generator entrypoint for the ztp-site-generate container to generate the site installation and configuration custom resource (CRs) for a cluster based on SiteConfig and PolicyGenTemplate CRs.

Prerequisites

You have installed the OpenShift CLI (oc).
You have logged in to the hub cluster as a user with cluster-admin privileges.

Procedure

Create an output folder by running the following command:
```
$ mkdir -p ./out
```

Export the argocd directory from the ztp-site-generate container image:

$ podman run --log-driver=none --rm registry.redhat.io/openshift4/ztp-site-generate-rhel8:v4.14 extract /home/ztp --tar | tar x -C ./out

The ./out directory has the reference PolicyGenTemplate and SiteConfig CRs in the out/argocd/example/ folder.

Example output

out
 └── argocd
      └── example
           ├── policygentemplates
           │     ├── common-ranGen.yaml
           │     ├── example-sno-site.yaml
           │     ├── group-du-sno-ranGen.yaml
           │     ├── group-du-sno-validator-ranGen.yaml
           │     ├── kustomization.yaml
           │     └── ns.yaml
           └── siteconfig
                  ├── example-sno.yaml
                  ├── KlusterletAddonConfigOverride.yaml
                  └── kustomization.yaml

Create an output folder for the site installation CRs:
```
$ mkdir -p ./site-install
```

Modify the example SiteConfig CR for the cluster type that you want to install. Copy example-sno.yaml to site-1-sno.yaml and modify the CR to match the details of the site and bare-metal host that you want to install, for example:

# example-node1-bmh-secret & assisted-deployment-pull-secret need to be created under same namespace example-sno
---
apiVersion: ran.openshift.io/v1
kind: SiteConfig
metadata:
  name: "example-sno"
  namespace: "example-sno"
spec:
  baseDomain: "example.com"
  pullSecretRef:
    name: "assisted-deployment-pull-secret"
  clusterImageSetNameRef: "openshift-4.10"
  sshPublicKey: "ssh-rsa AAAA..."
  clusters:
  - clusterName: "example-sno"
    networkType: "OVNKubernetes"
    # installConfigOverrides is a generic way of passing install-config
    # parameters through the siteConfig.  The 'capabilities' field configures
    # the composable openshift feature.  In this 'capabilities' setting, we
    # remove all but the marketplace component from the optional set of
    # components.
    # Notes:
    # - OperatorLifecycleManager is needed for 4.15 and later
    # - NodeTuning is needed for 4.13 and later, not for 4.12 and earlier
    installConfigOverrides: |
      {
        "capabilities": {
          "baselineCapabilitySet": "None",
          "additionalEnabledCapabilities": [
            "NodeTuning",
            "OperatorLifecycleManager"
          ]
        }
      }
    # It is strongly recommended to include crun manifests as part of the additional install-time manifests for 4.13+.
    # The crun manifests can be obtained from source-crs/optional-extra-manifest/ and added to the git repo ie.sno-extra-manifest.
    # extraManifestPath: sno-extra-manifest
    clusterLabels:
      # These example cluster labels correspond to the bindingRules in the PolicyGenTemplate examples
      du-profile: "latest"
      # These example cluster labels correspond to the bindingRules in the PolicyGenTemplate examples in ../policygentemplates:
      # ../policygentemplates/common-ranGen.yaml will apply to all clusters with 'common: true'
      common: true
      # ../policygentemplates/group-du-sno-ranGen.yaml will apply to all clusters with 'group-du-sno: ""'
      group-du-sno: ""
      # ../policygentemplates/example-sno-site.yaml will apply to all clusters with 'sites: "example-sno"'
      # Normally this should match or contain the cluster name so it only applies to a single cluster
      sites : "example-sno"
    clusterNetwork:
      - cidr: 1001:1::/48
        hostPrefix: 64
    machineNetwork:
      - cidr: 1111:2222:3333:4444::/64
    serviceNetwork:
      - 1001:2::/112
    additionalNTPSources:
      - 1111:2222:3333:4444::2
    # Initiates the cluster for workload partitioning. Setting specific reserved/isolated CPUSets is done via PolicyTemplate
    # please see Workload Partitioning Feature for a complete guide.
    cpuPartitioningMode: AllNodes
    # Optionally; This can be used to override the KlusterletAddonConfig that is created for this cluster:
    #crTemplates:
    #  KlusterletAddonConfig: "KlusterletAddonConfigOverride.yaml"
    nodes:
      - hostName: "example-node1.example.com"
        role: "master"
        # Optionally; This can be used to configure desired BIOS setting on a host:
        #biosConfigRef:
        #  filePath: "example-hw.profile"
        bmcAddress: "idrac-virtualmedia+https://[1111:2222:3333:4444::bbbb:1]/redfish/v1/Systems/System.Embedded.1"
        bmcCredentialsName:
          name: "example-node1-bmh-secret"
        bootMACAddress: "AA:BB:CC:DD:EE:11"
        # Use UEFISecureBoot to enable secure boot
        bootMode: "UEFI"
        rootDeviceHints:
          deviceName: "/dev/disk/by-path/pci-0000:01:00.0-scsi-0:2:0:0"
        # disk partition at `/var/lib/containers` with ignitionConfigOverride. Some values must be updated. See DiskPartitionContainer.md for more details
        ignitionConfigOverride: |
           {
            "ignition": {
              "version": "3.2.0"
            },
            "storage": {
              "disks": [
                {
                  "device": "/dev/disk/by-path/pci-0000:01:00.0-scsi-0:2:0:0",
                  "partitions": [
                    {
                     "label": "var-lib-containers",
                     "sizeMiB": 0,
                     "startMiB": 250000
                  }
              ],
              "wipeTable": false
             }
           ],
            "filesystems": [
              {
               "device": "/dev/disk/by-partlabel/var-lib-containers",
               "format": "xfs",
               "mountOptions": [
                 "defaults",
                 "prjquota"
                ],
                "path": "/var/lib/containers",
                "wipeFilesystem": true
               }
             ]
           },
           "systemd": {
             "units": [
               {
                "contents": "# Generated by Butane\n[Unit]\nRequires=systemd-fsck@dev-disk-by\\x2dpartlabel-var\\x2dlib\\x2dcontainers.service\nAfter=systemd-fsck@dev-disk-by\\x2dpartlabel-var\\x2dlib\\x2dcontainers.service\n\n[Mount]\nWhere=/var/lib/containers\nWhat=/dev/disk/by-partlabel/var-lib-containers\nType=xfs\nOptions=defaults,prjquota\n\n[Install]\nRequiredBy=local-fs.target",
                "enabled": true,
                "name": "var-lib-containers.mount"
               }
              ]
            }
           }
        nodeNetwork:
          interfaces:
            - name: eno1
              macAddress: "AA:BB:CC:DD:EE:11"
          config:
            interfaces:
              - name: eno1
                type: ethernet
                state: up
                ipv4:
                  enabled: false
                ipv6:
                  enabled: true
                  address:
                  # For SNO sites with static IP addresses, the node-specific,
                  # API and Ingress IPs should all be the same and configured on
                  # the interface
                  - ip: 1111:2222:3333:4444::aaaa:1
                    prefix-length: 64
            dns-resolver:
              config:
                search:
                - example.com
                server:
                - 1111:2222:3333:4444::2
            routes:
              config:
              - destination: ::/0
                next-hop-interface: eno1
                next-hop-address: 1111:2222:3333:4444::1
                table-id: 254

Note

Once you have extracted reference CR configuration files from the out/extra-manifest directory of the ztp-site-generate container, you can use extraManifests.searchPaths to include the path to the git directory containing those files. This allows the GitOps ZTP pipeline to apply those CR files during cluster installation. If you configure a searchPaths directory, the GitOps ZTP pipeline does not fetch manifests from the ztp-site-generate container during site installation.

Generate the Day 0 installation CRs by processing the modified SiteConfig CR site-1-sno.yaml by running the following command:

$ podman run -it --rm -v `pwd`/out/argocd/example/siteconfig:/resources:Z -v `pwd`/site-install:/output:Z,U registry.redhat.io/openshift4/ztp-site-generate-rhel8:v4.14 generator install site-1-sno.yaml /output

Example output

site-install
└── site-1-sno
    ├── site-1_agentclusterinstall_example-sno.yaml
    ├── site-1-sno_baremetalhost_example-node1.example.com.yaml
    ├── site-1-sno_clusterdeployment_example-sno.yaml
    ├── site-1-sno_configmap_example-sno.yaml
    ├── site-1-sno_infraenv_example-sno.yaml
    ├── site-1-sno_klusterletaddonconfig_example-sno.yaml
    ├── site-1-sno_machineconfig_02-master-workload-partitioning.yaml
    ├── site-1-sno_machineconfig_predefined-extra-manifests-master.yaml
    ├── site-1-sno_machineconfig_predefined-extra-manifests-worker.yaml
    ├── site-1-sno_managedcluster_example-sno.yaml
    ├── site-1-sno_namespace_example-sno.yaml
    └── site-1-sno_nmstateconfig_example-node1.example.com.yaml

Optional: Generate just the Day 0 MachineConfig installation CRs for a particular cluster type by processing the reference SiteConfig CR with the -E option. For example, run the following commands:

Create an output folder for the MachineConfig CRs:
```
$ mkdir -p ./site-machineconfig
```

Generate the MachineConfig installation CRs:

$ podman run -it --rm -v `pwd`/out/argocd/example/siteconfig:/resources:Z -v `pwd`/site-machineconfig:/output:Z,U registry.redhat.io/openshift4/ztp-site-generate-rhel8:v4.14 generator install -E site-1-sno.yaml /output

Example output

site-machineconfig
└── site-1-sno
    ├── site-1-sno_machineconfig_02-master-workload-partitioning.yaml
    ├── site-1-sno_machineconfig_predefined-extra-manifests-master.yaml
    └── site-1-sno_machineconfig_predefined-extra-manifests-worker.yaml

Generate and export the Day 2 configuration CRs using the reference PolicyGenTemplate CRs from the previous step. Run the following commands:

Create an output folder for the Day 2 CRs:
```
$ mkdir -p ./ref
```

Generate and export the Day 2 configuration CRs:

$ podman run -it --rm -v `pwd`/out/argocd/example/policygentemplates:/resources:Z -v `pwd`/ref:/output:Z,U registry.redhat.io/openshift4/ztp-site-generate-rhel8:v4.14 generator config -N . /output

The command generates example group and site-specific PolicyGenTemplate CRs for single-node OpenShift, three-node clusters, and standard clusters in the ./ref folder.

Example output

ref
 └── customResource
      ├── common
      ├── example-multinode-site
      ├── example-sno
      ├── group-du-3node
      ├── group-du-3node-validator
      │    └── Multiple-validatorCRs
      ├── group-du-sno
      ├── group-du-sno-validator
      ├── group-du-standard
      └── group-du-standard-validator
           └── Multiple-validatorCRs

Use the generated CRs as the basis for the CRs that you use to install the cluster. You apply the installation CRs to the hub cluster as described in "Installing a single managed cluster". The configuration CRs can be applied to the cluster after cluster installation is complete.

Verification

Verify that the custom roles and labels are applied after the node is deployed:
```
$ oc describe node example-node.example.com
```

Example output

Name:   example-node.example.com
Roles:  control-plane,example-label,master,worker
Labels: beta.kubernetes.io/arch=amd64
        beta.kubernetes.io/os=linux
        custom-label/parameter1=true
        kubernetes.io/arch=amd64
        kubernetes.io/hostname=cnfdf03.telco5gran.eng.rdu2.redhat.com
        kubernetes.io/os=linux
        node-role.kubernetes.io/control-plane=
        node-role.kubernetes.io/example-label= 1
        node-role.kubernetes.io/master=
        node-role.kubernetes.io/worker=
        node.openshift.io/os_id=rhcos

1: The custom label is applied to the node.

Additional resources

Workload partitioning
BMC addressing
About root device hints
Single-node OpenShift SiteConfig CR installation reference

18.6.2. Creating the managed bare-metal host secrets

Note

The secrets are referenced from the SiteConfig CR by name. The namespace must match the SiteConfig namespace.

Procedure

Create a YAML secret file containing credentials for the host Baseboard Management Controller (BMC) and a pull secret required for installing OpenShift and all add-on cluster Operators:
1. Save the following YAML as the file example-sno-secret.yaml:
```
apiVersion: v1
kind: Secret
metadata:
  name: example-sno-bmc-secret
  namespace: example-sno 1
data: 2
  password: <base64_password>
  username: <base64_username>
type: Opaque
---
apiVersion: v1
kind: Secret
metadata:
  name: pull-secret
  namespace: example-sno  3
data:
  .dockerconfigjson: <pull_secret> 4
type: kubernetes.io/dockerconfigjson
```
  1
  Must match the namespace configured in the related SiteConfig CR
  2
  Base64-encoded values for password and username
  3
  Must match the namespace configured in the related SiteConfig CR
  4
  Base64-encoded pull secret
Add the relative path to example-sno-secret.yaml to the kustomization.yaml file that you use to install the cluster.

18.6.3. Configuring Discovery ISO kernel arguments for manual installations using GitOps ZTP

Note

In OpenShift Container Platform 4.14, you can only add kernel arguments. You can not replace or delete kernel arguments.

Prerequisites

You have installed the OpenShift CLI (oc).
You have logged in to the hub cluster as a user with cluster-admin privileges.
You have manually generated the installation and configuration custom resources (CRs).

Procedure

Edit the spec.kernelArguments specification in the InfraEnv CR to configure kernel arguments:

apiVersion: agent-install.openshift.io/v1beta1
kind: InfraEnv
metadata:
  name: <cluster_name>
  namespace: <cluster_name>
spec:
  kernelArguments:
    - operation: append 1
      value: audit=0 2
    - operation: append
      value: trace=1
  clusterRef:
    name: <cluster_name>
    namespace: <cluster_name>
  pullSecretRef:
    name: pull-secret

1: Specify the append operation to add a kernel argument.
2: Specify the kernel argument you want to configure. This example configures the audit kernel argument and the trace kernel argument.

Note

The SiteConfig CR generates the InfraEnv resource as part of the day-0 installation CRs.

Verification

Begin an SSH session with the target host:

$ ssh -i /path/to/privatekey core@<host_name>

View the system’s kernel arguments by using the following command:
```
$ cat /proc/cmdline
```

18.6.4. Installing a single managed cluster

You can manually deploy a single managed cluster using the assisted service and Red Hat Advanced Cluster Management (RHACM).

Prerequisites

You have installed the OpenShift CLI (oc).
You have logged in to the hub cluster as a user with cluster-admin privileges.
You have created the baseboard management controller (BMC) Secret and the image pull-secret Secret custom resources (CRs). See "Creating the managed bare-metal host secrets" for details.
Your target bare-metal host meets the networking and hardware requirements for managed clusters.

Procedure

Create a ClusterImageSet for each specific cluster version to be deployed, for example clusterImageSet-4.14.yaml. A ClusterImageSet has the following format:
```
apiVersion: hive.openshift.io/v1
kind: ClusterImageSet
metadata:
  name: openshift-4.14.0 1
spec:
   releaseImage: quay.io/openshift-release-dev/ocp-release:4.14.0-x86_64 2
```
1
The descriptive version that you want to deploy.
2
Specifies the releaseImage to deploy and determines the operating system image version. The discovery ISO is based on the image version as set by releaseImage, or the latest version if the exact version is unavailable.
Apply the clusterImageSet CR:
```
$ oc apply -f clusterImageSet-4.14.yaml
```

Create the Namespace CR in the cluster-namespace.yaml file:

apiVersion: v1
kind: Namespace
metadata:
     name: <cluster_name> 1
     labels:
        name: <cluster_name> 2

1 2: The name of the managed cluster to provision.

Apply the Namespace CR by running the following command:
```
$ oc apply -f cluster-namespace.yaml
```
Apply the generated day-0 CRs that you extracted from the ztp-site-generate container and customized to meet your requirements:
```
$ oc apply -R ./site-install/site-sno-1
```

Additional resources

Connectivity prerequisites for managed cluster networks
Deploying LVM Storage on single-node OpenShift clusters
Configuring LVM Storage using PolicyGenTemplate CRs

18.6.5. Monitoring the managed cluster installation status

Ensure that cluster provisioning was successful by checking the cluster status.

Prerequisites

All of the custom resources have been configured and provisioned, and the Agent custom resource is created on the hub for the managed cluster.

Procedure

Check the status of the managed cluster:
```
$ oc get managedcluster
```
True indicates the managed cluster is ready.
Check the agent status:
```
$ oc get agent -n <cluster_name>
```
Use the describe command to provide an in-depth description of the agent’s condition. Statuses to be aware of include BackendError, InputError, ValidationsFailing, InstallationFailed, and AgentIsConnected. These statuses are relevant to the Agent and AgentClusterInstall custom resources.
```
$ oc describe agent -n <cluster_name>
```

Check the cluster provisioning status:

$ oc get agentclusterinstall -n <cluster_name>

Use the describe command to provide an in-depth description of the cluster provisioning status:
```
$ oc describe agentclusterinstall -n <cluster_name>
```
Check the status of the managed cluster’s add-on services:
```
$ oc get managedclusteraddon -n <cluster_name>
```

Retrieve the authentication information of the kubeconfig file for the managed cluster:

$ oc get secret -n <cluster_name> <cluster_name>-admin-kubeconfig -o jsonpath={.data.kubeconfig} | base64 -d > <directory>/<cluster_name>-kubeconfig

18.6.6. Troubleshooting the managed cluster

Use this procedure to diagnose any installation issues that might occur with the managed cluster.

Procedure

Check the status of the managed cluster:
```
$ oc get managedcluster
```
Example output
```
NAME            HUB ACCEPTED   MANAGED CLUSTER URLS   JOINED   AVAILABLE   AGE
SNO-cluster     true                                   True     True      2d19h
```
If the status in the AVAILABLE column is True, the managed cluster is being managed by the hub.
If the status in the AVAILABLE column is Unknown, the managed cluster is not being managed by the hub. Use the following steps to continue checking to get more information.

Check the AgentClusterInstall install status:

$ oc get clusterdeployment -n <cluster_name>

Example output

NAME        PLATFORM            REGION   CLUSTERTYPE   INSTALLED    INFRAID    VERSION  POWERSTATE AGE
Sno0026    agent-baremetal                               false                          Initialized
2d14h

If the status in the INSTALLED column is false, the installation was unsuccessful.

If the installation failed, enter the following command to review the status of the AgentClusterInstall resource:
```
$ oc describe agentclusterinstall -n <cluster_name> <cluster_name>
```
Resolve the errors and reset the cluster:
1. Remove the cluster’s managed cluster resource:
```
$ oc delete managedcluster <cluster_name>
```
2. Remove the cluster’s namespace:
```
$ oc delete namespace <cluster_name>
```
  This deletes all of the namespace-scoped custom resources created for this cluster. You must wait for the ManagedCluster CR deletion to complete before proceeding.
3. Recreate the custom resources for the managed cluster.

18.6.7. RHACM generated cluster installation CRs reference

Red Hat Advanced Cluster Management (RHACM) supports deploying OpenShift Container Platform on single-node clusters, three-node clusters, and standard clusters with a specific set of installation custom resources (CRs) that you generate using SiteConfig CRs for each site.

Note

Every managed cluster has its own namespace, and all of the installation CRs except for ManagedCluster and ClusterImageSet are under that namespace. ManagedCluster and ClusterImageSet are cluster-scoped, not namespace-scoped. The namespace and the CR names match the cluster name.

The following table lists the installation CRs that are automatically applied by the RHACM assisted service when it installs clusters using the SiteConfig CRs that you configure.

Table 18.10. Cluster installation CRs generated by RHACM
CR	Description	Usage
`BareMetalHost`	Contains the connection information for the Baseboard Management Controller (BMC) of the target bare-metal host.	Provides access to the BMC to load and start the discovery image on the target server by using the Redfish protocol.
`InfraEnv`	Contains information for installing OpenShift Container Platform on the target bare-metal host.	Used with `ClusterDeployment` to generate the discovery ISO for the managed cluster.
`AgentClusterInstall`	Specifies details of the managed cluster configuration such as networking and the number of control plane nodes. Displays the cluster `kubeconfig` and credentials when the installation is complete.	Specifies the managed cluster configuration information and provides status during the installation of the cluster.
`ClusterDeployment`	References the `AgentClusterInstall` CR to use.	Used with `InfraEnv` to generate the discovery ISO for the managed cluster.
`NMStateConfig`	Provides network configuration information such as `MAC` address to `IP` mapping, DNS server, default route, and other network settings.	Sets up a static IP address for the managed cluster’s Kube API server.
`Agent`	Contains hardware information about the target bare-metal host.	Created automatically on the hub when the target machine’s discovery image boots.
`ManagedCluster`	When a cluster is managed by the hub, it must be imported and known. This Kubernetes object provides that interface.	The hub uses this resource to manage and show the status of managed clusters.
`KlusterletAddonConfig`	Contains the list of services provided by the hub to be deployed to the `ManagedCluster` resource.	Tells the hub which addon services to deploy to the `ManagedCluster` resource.
`Namespace`	Logical space for `ManagedCluster` resources existing on the hub. Unique per site.	Propagates resources to the `ManagedCluster`.
`Secret`	Two CRs are created: `BMC Secret` and `Image Pull Secret`.	`BMC Secret` authenticates into the target bare-metal host using its username and password. `Image Pull Secret` contains authentication information for the OpenShift Container Platform image installed on the target bare-metal host.
`ClusterImageSet`	Contains OpenShift Container Platform image information such as the repository and image name.	Passed into resources to provide OpenShift Container Platform images.

18.7. Recommended single-node OpenShift cluster configuration for vDU application workloads

Use the following reference information to understand the single-node OpenShift configurations required to deploy virtual distributed unit (vDU) applications in the cluster. Configurations include cluster optimizations for high performance workloads, enabling workload partitioning, and minimizing the number of reboots required postinstallation.

Additional resources

To deploy a single cluster by hand, see Manually installing a single-node OpenShift cluster with GitOps ZTP.
To deploy a fleet of clusters using GitOps Zero Touch Provisioning (ZTP), see Deploying far edge sites with GitOps ZTP.

18.7.1. Running low latency applications on OpenShift Container Platform

OpenShift Container Platform enables low latency processing for applications running on commercial off-the-shelf (COTS) hardware by using several technologies and specialized hardware devices:

Real-time kernel for RHCOS: Ensures workloads are handled with a high degree of process determinism.
CPU isolation: Avoids CPU scheduling delays and ensures CPU capacity is available consistently.
NUMA-aware topology management: Aligns memory and huge pages with CPU and PCI devices to pin guaranteed container memory and huge pages to the non-uniform memory access (NUMA) node. Pod resources for all Quality of Service (QoS) classes stay on the same NUMA node. This decreases latency and improves performance of the node.
Huge pages memory management: Using huge page sizes improves system performance by reducing the amount of system resources required to access page tables.
Precision timing synchronization using PTP: Allows synchronization between nodes in the network with sub-microsecond accuracy.

18.7.2. Recommended cluster host requirements for vDU application workloads

Running vDU application workloads requires a bare-metal host with sufficient resources to run OpenShift Container Platform services and production workloads.

Table 18.11. Minimum resource requirements
Profile	vCPU	Memory	Storage
Minimum	4 to 8 vCPU	32GB of RAM	120GB

Note

One vCPU equals one physical core. However, if you enable simultaneous multithreading (SMT), or Hyper-Threading, use the following formula to calculate the number of vCPUs that represent one physical core:

(threads per core × cores) × sockets = vCPUs

Important

The server must have a Baseboard Management Controller (BMC) when booting with virtual media.

18.7.3. Configuring host firmware for low latency and high performance

Bare-metal hosts require the firmware to be configured before the host can be provisioned. The firmware configuration is dependent on the specific hardware and the particular requirements of your installation.

Procedure

Set the UEFI/BIOS Boot Mode to UEFI.
In the host boot sequence order, set Hard drive first.

Apply the specific firmware configuration for your hardware. The following table describes a representative firmware configuration for an Intel Xeon Skylake or Intel Cascade Lake server, based on the Intel FlexRAN 4G and 5G baseband PHY reference design.

Important

The exact firmware configuration depends on your specific hardware and network requirements. The following sample configuration is for illustrative purposes only.

Table 18.12. Sample firmware configuration for an Intel Xeon Skylake or Cascade Lake server
Firmware setting	Configuration
CPU Power and Performance Policy	Performance
Uncore Frequency Scaling	Disabled
Performance P-limit	Disabled
Enhanced Intel SpeedStep ® Tech	Enabled
Intel Configurable TDP	Enabled
Configurable TDP Level	Level 2
Intel® Turbo Boost Technology	Enabled
Energy Efficient Turbo	Disabled
Hardware P-States	Disabled
Package C-State	C0/C1 state
C1E	Disabled
Processor C6	Disabled

Note

Enable global SR-IOV and VT-d settings in the firmware for the host. These settings are relevant to bare-metal environments.

18.7.4. Connectivity prerequisites for managed cluster networks

Before you can install and provision a managed cluster with the GitOps Zero Touch Provisioning (ZTP) pipeline, the managed cluster host must meet the following networking prerequisites:

There must be bi-directional connectivity between the GitOps ZTP container in the hub cluster and the Baseboard Management Controller (BMC) of the target bare-metal host.
The managed cluster must be able to resolve and reach the API hostname of the hub hostname and *.apps hostname. Here is an example of the API hostname of the hub and *.apps hostname:
- api.hub-cluster.internal.domain.com
- console-openshift-console.apps.hub-cluster.internal.domain.com
The hub cluster must be able to resolve and reach the API and *.apps hostname of the managed cluster. Here is an example of the API hostname of the managed cluster and *.apps hostname:
- api.sno-managed-cluster-1.internal.domain.com
- console-openshift-console.apps.sno-managed-cluster-1.internal.domain.com

18.7.5. Workload partitioning in single-node OpenShift with GitOps ZTP

Workload partitioning configures OpenShift Container Platform services, cluster management workloads, and infrastructure pods to run on a reserved number of host CPUs.

To configure workload partitioning with GitOps Zero Touch Provisioning (ZTP), you configure a cpuPartitioningMode field in the SiteConfig custom resource (CR) that you use to install the cluster and you apply a PerformanceProfile CR that configures the isolated and reserved CPUs on the host.

Configuring the SiteConfig CR enables workload partitioning at cluster installation time and applying the PerformanceProfile CR configures the specific allocation of CPUs to reserved and isolated sets. Both of these steps happen at different points during cluster provisioning.

Note

Configuring workload partitioning by using the cpuPartitioningMode field in the SiteConfig CR is a Tech Preview feature in OpenShift Container Platform 4.13.

Alternatively, you can specify cluster management CPU resources with the cpuset field of the SiteConfig custom resource (CR) and the reserved field of the group PolicyGenTemplate CR. The GitOps ZTP pipeline uses these values to populate the required fields in the workload partitioning MachineConfig CR (cpuset) and the PerformanceProfile CR (reserved) that configure the single-node OpenShift cluster. This method is a General Availability feature in OpenShift Container Platform 4.14.

The workload partitioning configuration pins the OpenShift Container Platform infrastructure pods to the reserved CPU set. Platform services such as systemd, CRI-O, and kubelet run on the reserved CPU set. The isolated CPU sets are exclusively allocated to your container workloads. Isolating CPUs ensures that the workload has guaranteed access to the specified CPUs without contention from other applications running on the same node. All CPUs that are not isolated should be reserved.

Important

Ensure that reserved and isolated CPU sets do not overlap with each other.

Additional resources

For the recommended single-node OpenShift workload partitioning configuration, see Workload partitioning.

18.7.6. Recommended cluster install manifests

The ZTP pipeline applies the following custom resources (CRs) during cluster installation. These configuration CRs ensure that the cluster meets the feature and performance requirements necessary for running a vDU application.

Note

When using the GitOps ZTP plugin and SiteConfig CRs for cluster deployment, the following MachineConfig CRs are included by default.

Use the SiteConfig extraManifests filter to alter the CRs that are included by default. For more information, see Advanced managed cluster configuration with SiteConfig CRs.

18.7.6.1. Workload partitioning

Single-node OpenShift clusters that run DU workloads require workload partitioning. This limits the cores allowed to run platform services, maximizing the CPU core for application payloads.

Note

Workload partitioning can be enabled during cluster installation only. You cannot disable workload partitioning postinstallation. You can however change the set of CPUs assigned to the isolated and reserved sets through the PerformanceProfile CR. Changes to CPU settings cause the node to reboot.

Upgrading from OpenShift Container Platform 4.12 to 4.13+

When transitioning to using cpuPartitioningMode for enabling workload partitioning, remove the workload partitioning MachineConfig CRs from the /extra-manifest folder that you use to provision the cluster.

Recommended SiteConfig CR configuration for workload partitioning

apiVersion: ran.openshift.io/v1
kind: SiteConfig
metadata:
  name: "<site_name>"
  namespace: "<site_name>"
spec:
  baseDomain: "example.com"
  cpuPartitioningMode: AllNodes 1

1: Set the cpuPartitioningMode field to AllNodes to configure workload partitioning for all nodes in the cluster.

Verification

Check that the applications and cluster system CPU pinning is correct. Run the following commands:

Open a remote shell prompt to the managed cluster:
```
$ oc debug node/example-sno-1
```

Check that the OpenShift infrastructure applications CPU pinning is correct:

sh-4.4# pgrep ovn | while read i; do taskset -cp $i; done

Example output

pid 8481's current affinity list: 0-1,52-53
pid 8726's current affinity list: 0-1,52-53
pid 9088's current affinity list: 0-1,52-53
pid 9945's current affinity list: 0-1,52-53
pid 10387's current affinity list: 0-1,52-53
pid 12123's current affinity list: 0-1,52-53
pid 13313's current affinity list: 0-1,52-53

Check that the system applications CPU pinning is correct:

sh-4.4# pgrep systemd | while read i; do taskset -cp $i; done

Example output

pid 1's current affinity list: 0-1,52-53
pid 938's current affinity list: 0-1,52-53
pid 962's current affinity list: 0-1,52-53
pid 1197's current affinity list: 0-1,52-53

18.7.6.2. Reduced platform management footprint

To reduce the overall management footprint of the platform, a MachineConfig custom resource (CR) is required that places all Kubernetes-specific mount points in a new namespace separate from the host operating system. The following base64-encoded example MachineConfig CR illustrates this configuration.

Recommended container mount namespace configuration (01-container-mount-ns-and-kubelet-conf-master.yaml)

apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: master
  name: container-mount-namespace-and-kubelet-conf-master
spec:
  config:
    ignition:
      version: 3.2.0
    storage:
      files:
        - contents:
            source: data:text/plain;charset=utf-8;base64,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
          mode: 493
          path: /usr/local/bin/extractExecStart
        - contents:
            source: data:text/plain;charset=utf-8;base64,IyEvYmluL2Jhc2gKbnNlbnRlciAtLW1vdW50PS9ydW4vY29udGFpbmVyLW1vdW50LW5hbWVzcGFjZS9tbnQgIiRAIgo=
          mode: 493
          path: /usr/local/bin/nsenterCmns
    systemd:
      units:
        - contents: |
            [Unit]
            Description=Manages a mount namespace that both kubelet and crio can use to share their container-specific mounts

            [Service]
            Type=oneshot
            RemainAfterExit=yes
            RuntimeDirectory=container-mount-namespace
            Environment=RUNTIME_DIRECTORY=%t/container-mount-namespace
            Environment=BIND_POINT=%t/container-mount-namespace/mnt
            ExecStartPre=bash -c "findmnt ${RUNTIME_DIRECTORY} || mount --make-unbindable --bind ${RUNTIME_DIRECTORY} ${RUNTIME_DIRECTORY}"
            ExecStartPre=touch ${BIND_POINT}
            ExecStart=unshare --mount=${BIND_POINT} --propagation slave mount --make-rshared /
            ExecStop=umount -R ${RUNTIME_DIRECTORY}
          name: container-mount-namespace.service
        - dropins:
            - contents: |
                [Unit]
                Wants=container-mount-namespace.service
                After=container-mount-namespace.service

                [Service]
                ExecStartPre=/usr/local/bin/extractExecStart %n /%t/%N-execstart.env ORIG_EXECSTART
                EnvironmentFile=-/%t/%N-execstart.env
                ExecStart=
                ExecStart=bash -c "nsenter --mount=%t/container-mount-namespace/mnt \
                    ${ORIG_EXECSTART}"
              name: 90-container-mount-namespace.conf
          name: crio.service
        - dropins:
            - contents: |
                [Unit]
                Wants=container-mount-namespace.service
                After=container-mount-namespace.service

                [Service]
                ExecStartPre=/usr/local/bin/extractExecStart %n /%t/%N-execstart.env ORIG_EXECSTART
                EnvironmentFile=-/%t/%N-execstart.env
                ExecStart=
                ExecStart=bash -c "nsenter --mount=%t/container-mount-namespace/mnt \
                    ${ORIG_EXECSTART} --housekeeping-interval=30s"
              name: 90-container-mount-namespace.conf
            - contents: |
                [Service]
                Environment="OPENSHIFT_MAX_HOUSEKEEPING_INTERVAL_DURATION=60s"
                Environment="OPENSHIFT_EVICTION_MONITORING_PERIOD_DURATION=30s"
              name: 30-kubelet-interval-tuning.conf
          name: kubelet.service

18.7.6.3. SCTP

Stream Control Transmission Protocol (SCTP) is a key protocol used in RAN applications. This MachineConfig object adds the SCTP kernel module to the node to enable this protocol.

Recommended control plane node SCTP configuration (03-sctp-machine-config-master.yaml)

apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: master
  name: load-sctp-module-master
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
        - contents:
            source: data:,
            verification: {}
          filesystem: root
          mode: 420
          path: /etc/modprobe.d/sctp-blacklist.conf
        - contents:
            source: data:text/plain;charset=utf-8,sctp
          filesystem: root
          mode: 420
          path: /etc/modules-load.d/sctp-load.conf

Recommended worker node SCTP configuration (03-sctp-machine-config-worker.yaml)

apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: worker
  name: load-sctp-module-worker
spec:
  config:
    ignition:
      version: 2.2.0
    storage:
      files:
        - contents:
            source: data:,
            verification: {}
          filesystem: root
          mode: 420
          path: /etc/modprobe.d/sctp-blacklist.conf
        - contents:
            source: data:text/plain;charset=utf-8,sctp
          filesystem: root
          mode: 420
          path: /etc/modules-load.d/sctp-load.conf

18.7.6.4. Setting rcu_normal

The following MachineConfig CR configures the system to set rcu_normal to 1 after the system has finished startup. This improves kernel latency for vDU applications.

Recommended configuration for disabling rcu_expedited after the node has finished startup (08-set-rcu-normal-master.yaml)

apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: master
  name: 08-set-rcu-normal-master
spec:
  config:
    ignition:
      version: 3.2.0
    storage:
      files:
        - contents:
            source: data:text/plain;charset=utf-8;base64,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
          mode: 493
          path: /usr/local/bin/set-rcu-normal.sh
    systemd:
      units:
        - contents: |
            [Unit]
            Description=Disable rcu_expedited after node has finished booting by setting rcu_normal to 1

            [Service]
            Type=simple
            ExecStart=/usr/local/bin/set-rcu-normal.sh

            # Maximum wait time is 600s = 10m:
            Environment=MAXIMUM_WAIT_TIME=600

            # Steady-state threshold = 2%
            # Allowed values:
            #  4  - absolute pod count (+/-)
            #  4% - percent change (+/-)
            #  -1 - disable the steady-state check
            # Note: '%' must be escaped as '%%' in systemd unit files
            Environment=STEADY_STATE_THRESHOLD=2%%

            # Steady-state window = 120s
            # If the running pod count stays within the given threshold for this time
            # period, return CPU utilization to normal before the maximum wait time has
            # expires
            Environment=STEADY_STATE_WINDOW=120

            # Steady-state minimum = 40
            # Increasing this will skip any steady-state checks until the count rises above
            # this number to avoid false positives if there are some periods where the
            # count doesn't increase but we know we can't be at steady-state yet.
            Environment=STEADY_STATE_MINIMUM=40

            [Install]
            WantedBy=multi-user.target
          enabled: true
          name: set-rcu-normal.service

18.7.6.5. Automatic kernel crash dumps with kdump

kdump is a Linux kernel feature that creates a kernel crash dump when the kernel crashes. kdump is enabled with the following MachineConfig CRs.

Recommended MachineConfig CR to remove ice driver from control plane kdump logs (05-kdump-config-master.yaml)

apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: master
  name: 05-kdump-config-master
spec:
  config:
    ignition:
      version: 3.2.0
    systemd:
      units:
        - enabled: true
          name: kdump-remove-ice-module.service
          contents: |
            [Unit]
            Description=Remove ice module when doing kdump
            Before=kdump.service
            [Service]
            Type=oneshot
            RemainAfterExit=true
            ExecStart=/usr/local/bin/kdump-remove-ice-module.sh
            [Install]
            WantedBy=multi-user.target
    storage:
      files:
        - contents:
            source: data:text/plain;charset=utf-8;base64,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
          mode: 448
          path: /usr/local/bin/kdump-remove-ice-module.sh

Recommended control plane node kdump configuration (06-kdump-master.yaml)

apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: master
  name: 06-kdump-enable-master
spec:
  config:
    ignition:
      version: 3.2.0
    systemd:
      units:
        - enabled: true
          name: kdump.service
  kernelArguments:
    - crashkernel=512M

Recommended MachineConfig CR to remove ice driver from worker node kdump logs (05-kdump-config-worker.yaml)

apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: worker
  name: 05-kdump-config-worker
spec:
  config:
    ignition:
      version: 3.2.0
    systemd:
      units:
        - enabled: true
          name: kdump-remove-ice-module.service
          contents: |
            [Unit]
            Description=Remove ice module when doing kdump
            Before=kdump.service
            [Service]
            Type=oneshot
            RemainAfterExit=true
            ExecStart=/usr/local/bin/kdump-remove-ice-module.sh
            [Install]
            WantedBy=multi-user.target
    storage:
      files:
        - contents:
            source: data:text/plain;charset=utf-8;base64,IyEvdXNyL2Jpbi9lbnYgYmFzaAoKIyBUaGlzIHNjcmlwdCByZW1vdmVzIHRoZSBpY2UgbW9kdWxlIGZyb20ga2R1bXAgdG8gcHJldmVudCBrZHVtcCBmYWlsdXJlcyBvbiBjZXJ0YWluIHNlcnZlcnMuCiMgVGhpcyBpcyBhIHRlbXBvcmFyeSB3b3JrYXJvdW5kIGZvciBSSEVMUExBTi0xMzgyMzYgYW5kIGNhbiBiZSByZW1vdmVkIHdoZW4gdGhhdCBpc3N1ZSBpcwojIGZpeGVkLgoKc2V0IC14CgpTRUQ9Ii91c3IvYmluL3NlZCIKR1JFUD0iL3Vzci9iaW4vZ3JlcCIKCiMgb3ZlcnJpZGUgZm9yIHRlc3RpbmcgcHVycG9zZXMKS0RVTVBfQ09ORj0iJHsxOi0vZXRjL3N5c2NvbmZpZy9rZHVtcH0iClJFTU9WRV9JQ0VfU1RSPSJtb2R1bGVfYmxhY2tsaXN0PWljZSIKCiMgZXhpdCBpZiBmaWxlIGRvZXNuJ3QgZXhpc3QKWyAhIC1mICR7S0RVTVBfQ09ORn0gXSAmJiBleGl0IDAKCiMgZXhpdCBpZiBmaWxlIGFscmVhZHkgdXBkYXRlZAoke0dSRVB9IC1GcSAke1JFTU9WRV9JQ0VfU1RSfSAke0tEVU1QX0NPTkZ9ICYmIGV4aXQgMAoKIyBUYXJnZXQgbGluZSBsb29rcyBzb21ldGhpbmcgbGlrZSB0aGlzOgojIEtEVU1QX0NPTU1BTkRMSU5FX0FQUEVORD0iaXJxcG9sbCBucl9jcHVzPTEgLi4uIGhlc3RfZGlzYWJsZSIKIyBVc2Ugc2VkIHRvIG1hdGNoIGV2ZXJ5dGhpbmcgYmV0d2VlbiB0aGUgcXVvdGVzIGFuZCBhcHBlbmQgdGhlIFJFTU9WRV9JQ0VfU1RSIHRvIGl0CiR7U0VEfSAtaSAncy9eS0RVTVBfQ09NTUFORExJTkVfQVBQRU5EPSJbXiJdKi8mICcke1JFTU9WRV9JQ0VfU1RSfScvJyAke0tEVU1QX0NPTkZ9IHx8IGV4aXQgMAo=
          mode: 448
          path: /usr/local/bin/kdump-remove-ice-module.sh

Recommended kdump worker node configuration (06-kdump-worker.yaml)

apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: worker
  name: 06-kdump-enable-worker
spec:
  config:
    ignition:
      version: 3.2.0
    systemd:
      units:
        - enabled: true
          name: kdump.service
  kernelArguments:
    - crashkernel=512M

18.7.6.6. Disable automatic CRI-O cache wipe

After an uncontrolled host shutdown or cluster reboot, CRI-O automatically deletes the entire CRI-O cache, causing all images to be pulled from the registry when the node reboots. This can result in unacceptably slow recovery times or recovery failures. To prevent this from happening in single-node OpenShift clusters that you install with GitOps ZTP, disable the CRI-O delete cache feature during cluster installation.

Recommended MachineConfig CR to disable CRI-O cache wipe on control plane nodes (99-crio-disable-wipe-master.yaml)

apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: master
  name: 99-crio-disable-wipe-master
spec:
  config:
    ignition:
      version: 3.2.0
    storage:
      files:
        - contents:
            source: data:text/plain;charset=utf-8;base64,W2NyaW9dCmNsZWFuX3NodXRkb3duX2ZpbGUgPSAiIgo=
          mode: 420
          path: /etc/crio/crio.conf.d/99-crio-disable-wipe.toml

Recommended MachineConfig CR to disable CRI-O cache wipe on worker nodes (99-crio-disable-wipe-worker.yaml)

apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: worker
  name: 99-crio-disable-wipe-worker
spec:
  config:
    ignition:
      version: 3.2.0
    storage:
      files:
        - contents:
            source: data:text/plain;charset=utf-8;base64,W2NyaW9dCmNsZWFuX3NodXRkb3duX2ZpbGUgPSAiIgo=
          mode: 420
          path: /etc/crio/crio.conf.d/99-crio-disable-wipe.toml

18.7.6.7. Configuring crun as the default container runtime

The following ContainerRuntimeConfig custom resources (CRs) configure crun as the default OCI container runtime for control plane and worker nodes. The crun container runtime is fast and lightweight and has a low memory footprint.

Important

For optimal performance, enable crun for control plane and worker nodes in single-node OpenShift, three-node OpenShift, and standard clusters. To avoid the cluster rebooting when the CR is applied, apply the change as a GitOps ZTP additional Day 0 install-time manifest.

Recommended ContainerRuntimeConfig CR for control plane nodes (enable-crun-master.yaml)

apiVersion: machineconfiguration.openshift.io/v1
kind: ContainerRuntimeConfig
metadata:
  name: enable-crun-master
spec:
  machineConfigPoolSelector:
    matchLabels:
      pools.operator.machineconfiguration.openshift.io/master: ""
  containerRuntimeConfig:
    defaultRuntime: crun

Recommended ContainerRuntimeConfig CR for worker nodes (enable-crun-worker.yaml)

apiVersion: machineconfiguration.openshift.io/v1
kind: ContainerRuntimeConfig
metadata:
  name: enable-crun-worker
spec:
  machineConfigPoolSelector:
    matchLabels:
      pools.operator.machineconfiguration.openshift.io/worker: ""
  containerRuntimeConfig:
    defaultRuntime: crun

18.7.7. Recommended postinstallation cluster configurations

When the cluster installation is complete, the ZTP pipeline applies the following custom resources (CRs) that are required to run DU workloads.

Note

In GitOps ZTP v4.10 and earlier, you configure UEFI secure boot with a MachineConfig CR. This is no longer required in GitOps ZTP v4.11 and later. In v4.11, you configure UEFI secure boot for single-node OpenShift clusters by updating the spec.clusters.nodes.bootMode field in the SiteConfig CR that you use to install the cluster. For more information, see Deploying a managed cluster with SiteConfig and GitOps ZTP.

18.7.7.1. Operators

Single-node OpenShift clusters that run DU workloads require the following Operators to be installed:

Local Storage Operator
Logging Operator
PTP Operator
SR-IOV Network Operator

You also need to configure a custom CatalogSource CR, disable the default OperatorHub configuration, and configure an ImageContentSourcePolicy mirror registry that is accessible from the clusters that you install.

Recommended Storage Operator namespace and Operator group configuration (StorageNS.yaml, StorageOperGroup.yaml)

---
apiVersion: v1
kind: Namespace
metadata:
  name: openshift-local-storage
  annotations:
    workload.openshift.io/allowed: management
---
apiVersion: operators.coreos.com/v1
kind: OperatorGroup
metadata:
  name: openshift-local-storage
  namespace: openshift-local-storage
  annotations: {}
spec:
  targetNamespaces:
    - openshift-local-storage

Recommended Cluster Logging Operator namespace and Operator group configuration (ClusterLogNS.yaml, ClusterLogOperGroup.yaml)

---
apiVersion: v1
kind: Namespace
metadata:
  name: openshift-logging
  annotations:
    workload.openshift.io/allowed: management
---
apiVersion: operators.coreos.com/v1
kind: OperatorGroup
metadata:
  name: cluster-logging
  namespace: openshift-logging
  annotations: {}
spec:
  targetNamespaces:
    - openshift-logging

Recommended PTP Operator namespace and Operator group configuration (PtpSubscriptionNS.yaml, PtpSubscriptionOperGroup.yaml)

---
apiVersion: v1
kind: Namespace
metadata:
  name: openshift-ptp
  annotations:
    workload.openshift.io/allowed: management
  labels:
    openshift.io/cluster-monitoring: "true"
---
apiVersion: operators.coreos.com/v1
kind: OperatorGroup
metadata:
  name: ptp-operators
  namespace: openshift-ptp
  annotations: {}
spec:
  targetNamespaces:
    - openshift-ptp

Recommended SR-IOV Operator namespace and Operator group configuration (SriovSubscriptionNS.yaml, SriovSubscriptionOperGroup.yaml)

---
apiVersion: v1
kind: Namespace
metadata:
  name: openshift-sriov-network-operator
  annotations:
    workload.openshift.io/allowed: management
---
apiVersion: operators.coreos.com/v1
kind: OperatorGroup
metadata:
  name: sriov-network-operators
  namespace: openshift-sriov-network-operator
  annotations: {}
spec:
  targetNamespaces:
    - openshift-sriov-network-operator

Recommended CatalogSource configuration (DefaultCatsrc.yaml)

apiVersion: operators.coreos.com/v1alpha1
kind: CatalogSource
metadata:
  name: default-cat-source
  namespace: openshift-marketplace
  annotations:
    target.workload.openshift.io/management: '{"effect": "PreferredDuringScheduling"}'
spec:
  displayName: default-cat-source
  image: $imageUrl
  publisher: Red Hat
  sourceType: grpc
  updateStrategy:
    registryPoll:
      interval: 1h
status:
  connectionState:
    lastObservedState: READY

Recommended ImageContentSourcePolicy configuration (DisconnectedICSP.yaml)

apiVersion: operator.openshift.io/v1alpha1
kind: ImageContentSourcePolicy
metadata:
  name: disconnected-internal-icsp
  annotations: {}
spec:
  repositoryDigestMirrors:
    - $mirrors

Recommended OperatorHub configuration (OperatorHub.yaml)

apiVersion: config.openshift.io/v1
kind: OperatorHub
metadata:
  name: cluster
  annotations: {}
spec:
  disableAllDefaultSources: true

18.7.7.2. Operator subscriptions

Single-node OpenShift clusters that run DU workloads require the following Subscription CRs. The subscription provides the location to download the following Operators:

Local Storage Operator
Logging Operator
PTP Operator
SR-IOV Network Operator
SRIOV-FEC Operator

For each Operator subscription, specify the channel to get the Operator from. The recommended channel is stable.

You can specify Manual or Automatic updates. In Automatic mode, the Operator automatically updates to the latest versions in the channel as they become available in the registry. In Manual mode, new Operator versions are installed only when they are explicitly approved.

Tip

Use Manual mode for subscriptions. This allows you to control the timing of Operator updates to fit within scheduled maintenance windows.

Recommended Local Storage Operator subscription (StorageSubscription.yaml)

apiVersion: operators.coreos.com/v1alpha1
kind: Subscription
metadata:
  name: local-storage-operator
  namespace: openshift-local-storage
  annotations: {}
spec:
  channel: "stable"
  name: local-storage-operator
  source: redhat-operators-disconnected
  sourceNamespace: openshift-marketplace
  installPlanApproval: Manual
status:
  state: AtLatestKnown

Recommended SR-IOV Operator subscription (SriovSubscription.yaml)

apiVersion: operators.coreos.com/v1alpha1
kind: Subscription
metadata:
  name: sriov-network-operator-subscription
  namespace: openshift-sriov-network-operator
  annotations: {}
spec:
  channel: "stable"
  name: sriov-network-operator
  source: redhat-operators-disconnected
  sourceNamespace: openshift-marketplace
  installPlanApproval: Manual
status:
  state: AtLatestKnown

Recommended PTP Operator subscription (PtpSubscription.yaml)

---
apiVersion: operators.coreos.com/v1alpha1
kind: Subscription
metadata:
  name: ptp-operator-subscription
  namespace: openshift-ptp
  annotations: {}
spec:
  channel: "stable"
  name: ptp-operator
  source: redhat-operators-disconnected
  sourceNamespace: openshift-marketplace
  installPlanApproval: Manual
status:
  state: AtLatestKnown

Recommended Cluster Logging Operator subscription (ClusterLogSubscription.yaml)

apiVersion: operators.coreos.com/v1alpha1
kind: Subscription
metadata:
  name: cluster-logging
  namespace: openshift-logging
  annotations: {}
spec:
  channel: "stable"
  name: cluster-logging
  source: redhat-operators-disconnected
  sourceNamespace: openshift-marketplace
  installPlanApproval: Manual
status:
  state: AtLatestKnown

18.7.7.3. Cluster logging and log forwarding

Single-node OpenShift clusters that run DU workloads require logging and log forwarding for debugging. The following ClusterLogging and ClusterLogForwarder custom resources (CRs) are required.

Recommended cluster logging configuration (ClusterLogging.yaml)

apiVersion: logging.openshift.io/v1
kind: ClusterLogging
metadata:
  name: instance
  namespace: openshift-logging
  annotations: {}
spec:
  managementState: "Managed"
  collection:
    logs:
      type: "vector"

Recommended log forwarding configuration (ClusterLogForwarder.yaml)

apiVersion: "logging.openshift.io/v1"
kind: ClusterLogForwarder
metadata:
  name: instance
  namespace: openshift-logging
  annotations: {}
spec:
  outputs: $outputs
  pipelines: $pipelines

Set the spec.outputs.url field to the URL of the Kafka server where the logs are forwarded to.

18.7.7.4. Performance profile

Single-node OpenShift clusters that run DU workloads require a Node Tuning Operator performance profile to use real-time host capabilities and services.

Note

The following example PerformanceProfile CR illustrates the required single-node OpenShift cluster configuration.

Recommended performance profile configuration (PerformanceProfile.yaml)

apiVersion: performance.openshift.io/v2
kind: PerformanceProfile
metadata:
  # if you change this name make sure the 'include' line in TunedPerformancePatch.yaml
  # matches this name: include=openshift-node-performance-${PerformanceProfile.metadata.name}
  # Also in file 'validatorCRs/informDuValidator.yaml':
  # name: 50-performance-${PerformanceProfile.metadata.name}
  name: openshift-node-performance-profile
  annotations:
    ran.openshift.io/reference-configuration: "ran-du.redhat.com"
spec:
  additionalKernelArgs:
    - "rcupdate.rcu_normal_after_boot=0"
    - "efi=runtime"
    - "vfio_pci.enable_sriov=1"
    - "vfio_pci.disable_idle_d3=1"
    - "module_blacklist=irdma"
  cpu:
    isolated: $isolated
    reserved: $reserved
  hugepages:
    defaultHugepagesSize: $defaultHugepagesSize
    pages:
      - size: $size
        count: $count
        node: $node
  machineConfigPoolSelector:
    pools.operator.machineconfiguration.openshift.io/$mcp: ""
  nodeSelector:
    node-role.kubernetes.io/$mcp: ""
  numa:
    topologyPolicy: "restricted"
  # To use the standard (non-realtime) kernel, set enabled to false
  realTimeKernel:
    enabled: true
  workloadHints:
    # WorkloadHints defines the set of upper level flags for different type of workloads.
    # See https://github.com/openshift/cluster-node-tuning-operator/blob/master/docs/performanceprofile/performance_profile.md#workloadhints
    # for detailed descriptions of each item.
    # The configuration below is set for a low latency, performance mode.
    realTime: true
    highPowerConsumption: false
    perPodPowerManagement: false

Table 18.13. PerformanceProfile CR options for single-node OpenShift clusters
PerformanceProfile CR field	Description
`metadata.name`	Ensure that `name` matches the following fields set in related GitOps ZTP custom resources (CRs): `include=openshift-node-performance-${PerformanceProfile.metadata.name}` in `TunedPerformancePatch.yaml` `name: 50-performance-${PerformanceProfile.metadata.name}` in `validatorCRs/informDuValidator.yaml`
`spec.additionalKernelArgs`	`"efi=runtime"` Configures UEFI secure boot for the cluster host.
`spec.cpu.isolated`	Set the isolated CPUs. Ensure all of the Hyper-Threading pairs match. Important The reserved and isolated CPU pools must not overlap and together must span all available cores. CPU cores that are not accounted for cause an undefined behaviour in the system.
`spec.cpu.reserved`	Set the reserved CPUs. When workload partitioning is enabled, system processes, kernel threads, and system container threads are restricted to these CPUs. All CPUs that are not isolated should be reserved.
`spec.hugepages.pages`	Set the number of huge pages (`count`) Set the huge pages size (`size`). Set `node` to the NUMA node where the `hugepages` are allocated (`node`)
`spec.realTimeKernel`	Set `enabled` to `true` to use the realtime kernel.
`spec.workloadHints`	Use `workloadHints` to define the set of top level flags for different type of workloads. The example configuration configures the cluster for low latency and high performance.

18.7.7.5. Configuring cluster time synchronization

Run a one-time system time synchronization job for control plane or worker nodes.

Recommended one time time-sync for control plane nodes (99-sync-time-once-master.yaml)

apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: master
  name: 99-sync-time-once-master
spec:
  config:
    ignition:
      version: 3.2.0
    systemd:
      units:
        - contents: |
            [Unit]
            Description=Sync time once
            After=network.service
            [Service]
            Type=oneshot
            TimeoutStartSec=300
            ExecStart=/usr/sbin/chronyd -n -f /etc/chrony.conf -q
            RemainAfterExit=yes
            [Install]
            WantedBy=multi-user.target
          enabled: true
          name: sync-time-once.service

Recommended one time time-sync for worker nodes (99-sync-time-once-worker.yaml)

apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: worker
  name: 99-sync-time-once-worker
spec:
  config:
    ignition:
      version: 3.2.0
    systemd:
      units:
        - contents: |
            [Unit]
            Description=Sync time once
            After=network.service
            [Service]
            Type=oneshot
            TimeoutStartSec=300
            ExecStart=/usr/sbin/chronyd -n -f /etc/chrony.conf -q
            RemainAfterExit=yes
            [Install]
            WantedBy=multi-user.target
          enabled: true
          name: sync-time-once.service

18.7.7.6. PTP

Single-node OpenShift clusters use Precision Time Protocol (PTP) for network time synchronization. The following example PtpConfig CRs illustrate the required PTP configurations for ordinary clocks, boundary clocks, and grandmaster clocks. The exact configuration you apply will depend on the node hardware and specific use case.

Recommended PTP ordinary clock configuration (PtpConfigSlave.yaml)

apiVersion: ptp.openshift.io/v1
kind: PtpConfig
metadata:
  name: ordinary
  namespace: openshift-ptp
  annotations: {}
spec:
  profile:
    - name: "ordinary"
      # The interface name is hardware-specific
      interface: $interface
      ptp4lOpts: "-2 -s"
      phc2sysOpts: "-a -r -n 24"
      ptpSchedulingPolicy: SCHED_FIFO
      ptpSchedulingPriority: 10
      ptpSettings:
        logReduce: "true"
      ptp4lConf: |
        [global]
        #
        # Default Data Set
        #
        twoStepFlag 1
        slaveOnly 1
        priority1 128
        priority2 128
        domainNumber 24
        #utc_offset 37
        clockClass 255
        clockAccuracy 0xFE
        offsetScaledLogVariance 0xFFFF
        free_running 0
        freq_est_interval 1
        dscp_event 0
        dscp_general 0
        dataset_comparison G.8275.x
        G.8275.defaultDS.localPriority 128
        #
        # Port Data Set
        #
        logAnnounceInterval -3
        logSyncInterval -4
        logMinDelayReqInterval -4
        logMinPdelayReqInterval -4
        announceReceiptTimeout 3
        syncReceiptTimeout 0
        delayAsymmetry 0
        fault_reset_interval -4
        neighborPropDelayThresh 20000000
        masterOnly 0
        G.8275.portDS.localPriority 128
        #
        # Run time options
        #
        assume_two_step 0
        logging_level 6
        path_trace_enabled 0
        follow_up_info 0
        hybrid_e2e 0
        inhibit_multicast_service 0
        net_sync_monitor 0
        tc_spanning_tree 0
        tx_timestamp_timeout 50
        unicast_listen 0
        unicast_master_table 0
        unicast_req_duration 3600
        use_syslog 1
        verbose 0
        summary_interval 0
        kernel_leap 1
        check_fup_sync 0
        clock_class_threshold 7
        #
        # Servo Options
        #
        pi_proportional_const 0.0
        pi_integral_const 0.0
        pi_proportional_scale 0.0
        pi_proportional_exponent -0.3
        pi_proportional_norm_max 0.7
        pi_integral_scale 0.0
        pi_integral_exponent 0.4
        pi_integral_norm_max 0.3
        step_threshold 2.0
        first_step_threshold 0.00002
        max_frequency 900000000
        clock_servo pi
        sanity_freq_limit 200000000
        ntpshm_segment 0
        #
        # Transport options
        #
        transportSpecific 0x0
        ptp_dst_mac 01:1B:19:00:00:00
        p2p_dst_mac 01:80:C2:00:00:0E
        udp_ttl 1
        udp6_scope 0x0E
        uds_address /var/run/ptp4l
        #
        # Default interface options
        #
        clock_type OC
        network_transport L2
        delay_mechanism E2E
        time_stamping hardware
        tsproc_mode filter
        delay_filter moving_median
        delay_filter_length 10
        egressLatency 0
        ingressLatency 0
        boundary_clock_jbod 0
        #
        # Clock description
        #
        productDescription ;;
        revisionData ;;
        manufacturerIdentity 00:00:00
        userDescription ;
        timeSource 0xA0
  recommend:
    - profile: "ordinary"
      priority: 4
      match:
        - nodeLabel: "node-role.kubernetes.io/$mcp"

Recommended boundary clock configuration (PtpConfigBoundary.yaml)

apiVersion: ptp.openshift.io/v1
kind: PtpConfig
metadata:
  name: boundary
  namespace: openshift-ptp
  annotations: {}
spec:
  profile:
    - name: "boundary"
      ptp4lOpts: "-2"
      phc2sysOpts: "-a -r -n 24"
      ptpSchedulingPolicy: SCHED_FIFO
      ptpSchedulingPriority: 10
      ptpSettings:
        logReduce: "true"
      ptp4lConf: |
        # The interface name is hardware-specific
        [$iface_slave]
        masterOnly 0
        [$iface_master_1]
        masterOnly 1
        [$iface_master_2]
        masterOnly 1
        [$iface_master_3]
        masterOnly 1
        [global]
        #
        # Default Data Set
        #
        twoStepFlag 1
        slaveOnly 0
        priority1 128
        priority2 128
        domainNumber 24
        #utc_offset 37
        clockClass 248
        clockAccuracy 0xFE
        offsetScaledLogVariance 0xFFFF
        free_running 0
        freq_est_interval 1
        dscp_event 0
        dscp_general 0
        dataset_comparison G.8275.x
        G.8275.defaultDS.localPriority 128
        #
        # Port Data Set
        #
        logAnnounceInterval -3
        logSyncInterval -4
        logMinDelayReqInterval -4
        logMinPdelayReqInterval -4
        announceReceiptTimeout 3
        syncReceiptTimeout 0
        delayAsymmetry 0
        fault_reset_interval -4
        neighborPropDelayThresh 20000000
        masterOnly 0
        G.8275.portDS.localPriority 128
        #
        # Run time options
        #
        assume_two_step 0
        logging_level 6
        path_trace_enabled 0
        follow_up_info 0
        hybrid_e2e 0
        inhibit_multicast_service 0
        net_sync_monitor 0
        tc_spanning_tree 0
        tx_timestamp_timeout 50
        unicast_listen 0
        unicast_master_table 0
        unicast_req_duration 3600
        use_syslog 1
        verbose 0
        summary_interval 0
        kernel_leap 1
        check_fup_sync 0
        clock_class_threshold 135
        #
        # Servo Options
        #
        pi_proportional_const 0.0
        pi_integral_const 0.0
        pi_proportional_scale 0.0
        pi_proportional_exponent -0.3
        pi_proportional_norm_max 0.7
        pi_integral_scale 0.0
        pi_integral_exponent 0.4
        pi_integral_norm_max 0.3
        step_threshold 2.0
        first_step_threshold 0.00002
        max_frequency 900000000
        clock_servo pi
        sanity_freq_limit 200000000
        ntpshm_segment 0
        #
        # Transport options
        #
        transportSpecific 0x0
        ptp_dst_mac 01:1B:19:00:00:00
        p2p_dst_mac 01:80:C2:00:00:0E
        udp_ttl 1
        udp6_scope 0x0E
        uds_address /var/run/ptp4l
        #
        # Default interface options
        #
        clock_type BC
        network_transport L2
        delay_mechanism E2E
        time_stamping hardware
        tsproc_mode filter
        delay_filter moving_median
        delay_filter_length 10
        egressLatency 0
        ingressLatency 0
        boundary_clock_jbod 0
        #
        # Clock description
        #
        productDescription ;;
        revisionData ;;
        manufacturerIdentity 00:00:00
        userDescription ;
        timeSource 0xA0
  recommend:
    - profile: "boundary"
      priority: 4
      match:
        - nodeLabel: "node-role.kubernetes.io/$mcp"

Recommended PTP Westport Channel e810 grandmaster clock configuration (PtpConfigGmWpc.yaml)

# The grandmaster profile is provided for testing only
# It is not installed on production clusters
apiVersion: ptp.openshift.io/v1
kind: PtpConfig
metadata:
  name: grandmaster
  namespace: openshift-ptp
  annotations: {}
spec:
  profile:
    - name: "grandmaster"
      ptp4lOpts: "-2 --summary_interval -4"
      phc2sysOpts: -r -u 0 -m -O -37 -N 8 -R 16 -s $iface_master -n 24
      ptpSchedulingPolicy: SCHED_FIFO
      ptpSchedulingPriority: 10
      ptpSettings:
        logReduce: "true"
      plugins:
        e810:
          enableDefaultConfig: false
          settings:
            LocalMaxHoldoverOffSet: 1500
            LocalHoldoverTimeout: 14400
            MaxInSpecOffset: 100
          pins: $e810_pins
          #  "$iface_master":
          #    "U.FL2": "0 2"
          #    "U.FL1": "0 1"
          #    "SMA2": "0 2"
          #    "SMA1": "0 1"
          ublxCmds:
            - args: #ubxtool -P 29.20 -z CFG-HW-ANT_CFG_VOLTCTRL,1
                - "-P"
                - "29.20"
                - "-z"
                - "CFG-HW-ANT_CFG_VOLTCTRL,1"
              reportOutput: false
            - args: #ubxtool -P 29.20 -e GPS
                - "-P"
                - "29.20"
                - "-e"
                - "GPS"
              reportOutput: false
            - args: #ubxtool -P 29.20 -d Galileo
                - "-P"
                - "29.20"
                - "-d"
                - "Galileo"
              reportOutput: false
            - args: #ubxtool -P 29.20 -d GLONASS
                - "-P"
                - "29.20"
                - "-d"
                - "GLONASS"
              reportOutput: false
            - args: #ubxtool -P 29.20 -d BeiDou
                - "-P"
                - "29.20"
                - "-d"
                - "BeiDou"
              reportOutput: false
            - args: #ubxtool -P 29.20 -d SBAS
                - "-P"
                - "29.20"
                - "-d"
                - "SBAS"
              reportOutput: false
            - args: #ubxtool -P 29.20 -t -w 5 -v 1 -e SURVEYIN,600,50000
                - "-P"
                - "29.20"
                - "-t"
                - "-w"
                - "5"
                - "-v"
                - "1"
                - "-e"
                - "SURVEYIN,600,50000"
              reportOutput: true
            - args: #ubxtool -P 29.20 -p MON-HW
                - "-P"
                - "29.20"
                - "-p"
                - "MON-HW"
              reportOutput: true
            - args: #ubxtool -P 29.20 -p CFG-MSG,1,38,300
                - "-P"
                - "29.20"
                - "-p"
                - "CFG-MSG,1,38,300"
              reportOutput: true
      ts2phcOpts: " "
      ts2phcConf: |
        [nmea]
        ts2phc.master 1
        [global]
        use_syslog  0
        verbose 1
        logging_level 7
        ts2phc.pulsewidth 100000000
        #GNSS module s /dev/ttyGNSS* -al use _0
        #cat /dev/ttyGNSS_1700_0 to find available serial port
        #example value of gnss_serialport is /dev/ttyGNSS_1700_0
        ts2phc.nmea_serialport $gnss_serialport
        leapfile  /usr/share/zoneinfo/leap-seconds.list
        [$iface_master]
        ts2phc.extts_polarity rising
        ts2phc.extts_correction 0
      ptp4lConf: |
        [$iface_master]
        masterOnly 1
        [$iface_master_1]
        masterOnly 1
        [$iface_master_2]
        masterOnly 1
        [$iface_master_3]
        masterOnly 1
        [global]
        #
        # Default Data Set
        #
        twoStepFlag 1
        priority1 128
        priority2 128
        domainNumber 24
        #utc_offset 37
        clockClass 6
        clockAccuracy 0x27
        offsetScaledLogVariance 0xFFFF
        free_running 0
        freq_est_interval 1
        dscp_event 0
        dscp_general 0
        dataset_comparison G.8275.x
        G.8275.defaultDS.localPriority 128
        #
        # Port Data Set
        #
        logAnnounceInterval -3
        logSyncInterval -4
        logMinDelayReqInterval -4
        logMinPdelayReqInterval 0
        announceReceiptTimeout 3
        syncReceiptTimeout 0
        delayAsymmetry 0
        fault_reset_interval -4
        neighborPropDelayThresh 20000000
        masterOnly 0
        G.8275.portDS.localPriority 128
        #
        # Run time options
        #
        assume_two_step 0
        logging_level 6
        path_trace_enabled 0
        follow_up_info 0
        hybrid_e2e 0
        inhibit_multicast_service 0
        net_sync_monitor 0
        tc_spanning_tree 0
        tx_timestamp_timeout 50
        unicast_listen 0
        unicast_master_table 0
        unicast_req_duration 3600
        use_syslog 1
        verbose 0
        summary_interval -4
        kernel_leap 1
        check_fup_sync 0
        clock_class_threshold 7
        #
        # Servo Options
        #
        pi_proportional_const 0.0
        pi_integral_const 0.0
        pi_proportional_scale 0.0
        pi_proportional_exponent -0.3
        pi_proportional_norm_max 0.7
        pi_integral_scale 0.0
        pi_integral_exponent 0.4
        pi_integral_norm_max 0.3
        step_threshold 2.0
        first_step_threshold 0.00002
        clock_servo pi
        sanity_freq_limit  200000000
        ntpshm_segment 0
        #
        # Transport options
        #
        transportSpecific 0x0
        ptp_dst_mac 01:1B:19:00:00:00
        p2p_dst_mac 01:80:C2:00:00:0E
        udp_ttl 1
        udp6_scope 0x0E
        uds_address /var/run/ptp4l
        #
        # Default interface options
        #
        clock_type BC
        network_transport L2
        delay_mechanism E2E
        time_stamping hardware
        tsproc_mode filter
        delay_filter moving_median
        delay_filter_length 10
        egressLatency 0
        ingressLatency 0
        boundary_clock_jbod 0
        #
        # Clock description
        #
        productDescription ;;
        revisionData ;;
        manufacturerIdentity 00:00:00
        userDescription ;
        timeSource 0x20
  recommend:
    - profile: "grandmaster"
      priority: 4
      match:
        - nodeLabel: "node-role.kubernetes.io/$mcp"

The following optional PtpOperatorConfig CR configures PTP events reporting for the node.

Recommended PTP events configuration (PtpOperatorConfigForEvent.yaml)

apiVersion: ptp.openshift.io/v1
kind: PtpOperatorConfig
metadata:
  name: default
  namespace: openshift-ptp
  annotations: {}
spec:
  daemonNodeSelector:
    node-role.kubernetes.io/$mcp: ""
  ptpEventConfig:
    enableEventPublisher: true
    transportHost: "http://ptp-event-publisher-service-NODE_NAME.openshift-ptp.svc.cluster.local:9043"

18.7.7.7. Extended Tuned profile

Single-node OpenShift clusters that run DU workloads require additional performance tuning configurations necessary for high-performance workloads. The following example Tuned CR extends the Tuned profile:

Recommended extended Tuned profile configuration (TunedPerformancePatch.yaml)

apiVersion: tuned.openshift.io/v1
kind: Tuned
metadata:
  name: performance-patch
  namespace: openshift-cluster-node-tuning-operator
  annotations: {}
spec:
  profile:
    - name: performance-patch
      # Please note:
      # - The 'include' line must match the associated PerformanceProfile name, following below pattern
      #   include=openshift-node-performance-${PerformanceProfile.metadata.name}
      # - When using the standard (non-realtime) kernel, remove the kernel.timer_migration override from
      #   the [sysctl] section and remove the entire section if it is empty.
      data: |
        [main]
        summary=Configuration changes profile inherited from performance created tuned
        include=openshift-node-performance-openshift-node-performance-profile
        [sysctl]
        kernel.timer_migration=1
        [scheduler]
        group.ice-ptp=0:f:10:*:ice-ptp.*
        group.ice-gnss=0:f:10:*:ice-gnss.*
        [service]
        service.stalld=start,enable
        service.chronyd=stop,disable
  recommend:
    - machineConfigLabels:
        machineconfiguration.openshift.io/role: "$mcp"
      priority: 19
      profile: performance-patch

Table 18.14. Tuned CR options for single-node OpenShift clusters
Tuned CR field	Description
`spec.profile.data`	The `include` line that you set in `spec.profile.data` must match the associated `PerformanceProfile` CR name. For example, `include=openshift-node-performance-${PerformanceProfile.metadata.name}`. When using the non-realtime kernel, remove the `timer_migration override` line from the `[sysctl]` section.

18.7.7.8. SR-IOV

Single root I/O virtualization (SR-IOV) is commonly used to enable fronthaul and midhaul networks. The following YAML example configures SR-IOV for a single-node OpenShift cluster.

Note

The configuration of the SriovNetwork CR will vary depending on your specific network and infrastructure requirements.

Recommended SriovOperatorConfig CR configuration (SriovOperatorConfig.yaml)

apiVersion: sriovnetwork.openshift.io/v1
kind: SriovOperatorConfig
metadata:
  name: default
  namespace: openshift-sriov-network-operator
  annotations: {}
spec:
  configDaemonNodeSelector:
    "node-role.kubernetes.io/$mcp": ""
  # Injector and OperatorWebhook pods can be disabled (set to "false") below
  # to reduce the number of management pods. It is recommended to start with the
  # webhook and injector pods enabled, and only disable them after verifying the
  # correctness of user manifests.
  #   If the injector is disabled, containers using sr-iov resources must explicitly assign
  #   them in the  "requests"/"limits" section of the container spec, for example:
  #    containers:
  #    - name: my-sriov-workload-container
  #      resources:
  #        limits:
  #          openshift.io/<resource_name>:  "1"
  #        requests:
  #          openshift.io/<resource_name>:  "1"
  enableInjector: true
  enableOperatorWebhook: true
  logLevel: 0

Table 18.15. SriovOperatorConfig CR options for single-node OpenShift clusters
SriovOperatorConfig CR field	Description
`spec.enableInjector`	Disable `Injector` pods to reduce the number of management pods. Start with the `Injector` pods enabled, and only disable them after verifying the user manifests. If the injector is disabled, containers that use SR-IOV resources must explicitly assign them in the `requests` and `limits` section of the container spec. For example: containers: - name: my-sriov-workload-container resources: limits: openshift.io/<resource_name>: "1" requests: openshift.io/<resource_name>: "1"
`spec.enableOperatorWebhook`	Disable `OperatorWebhook` pods to reduce the number of management pods. Start with the `OperatorWebhook` pods enabled, and only disable them after verifying the user manifests.

Recommended SriovNetwork configuration (SriovNetwork.yaml)

apiVersion: sriovnetwork.openshift.io/v1
kind: SriovNetwork
metadata:
  name: ""
  namespace: openshift-sriov-network-operator
  annotations: {}
spec:
  #  resourceName: ""
  networkNamespace: openshift-sriov-network-operator
#  vlan: ""
#  spoofChk: ""
#  ipam: ""
#  linkState: ""
#  maxTxRate: ""
#  minTxRate: ""
#  vlanQoS: ""
#  trust: ""
#  capabilities: ""

Table 18.16. SriovNetwork CR options for single-node OpenShift clusters
SriovNetwork CR field	Description
`spec.vlan`	Configure `vlan` with the VLAN for the midhaul network.

Recommended SriovNetworkNodePolicy CR configuration (SriovNetworkNodePolicy.yaml)

apiVersion: sriovnetwork.openshift.io/v1
kind: SriovNetworkNodePolicy
metadata:
  name: $name
  namespace: openshift-sriov-network-operator
  annotations: {}
spec:
  # The attributes for Mellanox/Intel based NICs as below.
  #     deviceType: netdevice/vfio-pci
  #     isRdma: true/false
  deviceType: $deviceType
  isRdma: $isRdma
  nicSelector:
    # The exact physical function name must match the hardware used
    pfNames: [$pfNames]
  nodeSelector:
    node-role.kubernetes.io/$mcp: ""
  numVfs: $numVfs
  priority: $priority
  resourceName: $resourceName

Table 18.17. SriovNetworkPolicy CR options for single-node OpenShift clusters
SriovNetworkNodePolicy CR field	Description
`spec.deviceType`	Configure `deviceType` as `vfio-pci` or `netdevice`. For Mellanox NICs, set `deviceType: netdevice`, and `isRdma: true`. For Intel based NICs, set `deviceType: vfio-pci` and `isRdma: false`.
`spec.nicSelector.pfNames`	Specifies the interface connected to the fronthaul network.
`spec.numVfs`	Specifies the number of VFs for the fronthaul network.
`spec.nicSelector.pfNames`	The exact name of physical function must match the hardware.

Recommended SR-IOV kernel configurations (07-sriov-related-kernel-args-master.yaml)

apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: master
  name: 07-sriov-related-kernel-args-master
spec:
  config:
    ignition:
      version: 3.2.0
  kernelArguments:
    - intel_iommu=on
    - iommu=pt

18.7.7.9. Console Operator

Use the cluster capabilities feature to prevent the Console Operator from being installed. When the node is centrally managed it is not needed. Removing the Operator provides additional space and capacity for application workloads.

To disable the Console Operator during the installation of the managed cluster, set the following in the spec.clusters.0.installConfigOverrides field of the SiteConfig custom resource (CR):

installConfigOverrides:  "{\"capabilities\":{\"baselineCapabilitySet\": \"None\" }}"

18.7.7.10. Alertmanager

Single-node OpenShift clusters that run DU workloads require reduced CPU resources consumed by the OpenShift Container Platform monitoring components. The following ConfigMap custom resource (CR) disables Alertmanager.

Recommended cluster monitoring configuration (ReduceMonitoringFootprint.yaml)

apiVersion: v1
kind: ConfigMap
metadata:
  name: cluster-monitoring-config
  namespace: openshift-monitoring
  annotations: {}
data:
  config.yaml: |
    grafana:
      enabled: false
    alertmanagerMain:
      enabled: false
    telemeterClient:
      enabled: false
    prometheusK8s:
       retention: 24h

18.7.7.11. Operator Lifecycle Manager

Single-node OpenShift clusters that run distributed unit workloads require consistent access to CPU resources. Operator Lifecycle Manager (OLM) collects performance data from Operators at regular intervals, resulting in an increase in CPU utilisation. The following ConfigMap custom resource (CR) disables the collection of Operator performance data by OLM.

Recommended cluster OLM configuration (ReduceOLMFootprint.yaml)

apiVersion: v1
kind: ConfigMap
metadata:
  name: collect-profiles-config
  namespace: openshift-operator-lifecycle-manager
data:
  pprof-config.yaml: |
    disabled: True

18.7.7.12. LVM Storage

You can dynamically provision local storage on single-node OpenShift clusters with Logical Volume Manager (LVM) Storage.

Note

The recommended storage solution for single-node OpenShift is the Local Storage Operator. Alternatively, you can use LVM Storage but it requires additional CPU resources to be allocated.

The following YAML example configures the storage of the node to be available to OpenShift Container Platform applications.

Recommended LVMCluster configuration (StorageLVMCluster.yaml)

apiVersion: lvm.topolvm.io/v1alpha1
kind: LVMCluster
metadata:
  name: odf-lvmcluster
  namespace: openshift-storage
spec:
  storage:
    deviceClasses:
    - name: vg1
      deviceSelector:
        paths:
        - /usr/disk/by-path/pci-0000:11:00.0-nvme-1
      thinPoolConfig:
        name: thin-pool-1
        overprovisionRatio: 10
        sizePercent: 90

Table 18.18. LVMCluster CR options for single-node OpenShift clusters
LVMCluster CR field	Description
`deviceSelector.paths`	Configure the disks used for LVM storage. If no disks are specified, the LVM Storage uses all the unused disks in the specified thin pool.

18.7.7.13. Network diagnostics

Single-node OpenShift clusters that run DU workloads require less inter-pod network connectivity checks to reduce the additional load created by these pods. The following custom resource (CR) disables these checks.

Recommended network diagnostics configuration (DisableSnoNetworkDiag.yaml)

apiVersion: operator.openshift.io/v1
kind: Network
metadata:
  name: cluster
  annotations: {}
spec:
  disableNetworkDiagnostics: true

Additional resources

Deploying far edge sites using ZTP

18.8. Validating single-node OpenShift cluster tuning for vDU application workloads

Before you can deploy virtual distributed unit (vDU) applications, you need to tune and configure the cluster host firmware and various other cluster configuration settings. Use the following information to validate the cluster configuration to support vDU workloads.

Additional resources

Workload partitioning in single-node OpenShift with GitOps ZTP
Reference configuration for deploying vDUs on single-node OpenShift

18.8.1. Recommended firmware configuration for vDU cluster hosts

Use the following table as the basis to configure the cluster host firmware for vDU applications running on OpenShift Container Platform 4.14.

Note

The following table is a general recommendation for vDU cluster host firmware configuration. Exact firmware settings will depend on your requirements and specific hardware platform. Automatic setting of firmware is not handled by the zero touch provisioning pipeline.

Table 18.19. Recommended cluster host firmware settings
Firmware setting	Configuration	Description
HyperTransport (HT)	Enabled	HyperTransport (HT) bus is a bus technology developed by AMD. HT provides a high-speed link between the components in the host memory and other system peripherals.
UEFI	Enabled	Enable booting from UEFI for the vDU host.
CPU Power and Performance Policy	Performance	Set CPU Power and Performance Policy to optimize the system for performance over energy efficiency.
Uncore Frequency Scaling	Disabled	Disable Uncore Frequency Scaling to prevent the voltage and frequency of non-core parts of the CPU from being set independently.
Uncore Frequency	Maximum	Sets the non-core parts of the CPU such as cache and memory controller to their maximum possible frequency of operation.
Performance P-limit	Disabled	Disable Performance P-limit to prevent the Uncore frequency coordination of processors.
Enhanced Intel® SpeedStep Tech	Enabled	Enable Enhanced Intel SpeedStep to allow the system to dynamically adjust processor voltage and core frequency that decreases power consumption and heat production in the host.
Intel® Turbo Boost Technology	Enabled	Enable Turbo Boost Technology for Intel-based CPUs to automatically allow processor cores to run faster than the rated operating frequency if they are operating below power, current, and temperature specification limits.
Intel Configurable TDP	Enabled	Enables Thermal Design Power (TDP) for the CPU.
Configurable TDP Level	Level 2	TDP level sets the CPU power consumption required for a particular performance rating. TDP level 2 sets the CPU to the most stable performance level at the cost of power consumption.
Energy Efficient Turbo	Disabled	Disable Energy Efficient Turbo to prevent the processor from using an energy-efficiency based policy.
Hardware P-States	Enabled or Disabled	Enable OS-controlled P-States to allow power saving configurations. Disable `P-states` (performance states) to optimize the operating system and CPU for performance over power consumption.
Package C-State	C0/C1 state	Use C0 or C1 states to set the processor to a fully active state (C0) or to stop CPU internal clocks running in software (C1).
C1E	Disabled	CPU Enhanced Halt (C1E) is a power saving feature in Intel chips. Disabling C1E prevents the operating system from sending a halt command to the CPU when inactive.
Processor C6	Disabled	C6 power-saving is a CPU feature that automatically disables idle CPU cores and cache. Disabling C6 improves system performance.
Sub-NUMA Clustering	Disabled	Sub-NUMA clustering divides the processor cores, cache, and memory into multiple NUMA domains. Disabling this option can increase performance for latency-sensitive workloads.

Note

Enable global SR-IOV and VT-d settings in the firmware for the host. These settings are relevant to bare-metal environments.

Note

Enable both C-states and OS-controlled P-States to allow per pod power management.

18.8.2. Recommended cluster configurations to run vDU applications

Clusters running virtualized distributed unit (vDU) applications require a highly tuned and optimized configuration. The following information describes the various elements that you require to support vDU workloads in OpenShift Container Platform 4.14 clusters.

18.8.2.1. Recommended cluster MachineConfig CRs for single-node OpenShift clusters

Check that the MachineConfig custom resources (CRs) that you extract from the ztp-site-generate container are applied in the cluster. The CRs can be found in the extracted out/source-crs/extra-manifest/ folder.

The following MachineConfig CRs from the ztp-site-generate container configure the cluster host:

Table 18.20. Recommended GitOps ZTP MachineConfig CRs
MachineConfig CR	Description
`01-container-mount-ns-and-kubelet-conf-master.yaml` `01-container-mount-ns-and-kubelet-conf-worker.yaml`	Configures the container mount namespace and kubelet configuration.
`03-sctp-machine-config-master.yaml` `03-sctp-machine-config-worker.yaml`	Loads the SCTP kernel module. These `MachineConfig` CRs are optional and can be omitted if you do not require this kernel module.
`05-kdump-config-master.yaml` `05-kdump-config-worker.yaml` `06-kdump-master.yaml` `06-kdump-worker.yaml`	Configures kdump crash reporting for the cluster.
`07-sriov-related-kernel-args-master.yaml`	Configures SR-IOV kernel arguments in the cluster.
`08-set-rcu-normal-master.yaml` `08-set-rcu-normal-worker.yaml`	Disables `rcu_expedited` mode after the cluster has rebooted.
`99-crio-disable-wipe-master.yaml` `99-crio-disable-wipe-worker.yaml`	Disables the automatic CRI-O cache wipe following cluster reboot.
`99-sync-time-once-master.yaml` `99-sync-time-once-worker.yaml`	Configures the one-time check and adjustment of the system clock by the Chrony service.
`enable-crun-master.yaml` `enable-crun-worker.yaml`	Enables the `crun` OCI container runtime.
`extra-manifest/enable-cgroups-v1.yaml` `source-crs/extra-manifest/enable-cgroups-v1.yaml`	Enables cgroups v1 during cluster installation and when generating RHACM cluster policies.

Note

In OpenShift Container Platform 4.14 and later, you configure workload partitioning with the cpuPartitioningMode field in the SiteConfig CR.

Additional resources

Workload partitioning in single-node OpenShift with GitOps ZTP
Extracting source CRs from the ztp-site-generate container

18.8.2.2. Recommended cluster Operators

The following Operators are required for clusters running virtualized distributed unit (vDU) applications and are a part of the baseline reference configuration:

Node Tuning Operator (NTO). NTO packages functionality that was previously delivered with the Performance Addon Operator, which is now a part of NTO.
PTP Operator
SR-IOV Network Operator
Red Hat OpenShift Logging Operator
Local Storage Operator

18.8.2.3. Recommended cluster kernel configuration

Always use the latest supported real-time kernel version in your cluster. Ensure that you apply the following configurations in the cluster:

Ensure that the following additionalKernelArgs are set in the cluster performance profile:

spec:
  additionalKernelArgs:
  - "rcupdate.rcu_normal_after_boot=0"
  - "efi=runtime"
  - "module_blacklist=irdma"

Ensure that the performance-patch profile in the Tuned CR configures the correct CPU isolation set that matches the isolated CPU set in the related PerformanceProfile CR, for example:

spec:
  profile:
    - name: performance-patch
      # The 'include' line must match the associated PerformanceProfile name, for example:
      # include=openshift-node-performance-${PerformanceProfile.metadata.name}
      # When using the standard (non-realtime) kernel, remove the kernel.timer_migration override from the [sysctl] section
      data: |
        [main]
        summary=Configuration changes profile inherited from performance created tuned
        include=openshift-node-performance-openshift-node-performance-profile
        [sysctl]
        kernel.timer_migration=1
        [scheduler]
        group.ice-ptp=0:f:10:*:ice-ptp.*
        group.ice-gnss=0:f:10:*:ice-gnss.*
        [service]
        service.stalld=start,enable
        service.chronyd=stop,disable

18.8.2.4. Checking the realtime kernel version

Always use the latest version of the realtime kernel in your OpenShift Container Platform clusters. If you are unsure about the kernel version that is in use in the cluster, you can compare the current realtime kernel version to the release version with the following procedure.

Prerequisites

You have installed the OpenShift CLI (oc).
You are logged in as a user with cluster-admin privileges.
You have installed podman.

Procedure

Run the following command to get the cluster version:

$ OCP_VERSION=$(oc get clusterversion version -o jsonpath='{.status.desired.version}{"\n"}')

Get the release image SHA number:

$ DTK_IMAGE=$(oc adm release info --image-for=driver-toolkit quay.io/openshift-release-dev/ocp-release:$OCP_VERSION-x86_64)

Run the release image container and extract the kernel version that is packaged with cluster’s current release:
```
$ podman run --rm $DTK_IMAGE rpm -qa | grep 'kernel-rt-core-' | sed 's#kernel-rt-core-##'
```
Example output
```
4.18.0-305.49.1.rt7.121.el8_4.x86_64
```
This is the default realtime kernel version that ships with the release.
Note
The realtime kernel is denoted by the string .rt in the kernel version.

Verification

Check that the kernel version listed for the cluster’s current release matches actual realtime kernel that is running in the cluster. Run the following commands to check the running realtime kernel version:

Open a remote shell connection to the cluster node:
```
$ oc debug node/<node_name>
```

Check the realtime kernel version:

sh-4.4# uname -r

Example output

4.18.0-305.49.1.rt7.121.el8_4.x86_64

18.8.3. Checking that the recommended cluster configurations are applied

You can check that clusters are running the correct configuration. The following procedure describes how to check the various configurations that you require to deploy a DU application in OpenShift Container Platform 4.14 clusters.

Prerequisites

You have deployed a cluster and tuned it for vDU workloads.
You have installed the OpenShift CLI (oc).
You have logged in as a user with cluster-admin privileges.

Procedure

Check that the default OperatorHub sources are disabled. Run the following command:
```
$ oc get operatorhub cluster -o yaml
```
Example output
```
spec:
    disableAllDefaultSources: true
```
Check that all required CatalogSource resources are annotated for workload partitioning (PreferredDuringScheduling) by running the following command:
```
$ oc get catalogsource -A -o jsonpath='{range .items[*]}{.metadata.name}{" -- "}{.metadata.annotations.target\.workload\.openshift\.io/management}{"\n"}{end}'
```
Example output
```
certified-operators -- {"effect": "PreferredDuringScheduling"}
community-operators -- {"effect": "PreferredDuringScheduling"}
ran-operators 1
redhat-marketplace -- {"effect": "PreferredDuringScheduling"}
redhat-operators -- {"effect": "PreferredDuringScheduling"}
```
1
CatalogSource resources that are not annotated are also returned. In this example, the ran-operators CatalogSource resource is not annotated and does not have the PreferredDuringScheduling annotation.
Note
In a properly configured vDU cluster, only a single annotated catalog source is listed.
Check that all applicable OpenShift Container Platform Operator namespaces are annotated for workload partitioning. This includes all Operators installed with core OpenShift Container Platform and the set of additional Operators included in the reference DU tuning configuration. Run the following command:
```
$ oc get namespaces -A -o jsonpath='{range .items[*]}{.metadata.name}{" -- "}{.metadata.annotations.workload\.openshift\.io/allowed}{"\n"}{end}'
```
Example output
```
default --
openshift-apiserver -- management
openshift-apiserver-operator -- management
openshift-authentication -- management
openshift-authentication-operator -- management
```
Important
Additional Operators must not be annotated for workload partitioning. In the output from the previous command, additional Operators should be listed without any value on the right side of the -- separator.

Check that the ClusterLogging configuration is correct. Run the following commands:

Validate that the appropriate input and output logs are configured:

$ oc get -n openshift-logging ClusterLogForwarder instance -o yaml

Example output

apiVersion: logging.openshift.io/v1
kind: ClusterLogForwarder
metadata:
  creationTimestamp: "2022-07-19T21:51:41Z"
  generation: 1
  name: instance
  namespace: openshift-logging
  resourceVersion: "1030342"
  uid: 8c1a842d-80c5-447a-9150-40350bdf40f0
spec:
  inputs:
  - infrastructure: {}
    name: infra-logs
  outputs:
  - name: kafka-open
    type: kafka
    url: tcp://10.46.55.190:9092/test
  pipelines:
  - inputRefs:
    - audit
    name: audit-logs
    outputRefs:
    - kafka-open
  - inputRefs:
    - infrastructure
    name: infrastructure-logs
    outputRefs:
    - kafka-open
...

Check that the curation schedule is appropriate for your application:

$ oc get -n openshift-logging clusterloggings.logging.openshift.io instance -o yaml

Example output

apiVersion: logging.openshift.io/v1
kind: ClusterLogging
metadata:
  creationTimestamp: "2022-07-07T18:22:56Z"
  generation: 1
  name: instance
  namespace: openshift-logging
  resourceVersion: "235796"
  uid: ef67b9b8-0e65-4a10-88ff-ec06922ea796
spec:
  collection:
    logs:
      fluentd: {}
      type: fluentd
  curation:
    curator:
      schedule: 30 3 * * *
    type: curator
  managementState: Managed
...

Check that the web console is disabled (managementState: Removed) by running the following command:
```
$ oc get consoles.operator.openshift.io cluster -o jsonpath="{ .spec.managementState }"
```
Example output
```
Removed
```

Check that chronyd is disabled on the cluster node by running the following commands:

$ oc debug node/<node_name>

Check the status of chronyd on the node:

sh-4.4# chroot /host

sh-4.4# systemctl status chronyd

Example output

● chronyd.service - NTP client/server
    Loaded: loaded (/usr/lib/systemd/system/chronyd.service; disabled; vendor preset: enabled)
    Active: inactive (dead)
      Docs: man:chronyd(8)
            man:chrony.conf(5)

Check that the PTP interface is successfully synchronized to the primary clock using a remote shell connection to the linuxptp-daemon container and the PTP Management Client (pmc) tool:

Set the $PTP_POD_NAME variable with the name of the linuxptp-daemon pod by running the following command:
```
$ PTP_POD_NAME=$(oc get pods -n openshift-ptp -l app=linuxptp-daemon -o name)
```

Run the following command to check the sync status of the PTP device:

$ oc -n openshift-ptp rsh -c linuxptp-daemon-container ${PTP_POD_NAME} pmc -u -f /var/run/ptp4l.0.config -b 0 'GET PORT_DATA_SET'

Example output

sending: GET PORT_DATA_SET
  3cecef.fffe.7a7020-1 seq 0 RESPONSE MANAGEMENT PORT_DATA_SET
    portIdentity            3cecef.fffe.7a7020-1
    portState               SLAVE
    logMinDelayReqInterval  -4
    peerMeanPathDelay       0
    logAnnounceInterval     1
    announceReceiptTimeout  3
    logSyncInterval         0
    delayMechanism          1
    logMinPdelayReqInterval 0
    versionNumber           2
  3cecef.fffe.7a7020-2 seq 0 RESPONSE MANAGEMENT PORT_DATA_SET
    portIdentity            3cecef.fffe.7a7020-2
    portState               LISTENING
    logMinDelayReqInterval  0
    peerMeanPathDelay       0
    logAnnounceInterval     1
    announceReceiptTimeout  3
    logSyncInterval         0
    delayMechanism          1
    logMinPdelayReqInterval 0
    versionNumber           2

Run the following pmc command to check the PTP clock status:

$ oc -n openshift-ptp rsh -c linuxptp-daemon-container ${PTP_POD_NAME} pmc -u -f /var/run/ptp4l.0.config -b 0 'GET TIME_STATUS_NP'

Example output

sending: GET TIME_STATUS_NP
  3cecef.fffe.7a7020-0 seq 0 RESPONSE MANAGEMENT TIME_STATUS_NP
    master_offset              10 1
    ingress_time               1657275432697400530
    cumulativeScaledRateOffset +0.000000000
    scaledLastGmPhaseChange    0
    gmTimeBaseIndicator        0
    lastGmPhaseChange          0x0000'0000000000000000.0000
    gmPresent                  true 2
    gmIdentity                 3c2c30.ffff.670e00

1: master_offset should be between -100 and 100 ns.
2: Indicates that the PTP clock is synchronized to a master, and the local clock is not the grandmaster clock.

Check that the expected master offset value corresponding to the value in /var/run/ptp4l.0.config is found in the linuxptp-daemon-container log:

$ oc logs $PTP_POD_NAME -n openshift-ptp -c linuxptp-daemon-container

Example output

phc2sys[56020.341]: [ptp4l.1.config] CLOCK_REALTIME phc offset  -1731092 s2 freq -1546242 delay    497
ptp4l[56020.390]: [ptp4l.1.config] master offset         -2 s2 freq   -5863 path delay       541
ptp4l[56020.390]: [ptp4l.0.config] master offset         -8 s2 freq  -10699 path delay       533

Check that the SR-IOV configuration is correct by running the following commands:

Check that the disableDrain value in the SriovOperatorConfig resource is set to true:

$ oc get sriovoperatorconfig -n openshift-sriov-network-operator default -o jsonpath="{.spec.disableDrain}{'\n'}"

Example output

true

Check that the SriovNetworkNodeState sync status is Succeeded by running the following command:

$ oc get SriovNetworkNodeStates -n openshift-sriov-network-operator -o jsonpath="{.items[*].status.syncStatus}{'\n'}"

Example output

Succeeded

Verify that the expected number and configuration of virtual functions (Vfs) under each interface configured for SR-IOV is present and correct in the .status.interfaces field. For example:

$ oc get SriovNetworkNodeStates -n openshift-sriov-network-operator -o yaml

Example output

apiVersion: v1
items:
- apiVersion: sriovnetwork.openshift.io/v1
  kind: SriovNetworkNodeState
...
  status:
    interfaces:
    ...
    - Vfs:
      - deviceID: 154c
        driver: vfio-pci
        pciAddress: 0000:3b:0a.0
        vendor: "8086"
        vfID: 0
      - deviceID: 154c
        driver: vfio-pci
        pciAddress: 0000:3b:0a.1
        vendor: "8086"
        vfID: 1
      - deviceID: 154c
        driver: vfio-pci
        pciAddress: 0000:3b:0a.2
        vendor: "8086"
        vfID: 2
      - deviceID: 154c
        driver: vfio-pci
        pciAddress: 0000:3b:0a.3
        vendor: "8086"
        vfID: 3
      - deviceID: 154c
        driver: vfio-pci
        pciAddress: 0000:3b:0a.4
        vendor: "8086"
        vfID: 4
      - deviceID: 154c
        driver: vfio-pci
        pciAddress: 0000:3b:0a.5
        vendor: "8086"
        vfID: 5
      - deviceID: 154c
        driver: vfio-pci
        pciAddress: 0000:3b:0a.6
        vendor: "8086"
        vfID: 6
      - deviceID: 154c
        driver: vfio-pci
        pciAddress: 0000:3b:0a.7
        vendor: "8086"
        vfID: 7

Check that the cluster performance profile is correct. The cpu and hugepages sections will vary depending on your hardware configuration. Run the following command:

$ oc get PerformanceProfile openshift-node-performance-profile -o yaml

Example output

apiVersion: performance.openshift.io/v2
kind: PerformanceProfile
metadata:
  creationTimestamp: "2022-07-19T21:51:31Z"
  finalizers:
  - foreground-deletion
  generation: 1
  name: openshift-node-performance-profile
  resourceVersion: "33558"
  uid: 217958c0-9122-4c62-9d4d-fdc27c31118c
spec:
  additionalKernelArgs:
  - idle=poll
  - rcupdate.rcu_normal_after_boot=0
  - efi=runtime
  cpu:
    isolated: 2-51,54-103
    reserved: 0-1,52-53
  hugepages:
    defaultHugepagesSize: 1G
    pages:
    - count: 32
      size: 1G
  machineConfigPoolSelector:
    pools.operator.machineconfiguration.openshift.io/master: ""
  net:
    userLevelNetworking: true
  nodeSelector:
    node-role.kubernetes.io/master: ""
  numa:
    topologyPolicy: restricted
  realTimeKernel:
    enabled: true
status:
  conditions:
  - lastHeartbeatTime: "2022-07-19T21:51:31Z"
    lastTransitionTime: "2022-07-19T21:51:31Z"
    status: "True"
    type: Available
  - lastHeartbeatTime: "2022-07-19T21:51:31Z"
    lastTransitionTime: "2022-07-19T21:51:31Z"
    status: "True"
    type: Upgradeable
  - lastHeartbeatTime: "2022-07-19T21:51:31Z"
    lastTransitionTime: "2022-07-19T21:51:31Z"
    status: "False"
    type: Progressing
  - lastHeartbeatTime: "2022-07-19T21:51:31Z"
    lastTransitionTime: "2022-07-19T21:51:31Z"
    status: "False"
    type: Degraded
  runtimeClass: performance-openshift-node-performance-profile
  tuned: openshift-cluster-node-tuning-operator/openshift-node-performance-openshift-node-performance-profile

Note

CPU settings are dependent on the number of cores available on the server and should align with workload partitioning settings. hugepages configuration is server and application dependent.

Check that the PerformanceProfile was successfully applied to the cluster by running the following command:

$ oc get performanceprofile openshift-node-performance-profile -o jsonpath="{range .status.conditions[*]}{ @.type }{' -- '}{@.status}{'\n'}{end}"

Example output

Available -- True
Upgradeable -- True
Progressing -- False
Degraded -- False

Check the Tuned performance patch settings by running the following command:

$ oc get tuneds.tuned.openshift.io -n openshift-cluster-node-tuning-operator performance-patch -o yaml

Example output

apiVersion: tuned.openshift.io/v1
kind: Tuned
metadata:
  creationTimestamp: "2022-07-18T10:33:52Z"
  generation: 1
  name: performance-patch
  namespace: openshift-cluster-node-tuning-operator
  resourceVersion: "34024"
  uid: f9799811-f744-4179-bf00-32d4436c08fd
spec:
  profile:
  - data: |
      [main]
      summary=Configuration changes profile inherited from performance created tuned
      include=openshift-node-performance-openshift-node-performance-profile
      [bootloader]
      cmdline_crash=nohz_full=2-23,26-47 1
      [sysctl]
      kernel.timer_migration=1
      [scheduler]
      group.ice-ptp=0:f:10:*:ice-ptp.*
      [service]
      service.stalld=start,enable
      service.chronyd=stop,disable
    name: performance-patch
  recommend:
  - machineConfigLabels:
      machineconfiguration.openshift.io/role: master
    priority: 19
    profile: performance-patch

1: The cpu list in cmdline=nohz_full= will vary based on your hardware configuration.

Check that cluster networking diagnostics are disabled by running the following command:
```
$ oc get networks.operator.openshift.io cluster -o jsonpath='{.spec.disableNetworkDiagnostics}'
```
Example output
```
true
```

Check that the Kubelet housekeeping interval is tuned to slower rate. This is set in the containerMountNS machine config. Run the following command:

$ oc describe machineconfig container-mount-namespace-and-kubelet-conf-master | grep OPENSHIFT_MAX_HOUSEKEEPING_INTERVAL_DURATION

Example output

Environment="OPENSHIFT_MAX_HOUSEKEEPING_INTERVAL_DURATION=60s"

Check that Grafana and alertManagerMain are disabled and that the Prometheus retention period is set to 24h by running the following command:
```
$ oc get configmap cluster-monitoring-config -n openshift-monitoring -o jsonpath="{ .data.config\.yaml }"
```
Example output
```
grafana:
  enabled: false
alertmanagerMain:
  enabled: false
prometheusK8s:
   retention: 24h
```
1. Use the following commands to verify that Grafana and alertManagerMain routes are not found in the cluster:
```
$ oc get route -n openshift-monitoring alertmanager-main
```
```
$ oc get route -n openshift-monitoring grafana
```
  Both queries should return Error from server (NotFound) messages.
Check that there is a minimum of 4 CPUs allocated as reserved for each of the PerformanceProfile, Tuned performance-patch, workload partitioning, and kernel command line arguments by running the following command:
```
$ oc get performanceprofile -o jsonpath="{ .items[0].spec.cpu.reserved }"
```
Example output
```
0-3
```
Note
Depending on your workload requirements, you might require additional reserved CPUs to be allocated.

18.9. Advanced managed cluster configuration with SiteConfig resources

You can use SiteConfig custom resources (CRs) to deploy custom functionality and configurations in your managed clusters at installation time.

18.9.1. Customizing extra installation manifests in the GitOps ZTP pipeline

You can define a set of extra manifests for inclusion in the installation phase of the GitOps Zero Touch Provisioning (ZTP) pipeline. These manifests are linked to the SiteConfig custom resources (CRs) and are applied to the cluster during installation. Including MachineConfig CRs at install time makes the installation process more efficient.

Prerequisites

Create a Git repository where you manage your custom site configuration data. The repository must be accessible from the hub cluster and be defined as a source repository for the Argo CD application.

Procedure

Create a set of extra manifest CRs that the GitOps ZTP pipeline uses to customize the cluster installs.
In your custom /siteconfig directory, create a subdirectory /custom-manifest for your extra manifests. The following example illustrates a sample /siteconfig with /custom-manifest folder:
```
siteconfig
├── site1-sno-du.yaml
├── site2-standard-du.yaml
├── extra-manifest/
└── custom-manifest
    └── 01-example-machine-config.yaml
```
Note
The subdirectory names /custom-manifest and /extra-manifest used throughout are example names only. There is no requirement to use these names and no restriction on how you name these subdirectories. In this example /extra-manifest refers to the Git subdirectory that stores the contents of /extra-manifest from the ztp-site-generate container.
Add your custom extra manifest CRs to the siteconfig/custom-manifest directory.
In your SiteConfig CR, enter the directory name in the extraManifests.searchPaths field, for example:
```
clusters:
- clusterName: "example-sno"
  networkType: "OVNKubernetes"
  extraManifests:
    searchPaths:
      - extra-manifest/ 1
      - custom-manifest/ 2
```
1
Folder for manifests copied from the ztp-site-generate container.
2
Folder for custom manifests.
Save the SiteConfig, /extra-manifest, and /custom-manifest CRs, and push them to the site configuration repo.

During cluster provisioning, the GitOps ZTP pipeline appends the CRs in the /custom-manifest directory to the default set of extra manifests stored in extra-manifest/.

Note

As of version 4.14 extraManifestPath is subject to a deprecation warning.

While extraManifestPath is still supported, we recommend that you use extraManifests.searchPaths. If you define extraManifests.searchPaths in the SiteConfig file, the GitOps ZTP pipeline does not fetch manifests from the ztp-site-generate container during site installation.

If you define both extraManifestPath and extraManifests.searchPaths in the Siteconfig CR, the setting defined for extraManifests.searchPaths takes precedence.

It is strongly recommended that you extract the contents of /extra-manifest from the ztp-site-generate container and push it to the GIT repository.

18.9.2. Filtering custom resources using SiteConfig filters

By using filters, you can easily customize SiteConfig custom resources (CRs) to include or exclude other CRs for use in the installation phase of the GitOps Zero Touch Provisioning (ZTP) pipeline.

You can specify an inclusionDefault value of include or exclude for the SiteConfig CR, along with a list of the specific extraManifest RAN CRs that you want to include or exclude. Setting inclusionDefault to include makes the GitOps ZTP pipeline apply all the files in /source-crs/extra-manifest during installation. Setting inclusionDefault to exclude does the opposite.

You can exclude individual CRs from the /source-crs/extra-manifest folder that are otherwise included by default. The following example configures a custom single-node OpenShift SiteConfig CR to exclude the /source-crs/extra-manifest/03-sctp-machine-config-worker.yaml CR at installation time.

Some additional optional filtering scenarios are also described.

Prerequisites

You configured the hub cluster for generating the required installation and policy CRs.
You created a Git repository where you manage your custom site configuration data. The repository must be accessible from the hub cluster and be defined as a source repository for the Argo CD application.

Procedure

To prevent the GitOps ZTP pipeline from applying the 03-sctp-machine-config-worker.yaml CR file, apply the following YAML in the SiteConfig CR:

apiVersion: ran.openshift.io/v1
kind: SiteConfig
metadata:
  name: "site1-sno-du"
  namespace: "site1-sno-du"
spec:
  baseDomain: "example.com"
  pullSecretRef:
    name: "assisted-deployment-pull-secret"
  clusterImageSetNameRef: "openshift-4.14"
  sshPublicKey: "<ssh_public_key>"
  clusters:
- clusterName: "site1-sno-du"
  extraManifests:
    filter:
      exclude:
        - 03-sctp-machine-config-worker.yaml

The GitOps ZTP pipeline skips the 03-sctp-machine-config-worker.yaml CR during installation. All other CRs in /source-crs/extra-manifest are applied.

Save the SiteConfig CR and push the changes to the site configuration repository.
The GitOps ZTP pipeline monitors and adjusts what CRs it applies based on the SiteConfig filter instructions.
Optional: To prevent the GitOps ZTP pipeline from applying all the /source-crs/extra-manifest CRs during cluster installation, apply the following YAML in the SiteConfig CR:
```
- clusterName: "site1-sno-du"
  extraManifests:
    filter:
      inclusionDefault: exclude
```
Optional: To exclude all the /source-crs/extra-manifest RAN CRs and instead include a custom CR file during installation, edit the custom SiteConfig CR to set the custom manifests folder and the include file, for example:
```
clusters:
- clusterName: "site1-sno-du"
  extraManifestPath: "<custom_manifest_folder>" 1
  extraManifests:
    filter:
      inclusionDefault: exclude  2
      include:
        - custom-sctp-machine-config-worker.yaml
```
1
Replace <custom_manifest_folder> with the name of the folder that contains the custom installation CRs, for example, user-custom-manifest/.
2
Set inclusionDefault to exclude to prevent the GitOps ZTP pipeline from applying the files in /source-crs/extra-manifest during installation.
The following example illustrates the custom folder structure:
```
siteconfig
  ├── site1-sno-du.yaml
  └── user-custom-manifest
        └── custom-sctp-machine-config-worker.yaml
```

18.9.3. Deleting a node by using the SiteConfig CR

By using a SiteConfig custom resource (CR), you can delete and reprovision a node. This method is more efficient than manually deleting the node.

Prerequisites

You have configured the hub cluster to generate the required installation and policy CRs.
You have created a Git repository in which you can manage your custom site configuration data. The repository must be accessible from the hub cluster and be defined as the source repository for the Argo CD application.

Procedure

Update the SiteConfig CR to include the bmac.agent-install.openshift.io/remove-agent-and-node-on-delete=true annotation and push the changes to the Git repository:

apiVersion: ran.openshift.io/v1
kind: SiteConfig
metadata:
  name: "cnfdf20"
  namespace: "cnfdf20"
spec:
  clusters:
    nodes:
    - hostname: node6
      role: "worker"
      crAnnotations:
        add:
          BareMetalHost:
            bmac.agent-install.openshift.io/remove-agent-and-node-on-delete: true
# ...

Verify that the BareMetalHost object is annotated by running the following command:

oc get bmh -n <managed-cluster-namespace> <bmh-object> -ojsonpath='{.metadata}' | jq -r '.annotations["bmac.agent-install.openshift.io/remove-agent-and-node-on-delete"]'

Example output

true

Suppress the generation of the BareMetalHost CR by updating the SiteConfig CR to include the crSuppression.BareMetalHost annotation:

apiVersion: ran.openshift.io/v1
kind: SiteConfig
metadata:
  name: "cnfdf20"
  namespace: "cnfdf20"
spec:
  clusters:
  - nodes:
    - hostName: node6
      role: "worker"
      crSuppression:
      - BareMetalHost
# ...

Push the changes to the Git repository and wait for deprovisioning to start. The status of the BareMetalHost CR should change to deprovisioning. Wait for the BareMetalHost to finish deprovisioning, and be fully deleted.

Verification

Verify that the BareMetalHost and Agent CRs for the worker node have been deleted from the hub cluster by running the following commands:
```
$ oc get bmh -n <cluster-ns>
```
```
$ oc get agent -n <cluster-ns>
```
Verify that the node record has been deleted from the spoke cluster by running the following command:
```
$ oc get nodes
```
Note
If you are working with secrets, deleting a secret too early can cause an issue because ArgoCD needs the secret to complete resynchronization after deletion. Delete the secret only after the node cleanup, when the current ArgoCD synchronization is complete.

Next Steps

To reprovision a node, delete the changes previously added to the SiteConfig, push the changes to the Git repository, and wait for the synchronization to complete. This regenerates the BareMetalHost CR of the worker node and triggers the re-install of the node.

18.10. Advanced managed cluster configuration with PolicyGenTemplate resources

You can use PolicyGenTemplate CRs to deploy custom functionality in your managed clusters.

18.10.1. Deploying additional changes to clusters

If you require cluster configuration changes outside of the base GitOps Zero Touch Provisioning (ZTP) pipeline configuration, there are three options:

Apply the additional configuration after the GitOps ZTP pipeline is complete: When the GitOps ZTP pipeline deployment is complete, the deployed cluster is ready for application workloads. At this point, you can install additional Operators and apply configurations specific to your requirements. Ensure that additional configurations do not negatively affect the performance of the platform or allocated CPU budget.
Add content to the GitOps ZTP library: The base source custom resources (CRs) that you deploy with the GitOps ZTP pipeline can be augmented with custom content as required.
Create extra manifests for the cluster installation: Extra manifests are applied during installation and make the installation process more efficient.

Important

Providing additional source CRs or modifying existing source CRs can significantly impact the performance or CPU profile of OpenShift Container Platform.

Additional resources

Customizing extra installation manifests in the GitOps ZTP pipeline

18.10.2. Using PolicyGenTemplate CRs to override source CRs content

PolicyGenTemplate custom resources (CRs) allow you to overlay additional configuration details on top of the base source CRs provided with the GitOps plugin in the ztp-site-generate container. You can think of PolicyGenTemplate CRs as a logical merge or patch to the base CR. Use PolicyGenTemplate CRs to update a single field of the base CR, or overlay the entire contents of the base CR. You can update values and insert fields that are not in the base CR.

The following example procedure describes how to update fields in the generated PerformanceProfile CR for the reference configuration based on the PolicyGenTemplate CR in the group-du-sno-ranGen.yaml file. Use the procedure as a basis for modifying other parts of the PolicyGenTemplate based on your requirements.

Prerequisites

Create a Git repository where you manage your custom site configuration data. The repository must be accessible from the hub cluster and be defined as a source repository for Argo CD.

Procedure

Review the baseline source CR for existing content. You can review the source CRs listed in the reference PolicyGenTemplate CRs by extracting them from the GitOps Zero Touch Provisioning (ZTP) container.
1. Create an /out folder:
```
$ mkdir -p ./out
```
2. Extract the source CRs:
```
$ podman run --log-driver=none --rm registry.redhat.io/openshift4/ztp-site-generate-rhel8:v4.14.1 extract /home/ztp --tar | tar x -C ./out
```

Review the baseline PerformanceProfile CR in ./out/source-crs/PerformanceProfile.yaml:

apiVersion: performance.openshift.io/v2
kind: PerformanceProfile
metadata:
  name: $name
  annotations:
    ran.openshift.io/ztp-deploy-wave: "10"
spec:
  additionalKernelArgs:
  - "idle=poll"
  - "rcupdate.rcu_normal_after_boot=0"
  cpu:
    isolated: $isolated
    reserved: $reserved
  hugepages:
    defaultHugepagesSize: $defaultHugepagesSize
    pages:
      - size: $size
        count: $count
        node: $node
  machineConfigPoolSelector:
    pools.operator.machineconfiguration.openshift.io/$mcp: ""
  net:
    userLevelNetworking: true
  nodeSelector:
    node-role.kubernetes.io/$mcp: ''
  numa:
    topologyPolicy: "restricted"
  realTimeKernel:
    enabled: true

Note

Any fields in the source CR which contain $… are removed from the generated CR if they are not provided in the PolicyGenTemplate CR.

Update the PolicyGenTemplate entry for PerformanceProfile in the group-du-sno-ranGen.yaml reference file. The following example PolicyGenTemplate CR stanza supplies appropriate CPU specifications, sets the hugepages configuration, and adds a new field that sets globallyDisableIrqLoadBalancing to false.

- fileName: PerformanceProfile.yaml
  policyName: "config-policy"
  metadata:
    name: openshift-node-performance-profile
  spec:
    cpu:
      # These must be tailored for the specific hardware platform
      isolated: "2-19,22-39"
      reserved: "0-1,20-21"
    hugepages:
      defaultHugepagesSize: 1G
      pages:
        - size: 1G
          count: 10
    globallyDisableIrqLoadBalancing: false

Commit the PolicyGenTemplate change in Git, and then push to the Git repository being monitored by the GitOps ZTP argo CD application.

Example output

The GitOps ZTP application generates an RHACM policy that contains the generated PerformanceProfile CR. The contents of that CR are derived by merging the metadata and spec contents from the PerformanceProfile entry in the PolicyGenTemplate onto the source CR. The resulting CR has the following content:

---
apiVersion: performance.openshift.io/v2
kind: PerformanceProfile
metadata:
    name: openshift-node-performance-profile
spec:
    additionalKernelArgs:
        - idle=poll
        - rcupdate.rcu_normal_after_boot=0
    cpu:
        isolated: 2-19,22-39
        reserved: 0-1,20-21
    globallyDisableIrqLoadBalancing: false
    hugepages:
        defaultHugepagesSize: 1G
        pages:
            - count: 10
              size: 1G
    machineConfigPoolSelector:
        pools.operator.machineconfiguration.openshift.io/master: ""
    net:
        userLevelNetworking: true
    nodeSelector:
        node-role.kubernetes.io/master: ""
    numa:
        topologyPolicy: restricted
    realTimeKernel:
        enabled: true

Note

In the /source-crs folder that you extract from the ztp-site-generate container, the $ syntax is not used for template substitution as implied by the syntax. Rather, if the policyGen tool sees the $ prefix for a string and you do not specify a value for that field in the related PolicyGenTemplate CR, the field is omitted from the output CR entirely.

An exception to this is the $mcp variable in /source-crs YAML files that is substituted with the specified value for mcp from the PolicyGenTemplate CR. For example, in example/policygentemplates/group-du-standard-ranGen.yaml, the value for mcp is worker:

spec:
  bindingRules:
    group-du-standard: ""
  mcp: "worker"

The policyGen tool replace instances of $mcp with worker in the output CRs.

18.10.3. Adding custom content to the GitOps ZTP pipeline

Perform the following procedure to add new content to the GitOps ZTP pipeline.

Procedure

Create a subdirectory named source-crs in the directory that contains the kustomization.yaml file for the PolicyGenTemplate custom resource (CR).

Add your user-provided CRs to the source-crs subdirectory, as shown in the following example:

example
└── policygentemplates
    ├── dev.yaml
    ├── kustomization.yaml
    ├── mec-edge-sno1.yaml
    ├── sno.yaml
    └── source-crs 1
        ├── PaoCatalogSource.yaml
        ├── PaoSubscription.yaml
        ├── custom-crs
        |   ├── apiserver-config.yaml
        |   └── disable-nic-lldp.yaml
        └── elasticsearch
            ├── ElasticsearchNS.yaml
            └── ElasticsearchOperatorGroup.yaml

1: The source-crs subdirectory must be in the same directory as the kustomization.yaml file.

Update the required PolicyGenTemplate CRs to include references to the content you added in the source-crs/custom-crs and source-crs/elasticsearch directories. For example:

apiVersion: ran.openshift.io/v1
kind: PolicyGenTemplate
metadata:
  name: "group-dev"
  namespace: "ztp-clusters"
spec:
  bindingRules:
    dev: "true"
  mcp: "master"
  sourceFiles:
    # These policies/CRs come from the internal container Image
    #Cluster Logging
    - fileName: ClusterLogNS.yaml
      remediationAction: inform
      policyName: "group-dev-cluster-log-ns"
    - fileName: ClusterLogOperGroup.yaml
      remediationAction: inform
      policyName: "group-dev-cluster-log-operator-group"
    - fileName: ClusterLogSubscription.yaml
      remediationAction: inform
      policyName: "group-dev-cluster-log-sub"
    #Local Storage Operator
    - fileName: StorageNS.yaml
      remediationAction: inform
      policyName: "group-dev-lso-ns"
    - fileName: StorageOperGroup.yaml
      remediationAction: inform
      policyName: "group-dev-lso-operator-group"
    - fileName: StorageSubscription.yaml
      remediationAction: inform
      policyName: "group-dev-lso-sub"
    #These are custom local polices that come from the source-crs directory in the git repo
    # Performance Addon Operator
    - fileName: PaoSubscriptionNS.yaml
      remediationAction: inform
      policyName: "group-dev-pao-ns"
    - fileName: PaoSubscriptionCatalogSource.yaml
      remediationAction: inform
      policyName: "group-dev-pao-cat-source"
      spec:
        image: <image_URL_here>
    - fileName: PaoSubscription.yaml
      remediationAction: inform
      policyName: "group-dev-pao-sub"
    #Elasticsearch Operator
    - fileName: elasticsearch/ElasticsearchNS.yaml 1
      remediationAction: inform
      policyName: "group-dev-elasticsearch-ns"
    - fileName: elasticsearch/ElasticsearchOperatorGroup.yaml
      remediationAction: inform
      policyName: "group-dev-elasticsearch-operator-group"
    #Custom Resources
    - fileName: custom-crs/apiserver-config.yaml 2
      remediationAction: inform
      policyName: "group-dev-apiserver-config"
    - fileName: custom-crs/disable-nic-lldp.yaml
      remediationAction: inform
      policyName: "group-dev-disable-nic-lldp"

1 2: Set fileName to include the relative path to the file from the /source-crs parent directory.

Commit the PolicyGenTemplate change in Git, and then push to the Git repository that is monitored by the GitOps ZTP Argo CD policies application.

Update the ClusterGroupUpgrade CR to include the changed PolicyGenTemplate and save it as cgu-test.yaml. The following example shows a generated cgu-test.yaml file.

apiVersion: ran.openshift.io/v1alpha1
kind: ClusterGroupUpgrade
metadata:
  name: custom-source-cr
  namespace: ztp-clusters
spec:
  managedPolicies:
    - group-dev-config-policy
  enable: true
  clusters:
  - cluster1
  remediationStrategy:
    maxConcurrency: 2
    timeout: 240

Apply the updated ClusterGroupUpgrade CR by running the following command:
```
$ oc apply -f cgu-test.yaml
```

Verification

Check that the updates have succeeded by running the following command:

$ oc get cgu -A

Example output

NAMESPACE     NAME               AGE   STATE        DETAILS
ztp-clusters  custom-source-cr   6s    InProgress   Remediating non-compliant policies
ztp-install   cluster1           19h   Completed    All clusters are compliant with all the managed policies

18.10.4. Configuring policy compliance evaluation timeouts for PolicyGenTemplate CRs

Use Red Hat Advanced Cluster Management (RHACM) installed on a hub cluster to monitor and report on whether your managed clusters are compliant with applied policies. RHACM uses policy templates to apply predefined policy controllers and policies. Policy controllers are Kubernetes custom resource definition (CRD) instances.

You can override the default policy evaluation intervals with PolicyGenTemplate custom resources (CRs). You configure duration settings that define how long a ConfigurationPolicy CR can be in a state of policy compliance or non-compliance before RHACM re-evaluates the applied cluster policies.

The GitOps Zero Touch Provisioning (ZTP) policy generator generates ConfigurationPolicy CR policies with pre-defined policy evaluation intervals. The default value for the noncompliant state is 10 seconds. The default value for the compliant state is 10 minutes. To disable the evaluation interval, set the value to never.

Prerequisites

You have installed the OpenShift CLI (oc).
You have logged in to the hub cluster as a user with cluster-admin privileges.
You have created a Git repository where you manage your custom site configuration data.

Procedure

To configure the evaluation interval for all policies in a PolicyGenTemplate CR, add evaluationInterval to the spec field, and then set the appropriate compliant and noncompliant values. For example:
```
spec:
  evaluationInterval:
    compliant: 30m
    noncompliant: 20s
```

To configure the evaluation interval for the spec.sourceFiles object in a PolicyGenTemplate CR, add evaluationInterval to the sourceFiles field, for example:

spec:
  sourceFiles:
   - fileName: SriovSubscription.yaml
     policyName: "sriov-sub-policy"
     evaluationInterval:
       compliant: never
       noncompliant: 10s

Commit the PolicyGenTemplate CRs files in the Git repository and push your changes.

Verification

Check that the managed spoke cluster policies are monitored at the expected intervals.

Get the pods that are running in the open-cluster-management-agent-addon namespace. Run the following command:

$ oc get pods -n open-cluster-management-agent-addon

Example output

NAME                                         READY   STATUS    RESTARTS        AGE
config-policy-controller-858b894c68-v4xdb    1/1     Running   22 (5d8h ago)   10d

Check the applied policies are being evaluated at the expected interval in the logs for the config-policy-controller pod:

$ oc logs -n open-cluster-management-agent-addon config-policy-controller-858b894c68-v4xdb

Example output

2022-05-10T15:10:25.280Z       info   configuration-policy-controller controllers/configurationpolicy_controller.go:166      Skipping the policy evaluation due to the policy not reaching the evaluation interval  {"policy": "compute-1-config-policy-config"}
2022-05-10T15:10:25.280Z       info   configuration-policy-controller controllers/configurationpolicy_controller.go:166      Skipping the policy evaluation due to the policy not reaching the evaluation interval  {"policy": "compute-1-common-compute-1-catalog-policy-config"}

18.10.5. Signalling GitOps ZTP cluster deployment completion with validator inform policies

Create a validator inform policy that signals when the GitOps Zero Touch Provisioning (ZTP) installation and configuration of the deployed cluster is complete. This policy can be used for deployments of single-node OpenShift clusters, three-node clusters, and standard clusters.

Procedure

Create a standalone PolicyGenTemplate custom resource (CR) that contains the source file validatorCRs/informDuValidator.yaml. You only need one standalone PolicyGenTemplate CR for each cluster type. For example, this CR applies a validator inform policy for single-node OpenShift clusters:
Example single-node cluster validator inform policy CR (group-du-sno-validator-ranGen.yaml)
```
apiVersion: ran.openshift.io/v1
kind: PolicyGenTemplate
metadata:
  name: "group-du-sno-validator" 1
  namespace: "ztp-group" 2
spec:
  bindingRules:
    group-du-sno: "" 3
  bindingExcludedRules:
    ztp-done: "" 4
  mcp: "master" 5
  sourceFiles:
    - fileName: validatorCRs/informDuValidator.yaml
      remediationAction: inform 6
      policyName: "du-policy" 7
```
1
The name of PolicyGenTemplates object. This name is also used as part of the names for the placementBinding, placementRule, and policy that are created in the requested namespace.
2
This value should match the namespace used in the group PolicyGenTemplates.
3
The group-du-* label defined in bindingRules must exist in the SiteConfig files.
4
The label defined in bindingExcludedRules must be`ztp-done:`. The ztp-done label is used in coordination with the Topology Aware Lifecycle Manager.
5
mcp defines the MachineConfigPool object that is used in the source file validatorCRs/informDuValidator.yaml. It should be master for single node and three-node cluster deployments and worker for standard cluster deployments.
6
Optional. The default value is inform.
7
This value is used as part of the name for the generated RHACM policy. The generated validator policy for the single node example is group-du-sno-validator-du-policy.
Commit the PolicyGenTemplate CR file in your Git repository and push the changes.

Additional resources

Upgrading GitOps ZTP

18.10.6. Configuring power states using PolicyGenTemplates CRs

For low latency and high-performance edge deployments, it is necessary to disable or limit C-states and P-states. With this configuration, the CPU runs at a constant frequency, which is typically the maximum turbo frequency. This ensures that the CPU is always running at its maximum speed, which results in high performance and low latency. This leads to the best latency for workloads. However, this also leads to the highest power consumption, which might not be necessary for all workloads.

Workloads can be classified as critical or non-critical, with critical workloads requiring disabled C-state and P-state settings for high performance and low latency, while non-critical workloads use C-state and P-state settings for power savings at the expense of some latency and performance. You can configure the following three power states using GitOps Zero Touch Provisioning (ZTP):

High-performance mode provides ultra low latency at the highest power consumption.
Performance mode provides low latency at a relatively high power consumption.
Power saving balances reduced power consumption with increased latency.

The default configuration is for a low latency, performance mode.

PolicyGenTemplate custom resources (CRs) allow you to overlay additional configuration details onto the base source CRs provided with the GitOps plugin in the ztp-site-generate container.

Configure the power states by updating the workloadHints fields in the generated PerformanceProfile CR for the reference configuration, based on the PolicyGenTemplate CR in the group-du-sno-ranGen.yaml.

The following common prerequisites apply to configuring all three power states.

Prerequisites

You have created a Git repository where you manage your custom site configuration data. The repository must be accessible from the hub cluster and be defined as a source repository for Argo CD.
You have followed the procedure described in "Preparing the GitOps ZTP site configuration repository".

Additional resources

Configuring node power consumption and realtime processing with workload hints

18.10.6.1. Configuring performance mode using PolicyGenTemplate CRs

Follow this example to set performance mode by updating the workloadHints fields in the generated PerformanceProfile CR for the reference configuration, based on the PolicyGenTemplate CR in the group-du-sno-ranGen.yaml.

Performance mode provides low latency at a relatively high power consumption.

Prerequisites

You have configured the BIOS with performance related settings by following the guidance in "Configuring host firmware for low latency and high performance".

Procedure

Update the PolicyGenTemplate entry for PerformanceProfile in the group-du-sno-ranGen.yaml reference file in out/argocd/example/policygentemplates as follows to set performance mode.

- fileName: PerformanceProfile.yaml
  policyName: "config-policy"
  metadata:
    [...]
  spec:
    [...]
    workloadHints:
         realTime: true
         highPowerConsumption: false
         perPodPowerManagement: false

Commit the PolicyGenTemplate change in Git, and then push to the Git repository being monitored by the GitOps ZTP Argo CD application.

18.10.6.2. Configuring high-performance mode using PolicyGenTemplate CRs

Follow this example to set high performance mode by updating the workloadHints fields in the generated PerformanceProfile CR for the reference configuration, based on the PolicyGenTemplate CR in the group-du-sno-ranGen.yaml.

High performance mode provides ultra low latency at the highest power consumption.

Prerequisites

You have configured the BIOS with performance related settings by following the guidance in "Configuring host firmware for low latency and high performance".

Procedure

Update the PolicyGenTemplate entry for PerformanceProfile in the group-du-sno-ranGen.yaml reference file in out/argocd/example/policygentemplates as follows to set high-performance mode.

- fileName: PerformanceProfile.yaml
  policyName: "config-policy"
  metadata:
    [...]
  spec:
    [...]
    workloadHints:
         realTime: true
         highPowerConsumption: true
         perPodPowerManagement: false

Commit the PolicyGenTemplate change in Git, and then push to the Git repository being monitored by the GitOps ZTP Argo CD application.

18.10.6.3. Configuring power saving mode using PolicyGenTemplate CRs

Follow this example to set power saving mode by updating the workloadHints fields in the generated PerformanceProfile CR for the reference configuration, based on the PolicyGenTemplate CR in the group-du-sno-ranGen.yaml.

The power saving mode balances reduced power consumption with increased latency.

Prerequisites

You enabled C-states and OS-controlled P-states in the BIOS.

Procedure

Update the PolicyGenTemplate entry for PerformanceProfile in the group-du-sno-ranGen.yaml reference file in out/argocd/example/policygentemplates as follows to configure power saving mode. It is recommended to configure the CPU governor for the power saving mode through the additional kernel arguments object.
```
- fileName: PerformanceProfile.yaml
  policyName: "config-policy"
  metadata:
    [...]
  spec:
    [...]
    workloadHints:
         realTime: true
         highPowerConsumption: false
         perPodPowerManagement: true
    [...]
    additionalKernelArgs:
       - [...]
       - "cpufreq.default_governor=schedutil" 1
```
1
The schedutil governor is recommended, however, other governors that can be used include ondemand and powersave.
Commit the PolicyGenTemplate change in Git, and then push to the Git repository being monitored by the GitOps ZTP Argo CD application.

Verification

Select a worker node in your deployed cluster from the list of nodes identified by using the following command:
```
$ oc get nodes
```
Log in to the node by using the following command:
```
$ oc debug node/<node-name>
```
Replace <node-name> with the name of the node you want to verify the power state on.
Set /host as the root directory within the debug shell. The debug pod mounts the host’s root file system in /host within the pod. By changing the root directory to /host, you can run binaries contained in the host’s executable paths as shown in the following example:
```
# chroot /host
```
Run the following command to verify the applied power state:
```
# cat /proc/cmdline
```

Expected output

For power saving mode the intel_pstate=passive.

Additional resources

Configuring power saving for nodes that run colocated high and low priority workloads
Configuring host firmware for low latency and high performance
Preparing the GitOps ZTP site configuration repository

18.10.6.4. Maximizing power savings

Limiting the maximum CPU frequency is recommended to achieve maximum power savings. Enabling C-states on the non-critical workload CPUs without restricting the maximum CPU frequency negates much of the power savings by boosting the frequency of the critical CPUs.

Maximize power savings by updating the sysfs plugin fields, setting an appropriate value for max_perf_pct in the TunedPerformancePatch CR for the reference configuration. This example based on the group-du-sno-ranGen.yaml describes the procedure to follow to restrict the maximum CPU frequency.

Prerequisites

You have configured power savings mode as described in "Using PolicyGenTemplate CRs to configure power savings mode".

Procedure

Update the PolicyGenTemplate entry for TunedPerformancePatch in the group-du-sno-ranGen.yaml reference file in out/argocd/example/policygentemplates. To maximize power savings, add max_perf_pct as shown in the following example:
```
- fileName: TunedPerformancePatch.yaml
      policyName: "config-policy"
      spec:
        profile:
          - name: performance-patch
            data: |
              [...]
              [sysfs]
              /sys/devices/system/cpu/intel_pstate/max_perf_pct=<x> 1
```
1
The max_perf_pct controls the maximum frequency the cpufreq driver is allowed to set as a percentage of the maximum supported CPU frequency. This value applies to all CPUs. You can check the maximum supported frequency in /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq. As a starting point, you can use a percentage that caps all CPUs at the All Cores Turbo frequency. The All Cores Turbo frequency is the frequency that all cores will run at when the cores are all fully occupied.
Note
To maximize power savings, set a lower value. Setting a lower value for max_perf_pct limits the maximum CPU frequency, thereby reducing power consumption, but also potentially impacting performance. Experiment with different values and monitor the system’s performance and power consumption to find the optimal setting for your use-case.
Commit the PolicyGenTemplate change in Git, and then push to the Git repository being monitored by the GitOps ZTP Argo CD application.

18.10.7. Configuring LVM Storage using PolicyGenTemplate CRs

You can configure Logical Volume Manager (LVM) Storage for managed clusters that you deploy with GitOps Zero Touch Provisioning (ZTP).

Note

You use LVM Storage to persist event subscriptions when you use PTP events or bare-metal hardware events with HTTP transport.

Use the Local Storage Operator for persistent storage that uses local volumes in distributed units.

Prerequisites

Install the OpenShift CLI (oc).
Log in as a user with cluster-admin privileges.
Create a Git repository where you manage your custom site configuration data.

Procedure

To configure LVM Storage for new managed clusters, add the following YAML to spec.sourceFiles in the common-ranGen.yaml file:
```
- fileName: StorageLVMOSubscriptionNS.yaml
  policyName: subscription-policies
- fileName: StorageLVMOSubscriptionOperGroup.yaml
  policyName: subscription-policies
- fileName: StorageLVMOSubscription.yaml
  spec:
    name: lvms-operator
    channel: stable-4.14
  policyName: subscription-policies
```
Note
The Storage LVMO subscription is deprecated. In future releases of OpenShift Container Platform, the storage LVMO subscription will not be available. Instead, you must use the Storage LVMS subscription.
In OpenShift Container Platform 4.14, you can use the Storage LVMS subscription instead of the LVMO subscription. The LVMS subscription does not require manual overrides in the common-ranGen.yaml file. Add the following YAML to spec.sourceFiles in the common-ranGen.yaml file to use the Storage LVMS subscription:
```
- fileName: StorageLVMSubscriptionNS.yaml
  policyName: subscription-policies
- fileName: StorageLVMSubscriptionOperGroup.yaml
  policyName: subscription-policies
- fileName: StorageLVMSubscription.yaml
  policyName: subscription-policies
```
Add the LVMCluster CR to spec.sourceFiles in your specific group or individual site configuration file. For example, in the group-du-sno-ranGen.yaml file, add the following:
```
- fileName: StorageLVMCluster.yaml
  policyName: "lvms-config" 1
  spec:
    storage:
      deviceClasses:
      - name: vg1
        thinPoolConfig:
          name: thin-pool-1
          sizePercent: 90
          overprovisionRatio: 10
```
1
This example configuration creates a volume group (vg1) with all the available devices, except the disk where OpenShift Container Platform is installed. A thin-pool logical volume is also created.
Merge any other required changes and files with your custom site repository.
Commit the PolicyGenTemplate changes in Git, and then push the changes to your site configuration repository to deploy LVM Storage to new sites using GitOps ZTP.

18.10.8. Configuring PTP events with PolicyGenTemplate CRs

You can use the GitOps ZTP pipeline to configure PTP events that use HTTP or AMQP transport.

Note

18.10.8.1. Configuring PTP events that use HTTP transport

You can configure PTP events that use HTTP transport on managed clusters that you deploy with the GitOps Zero Touch Provisioning (ZTP) pipeline.

Prerequisites

You have installed the OpenShift CLI (oc).
You have logged in as a user with cluster-admin privileges.
You have created a Git repository where you manage your custom site configuration data.

Procedure

Apply the following PolicyGenTemplate changes to group-du-3node-ranGen.yaml, group-du-sno-ranGen.yaml, or group-du-standard-ranGen.yaml files according to your requirements:
1. In .sourceFiles, add the PtpOperatorConfig CR file that configures the transport host:
```
- fileName: PtpOperatorConfigForEvent.yaml
  policyName: "config-policy"
  spec:
    daemonNodeSelector: {}
    ptpEventConfig:
      enableEventPublisher: true
      transportHost: http://ptp-event-publisher-service-NODE_NAME.openshift-ptp.svc.cluster.local:9043
```
  Note
  In OpenShift Container Platform 4.13 or later, you do not need to set the transportHost field in the PtpOperatorConfig resource when you use HTTP transport with PTP events.
2. Configure the linuxptp and phc2sys for the PTP clock type and interface. For example, add the following stanza into .sourceFiles:
```
- fileName: PtpConfigSlave.yaml 1
  policyName: "config-policy"
  metadata:
    name: "du-ptp-slave"
  spec:
    profile:
    - name: "slave"
      interface: "ens5f1" 2
      ptp4lOpts: "-2 -s --summary_interval -4" 3
      phc2sysOpts: "-a -r -m -n 24 -N 8 -R 16" 4
    ptpClockThreshold: 5
      holdOverTimeout: 30 #secs
      maxOffsetThreshold: 100  #nano secs
      minOffsetThreshold: -100 #nano secs
```
  1
  Can be PtpConfigMaster.yaml or PtpConfigSlave.yaml depending on your requirements. For configurations based on group-du-sno-ranGen.yaml or group-du-3node-ranGen.yaml, use PtpConfigSlave.yaml.
  2
  Device specific interface name.
  3
  You must append the --summary_interval -4 value to ptp4lOpts in .spec.sourceFiles.spec.profile to enable PTP fast events.
  4
  Required phc2sysOpts values. -m prints messages to stdout. The linuxptp-daemon DaemonSet parses the logs and generates Prometheus metrics.
  5
  Optional. If the ptpClockThreshold stanza is not present, default values are used for the ptpClockThreshold fields. The stanza shows default ptpClockThreshold values. The ptpClockThreshold values configure how long after the PTP master clock is disconnected before PTP events are triggered. holdOverTimeout is the time value in seconds before the PTP clock event state changes to FREERUN when the PTP master clock is disconnected. The maxOffsetThreshold and minOffsetThreshold settings configure offset values in nanoseconds that compare against the values for CLOCK_REALTIME (phc2sys) or master offset (ptp4l). When the ptp4l or phc2sys offset value is outside this range, the PTP clock state is set to FREERUN. When the offset value is within this range, the PTP clock state is set to LOCKED.
Merge any other required changes and files with your custom site repository.
Push the changes to your site configuration repository to deploy PTP fast events to new sites using GitOps ZTP.

Additional resources

Using PolicyGenTemplate CRs to override source CRs content

18.10.8.2. Configuring PTP events that use AMQP transport

You can configure PTP events that use AMQP transport on managed clusters that you deploy with the GitOps Zero Touch Provisioning (ZTP) pipeline.

Note

Prerequisites

You have installed the OpenShift CLI (oc).
You have logged in as a user with cluster-admin privileges.
You have created a Git repository where you manage your custom site configuration data.

Procedure

Add the following YAML into .spec.sourceFiles in the common-ranGen.yaml file to configure the AMQP Operator:

#AMQ interconnect operator for fast events
- fileName: AmqSubscriptionNS.yaml
  policyName: "subscriptions-policy"
- fileName: AmqSubscriptionOperGroup.yaml
  policyName: "subscriptions-policy"
- fileName: AmqSubscription.yaml
  policyName: "subscriptions-policy"

Apply the following PolicyGenTemplate changes to group-du-3node-ranGen.yaml, group-du-sno-ranGen.yaml, or group-du-standard-ranGen.yaml files according to your requirements:
1. In .sourceFiles, add the PtpOperatorConfig CR file that configures the AMQ transport host to the config-policy:
```
- fileName: PtpOperatorConfigForEvent.yaml
  policyName: "config-policy"
  spec:
    daemonNodeSelector: {}
    ptpEventConfig:
      enableEventPublisher: true
      transportHost: "amqp://amq-router.amq-router.svc.cluster.local"
```
2. Configure the linuxptp and phc2sys for the PTP clock type and interface. For example, add the following stanza into .sourceFiles:
```
- fileName: PtpConfigSlave.yaml 1
  policyName: "config-policy"
  metadata:
    name: "du-ptp-slave"
  spec:
    profile:
    - name: "slave"
      interface: "ens5f1" 2
      ptp4lOpts: "-2 -s --summary_interval -4" 3
      phc2sysOpts: "-a -r -m -n 24 -N 8 -R 16" 4
    ptpClockThreshold: 5
      holdOverTimeout: 30 #secs
      maxOffsetThreshold: 100  #nano secs
      minOffsetThreshold: -100 #nano secs
```
  1
  Can be PtpConfigMaster.yaml or PtpConfigSlave.yaml depending on your requirements. For configurations based on group-du-sno-ranGen.yaml or group-du-3node-ranGen.yaml, use PtpConfigSlave.yaml.
  2
  Device specific interface name.
  3
  You must append the --summary_interval -4 value to ptp4lOpts in .spec.sourceFiles.spec.profile to enable PTP fast events.
  4
  Required phc2sysOpts values. -m prints messages to stdout. The linuxptp-daemon DaemonSet parses the logs and generates Prometheus metrics.
  5
  Optional. If the ptpClockThreshold stanza is not present, default values are used for the ptpClockThreshold fields. The stanza shows default ptpClockThreshold values. The ptpClockThreshold values configure how long after the PTP master clock is disconnected before PTP events are triggered. holdOverTimeout is the time value in seconds before the PTP clock event state changes to FREERUN when the PTP master clock is disconnected. The maxOffsetThreshold and minOffsetThreshold settings configure offset values in nanoseconds that compare against the values for CLOCK_REALTIME (phc2sys) or master offset (ptp4l). When the ptp4l or phc2sys offset value is outside this range, the PTP clock state is set to FREERUN. When the offset value is within this range, the PTP clock state is set to LOCKED.
Apply the following PolicyGenTemplate changes to your specific site YAML files, for example, example-sno-site.yaml:
1. In .sourceFiles, add the Interconnect CR file that configures the AMQ router to the config-policy:
```
- fileName: AmqInstance.yaml
  policyName: "config-policy"
```
Merge any other required changes and files with your custom site repository.
Push the changes to your site configuration repository to deploy PTP fast events to new sites using GitOps ZTP.

Additional resources

Installing the AMQ messaging bus
For more information about container image registries, see OpenShift image registry overview.

18.10.9. Configuring bare-metal events with PolicyGenTemplate CRs

You can use the GitOps ZTP pipeline to configure bare-metal events that use HTTP or AMQP transport.

Note

18.10.9.1. Configuring bare-metal events that use HTTP transport

You can configure bare-metal events that use HTTP transport on managed clusters that you deploy with the GitOps Zero Touch Provisioning (ZTP) pipeline.

Prerequisites

You have installed the OpenShift CLI (oc).
You have logged in as a user with cluster-admin privileges.
You have created a Git repository where you manage your custom site configuration data.

Procedure

Configure the Bare Metal Event Relay Operator by adding the following YAML to spec.sourceFiles in the common-ranGen.yaml file:

# Bare Metal Event Relay operator
- fileName: BareMetalEventRelaySubscriptionNS.yaml
  policyName: "subscriptions-policy"
- fileName: BareMetalEventRelaySubscriptionOperGroup.yaml
  policyName: "subscriptions-policy"
- fileName: BareMetalEventRelaySubscription.yaml
  policyName: "subscriptions-policy"

Add the HardwareEvent CR to spec.sourceFiles in your specific group configuration file, for example, in the group-du-sno-ranGen.yaml file:
```
- fileName: HardwareEvent.yaml 1
  policyName: "config-policy"
  spec:
    nodeSelector: {}
    transportHost: "http://hw-event-publisher-service.openshift-bare-metal-events.svc.cluster.local:9043"
    logLevel: "info"
```
1
Each baseboard management controller (BMC) requires a single HardwareEvent CR only.
Note
In OpenShift Container Platform 4.13 or later, you do not need to set the transportHost field in the HardwareEvent custom resource (CR) when you use HTTP transport with bare-metal events.
Merge any other required changes and files with your custom site repository.
Push the changes to your site configuration repository to deploy bare-metal events to new sites with GitOps ZTP.

Create the Redfish Secret by running the following command:

$ oc -n openshift-bare-metal-events create secret generic redfish-basic-auth \
--from-literal=username=<bmc_username> --from-literal=password=<bmc_password> \
--from-literal=hostaddr="<bmc_host_ip_addr>"

Additional resources

Installing the Bare Metal Event Relay using the CLI
Creating the bare-metal event and Secret CRs

18.10.9.2. Configuring bare-metal events that use AMQP transport

You can configure bare-metal events that use AMQP transport on managed clusters that you deploy with the GitOps Zero Touch Provisioning (ZTP) pipeline.

Note

Prerequisites

You have installed the OpenShift CLI (oc).
You have logged in as a user with cluster-admin privileges.
You have created a Git repository where you manage your custom site configuration data.

Procedure

To configure the AMQ Interconnect Operator and the Bare Metal Event Relay Operator, add the following YAML to spec.sourceFiles in the common-ranGen.yaml file:

# AMQ interconnect operator for fast events
- fileName: AmqSubscriptionNS.yaml
  policyName: "subscriptions-policy"
- fileName: AmqSubscriptionOperGroup.yaml
  policyName: "subscriptions-policy"
- fileName: AmqSubscription.yaml
  policyName: "subscriptions-policy"
# Bare Metal Event Rely operator
- fileName: BareMetalEventRelaySubscriptionNS.yaml
  policyName: "subscriptions-policy"
- fileName: BareMetalEventRelaySubscriptionOperGroup.yaml
  policyName: "subscriptions-policy"
- fileName: BareMetalEventRelaySubscription.yaml
  policyName: "subscriptions-policy"

Add the Interconnect CR to .spec.sourceFiles in the site configuration file, for example, the example-sno-site.yaml file:
```
- fileName: AmqInstance.yaml
  policyName: "config-policy"
```
Add the HardwareEvent CR to spec.sourceFiles in your specific group configuration file, for example, in the group-du-sno-ranGen.yaml file:
```
- fileName: HardwareEvent.yaml
  policyName: "config-policy"
  spec:
    nodeSelector: {}
    transportHost: "amqp://<amq_interconnect_name>.<amq_interconnect_namespace>.svc.cluster.local" 1
    logLevel: "info"
```
1
The transportHost URL is composed of the existing AMQ Interconnect CR name and namespace. For example, in transportHost: "amqp://amq-router.amq-router.svc.cluster.local", the AMQ Interconnect name and namespace are both set to amq-router.
Note
Each baseboard management controller (BMC) requires a single HardwareEvent resource only.
Commit the PolicyGenTemplate change in Git, and then push the changes to your site configuration repository to deploy bare-metal events monitoring to new sites using GitOps ZTP.

Create the Redfish Secret by running the following command:

$ oc -n openshift-bare-metal-events create secret generic redfish-basic-auth \
--from-literal=username=<bmc_username> --from-literal=password=<bmc_password> \
--from-literal=hostaddr="<bmc_host_ip_addr>"

18.10.10. Configuring the Image Registry Operator for local caching of images

OpenShift Container Platform manages image caching using a local registry. In edge computing use cases, clusters are often subject to bandwidth restrictions when communicating with centralized image registries, which might result in long image download times.

Long download times are unavoidable during initial deployment. Over time, there is a risk that CRI-O will erase the /var/lib/containers/storage directory in the case of an unexpected shutdown. To address long image download times, you can create a local image registry on remote managed clusters using GitOps Zero Touch Provisioning (ZTP). This is useful in Edge computing scenarios where clusters are deployed at the far edge of the network.

Before you can set up the local image registry with GitOps ZTP, you need to configure disk partitioning in the SiteConfig CR that you use to install the remote managed cluster. After installation, you configure the local image registry using a PolicyGenTemplate CR. Then, the GitOps ZTP pipeline creates Persistent Volume (PV) and Persistent Volume Claim (PVC) CRs and patches the imageregistry configuration.

Note

The local image registry can only be used for user application images and cannot be used for the OpenShift Container Platform or Operator Lifecycle Manager operator images.

Additional resources

OpenShift Container Platform registry overview.

18.10.10.1. Configuring disk partitioning with SiteConfig

Configure disk partitioning for a managed cluster using a SiteConfig CR and GitOps Zero Touch Provisioning (ZTP). The disk partition details in the SiteConfig CR must match the underlying disk.

Important

You must complete this procedure at installation time.

Prerequisites

Install Butane.

Procedure

Create the storage.bu file by using the following example YAML file:

variant: fcos
version: 1.3.0
storage:
  disks:
  - device: /dev/disk/by-path/pci-0000:01:00.0-scsi-0:2:0:0 1
    wipe_table: false
    partitions:
    - label: var-lib-containers
      start_mib: <start_of_partition> 2
      size_mib: <partition_size> 3
  filesystems:
    - path: /var/lib/containers
      device: /dev/disk/by-partlabel/var-lib-containers
      format: xfs
      wipe_filesystem: true
      with_mount_unit: true
      mount_options:
        - defaults
        - prjquota

1: Specify the root disk.
2: Specify the start of the partition in MiB. If the value is too small, the installation fails.
3: Specify the size of the partition. If the value is too small, the deployments fails.

Convert the storage.bu to an Ignition file by running the following command:

$ butane storage.bu

Example output

{"ignition":{"version":"3.2.0"},"storage":{"disks":[{"device":"/dev/disk/by-path/pci-0000:01:00.0-scsi-0:2:0:0","partitions":[{"label":"var-lib-containers","sizeMiB":0,"startMiB":250000}],"wipeTable":false}],"filesystems":[{"device":"/dev/disk/by-partlabel/var-lib-containers","format":"xfs","mountOptions":["defaults","prjquota"],"path":"/var/lib/containers","wipeFilesystem":true}]},"systemd":{"units":[{"contents":"# # Generated by Butane\n[Unit]\nRequires=systemd-fsck@dev-disk-by\\x2dpartlabel-var\\x2dlib\\x2dcontainers.service\nAfter=systemd-fsck@dev-disk-by\\x2dpartlabel-var\\x2dlib\\x2dcontainers.service\n\n[Mount]\nWhere=/var/lib/containers\nWhat=/dev/disk/by-partlabel/var-lib-containers\nType=xfs\nOptions=defaults,prjquota\n\n[Install]\nRequiredBy=local-fs.target","enabled":true,"name":"var-lib-containers.mount"}]}}

Use a tool such as JSON Pretty Print to convert the output into JSON format.

Copy the output into the .spec.clusters.nodes.ignitionConfigOverride field in the SiteConfig CR.

Example

[...]
spec:
  clusters:
    - nodes:
        - ignitionConfigOverride: |
          {
            "ignition": {
              "version": "3.2.0"
            },
            "storage": {
              "disks": [
                {
                  "device": "/dev/disk/by-path/pci-0000:01:00.0-scsi-0:2:0:0",
                  "partitions": [
                    {
                      "label": "var-lib-containers",
                      "sizeMiB": 0,
                      "startMiB": 250000
                    }
                  ],
                  "wipeTable": false
                }
              ],
              "filesystems": [
                {
                  "device": "/dev/disk/by-partlabel/var-lib-containers",
                  "format": "xfs",
                  "mountOptions": [
                    "defaults",
                    "prjquota"
                  ],
                  "path": "/var/lib/containers",
                  "wipeFilesystem": true
                }
              ]
            },
            "systemd": {
              "units": [
                {
                  "contents": "# # Generated by Butane\n[Unit]\nRequires=systemd-fsck@dev-disk-by\\x2dpartlabel-var\\x2dlib\\x2dcontainers.service\nAfter=systemd-fsck@dev-disk-by\\x2dpartlabel-var\\x2dlib\\x2dcontainers.service\n\n[Mount]\nWhere=/var/lib/containers\nWhat=/dev/disk/by-partlabel/var-lib-containers\nType=xfs\nOptions=defaults,prjquota\n\n[Install]\nRequiredBy=local-fs.target",
                  "enabled": true,
                  "name": "var-lib-containers.mount"
                }
              ]
            }
          }
[...]

Note

If the .spec.clusters.nodes.ignitionConfigOverride field does not exist, create it.

Verification

During or after installation, verify on the hub cluster that the BareMetalHost object shows the annotation by running the following command:

$ oc get bmh -n my-sno-ns my-sno -ojson | jq '.metadata.annotations["bmac.agent-install.openshift.io/ignition-config-overrides"]

Example output

"{\"ignition\":{\"version\":\"3.2.0\"},\"storage\":{\"disks\":[{\"device\":\"/dev/disk/by-id/wwn-0x6b07b250ebb9d0002a33509f24af1f62\",\"partitions\":[{\"label\":\"var-lib-containers\",\"sizeMiB\":0,\"startMiB\":250000}],\"wipeTable\":false}],\"filesystems\":[{\"device\":\"/dev/disk/by-partlabel/var-lib-containers\",\"format\":\"xfs\",\"mountOptions\":[\"defaults\",\"prjquota\"],\"path\":\"/var/lib/containers\",\"wipeFilesystem\":true}]},\"systemd\":{\"units\":[{\"contents\":\"# Generated by Butane\\n[Unit]\\nRequires=systemd-fsck@dev-disk-by\\\\x2dpartlabel-var\\\\x2dlib\\\\x2dcontainers.service\\nAfter=systemd-fsck@dev-disk-by\\\\x2dpartlabel-var\\\\x2dlib\\\\x2dcontainers.service\\n\\n[Mount]\\nWhere=/var/lib/containers\\nWhat=/dev/disk/by-partlabel/var-lib-containers\\nType=xfs\\nOptions=defaults,prjquota\\n\\n[Install]\\nRequiredBy=local-fs.target\",\"enabled\":true,\"name\":\"var-lib-containers.mount\"}]}}"

After installation, check the single-node OpenShift disk status.

Enter into a debug session on the single-node OpenShift node by running the following command.

This step instantiates a debug pod called <node_name>-debug:

$ oc debug node/my-sno-node

Set /host as the root directory within the debug shell by running the following command.
The debug pod mounts the host’s root file system in /host within the pod. By changing the root directory to /host, you can run binaries contained in the host’s executable paths:
```
# chroot /host
```

List information about all available block devices by running the following command:

# lsblk

Example output

NAME   MAJ:MIN RM   SIZE RO TYPE MOUNTPOINTS
sda      8:0    0 446.6G  0 disk
├─sda1   8:1    0     1M  0 part
├─sda2   8:2    0   127M  0 part
├─sda3   8:3    0   384M  0 part /boot
├─sda4   8:4    0 243.6G  0 part /var
│                                /sysroot/ostree/deploy/rhcos/var
│                                /usr
│                                /etc
│                                /
│                                /sysroot
└─sda5   8:5    0 202.5G  0 part /var/lib/containers

Display information about the file system disk space usage by running the following command:

# df -h

Example output

Filesystem      Size  Used Avail Use% Mounted on
devtmpfs        4.0M     0  4.0M   0% /dev
tmpfs           126G   84K  126G   1% /dev/shm
tmpfs            51G   93M   51G   1% /run
/dev/sda4       244G  5.2G  239G   3% /sysroot
tmpfs           126G  4.0K  126G   1% /tmp
/dev/sda5       203G  119G   85G  59% /var/lib/containers
/dev/sda3       350M  110M  218M  34% /boot
tmpfs            26G     0   26G   0% /run/user/1000

18.10.10.2. Configuring the image registry using PolicyGenTemplate CRs

Use PolicyGenTemplate (PGT) CRs to apply the CRs required to configure the image registry and patch the imageregistry configuration.

Prerequisites

You have configured a disk partition in the managed cluster.
You have installed the OpenShift CLI (oc).
You have logged in to the hub cluster as a user with cluster-admin privileges.
You have created a Git repository where you manage your custom site configuration data for use with GitOps Zero Touch Provisioning (ZTP).

Procedure

Configure the storage class, persistent volume claim, persistent volume, and image registry configuration in the appropriate PolicyGenTemplate CR. For example, to configure an individual site, add the following YAML to the file example-sno-site.yaml:

sourceFiles:
  # storage class
  - fileName: StorageClass.yaml
    policyName: "sc-for-image-registry"
    metadata:
      name: image-registry-sc
      annotations:
        ran.openshift.io/ztp-deploy-wave: "100" 1
  # persistent volume claim
  - fileName: StoragePVC.yaml
    policyName: "pvc-for-image-registry"
    metadata:
      name: image-registry-pvc
      namespace: openshift-image-registry
      annotations:
        ran.openshift.io/ztp-deploy-wave: "100"
    spec:
      accessModes:
        - ReadWriteMany
      resources:
        requests:
          storage: 100Gi
      storageClassName: image-registry-sc
      volumeMode: Filesystem
  # persistent volume
  - fileName: ImageRegistryPV.yaml 2
    policyName: "pv-for-image-registry"
    metadata:
      annotations:
        ran.openshift.io/ztp-deploy-wave: "100"
  - fileName: ImageRegistryConfig.yaml
    policyName: "config-for-image-registry"
    complianceType: musthave
    metadata:
      annotations:
        ran.openshift.io/ztp-deploy-wave: "100"
    spec:
      storage:
        pvc:
          claim: "image-registry-pvc"

1: Set the appropriate value for ztp-deploy-wave depending on whether you are configuring image registries at the site, common, or group level. ztp-deploy-wave: "100" is suitable for development or testing because it allows you to group the referenced source files together.
2: In ImageRegistryPV.yaml, ensure that the spec.local.path field is set to /var/imageregistry to match the value set for the mount_point field in the SiteConfig CR.

Important

Do not set complianceType: mustonlyhave for the - fileName: ImageRegistryConfig.yaml configuration. This can cause the registry pod deployment to fail.

Commit the PolicyGenTemplate change in Git, and then push to the Git repository being monitored by the GitOps ZTP ArgoCD application.

Verification

Use the following steps to troubleshoot errors with the local image registry on the managed clusters:

Verify successful login to the registry while logged in to the managed cluster. Run the following commands:

Export the managed cluster name:
```
$ cluster=<managed_cluster_name>
```

Get the managed cluster kubeconfig details:

$ oc get secret -n $cluster $cluster-admin-password -o jsonpath='{.data.password}' | base64 -d > kubeadmin-password-$cluster

Download and export the cluster kubeconfig:

$ oc get secret -n $cluster $cluster-admin-kubeconfig -o jsonpath='{.data.kubeconfig}' | base64 -d > kubeconfig-$cluster && export KUBECONFIG=./kubeconfig-$cluster

Verify access to the image registry from the managed cluster. See "Accessing the registry".

Check that the Config CRD in the imageregistry.operator.openshift.io group instance is not reporting errors. Run the following command while logged in to the managed cluster:

$ oc get image.config.openshift.io cluster -o yaml

Example output

apiVersion: config.openshift.io/v1
kind: Image
metadata:
  annotations:
    include.release.openshift.io/ibm-cloud-managed: "true"
    include.release.openshift.io/self-managed-high-availability: "true"
    include.release.openshift.io/single-node-developer: "true"
    release.openshift.io/create-only: "true"
  creationTimestamp: "2021-10-08T19:02:39Z"
  generation: 5
  name: cluster
  resourceVersion: "688678648"
  uid: 0406521b-39c0-4cda-ba75-873697da75a4
spec:
  additionalTrustedCA:
    name: acm-ice

Check that the PersistentVolumeClaim on the managed cluster is populated with data. Run the following command while logged in to the managed cluster:
```
$ oc get pv image-registry-sc
```

Check that the registry* pod is running and is located under the openshift-image-registry namespace.

$ oc get pods -n openshift-image-registry | grep registry*

Example output

cluster-image-registry-operator-68f5c9c589-42cfg   1/1     Running     0          8d
image-registry-5f8987879-6nx6h                     1/1     Running     0          8d

Check that the disk partition on the managed cluster is correct:

Open a debug shell to the managed cluster:
```
$ oc debug node/sno-1.example.com
```

Run lsblk to check the host disk partitions:

sh-4.4# lsblk
NAME   MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
sda      8:0    0 446.6G  0 disk
  |-sda1   8:1    0     1M  0 part
  |-sda2   8:2    0   127M  0 part
  |-sda3   8:3    0   384M  0 part /boot
  |-sda4   8:4    0 336.3G  0 part /sysroot
  `-sda5   8:5    0 100.1G  0 part /var/imageregistry 1
sdb      8:16   0 446.6G  0 disk
sr0     11:0    1   104M  0 rom

1: /var/imageregistry indicates that the disk is correctly partitioned.

Additional resources

Accessing the registry

18.10.11. Using hub templates in PolicyGenTemplate CRs

Topology Aware Lifecycle Manager supports partial Red Hat Advanced Cluster Management (RHACM) hub cluster template functions in configuration policies used with GitOps Zero Touch Provisioning (ZTP).

Hub-side cluster templates allow you to define configuration policies that can be dynamically customized to the target clusters. This reduces the need to create separate policies for many clusters with similiar configurations but with different values.

Important

Policy templates are restricted to the same namespace as the namespace where the policy is defined. This means that you must create the objects referenced in the hub template in the same namespace where the policy is created.

The following supported hub template functions are available for use in GitOps ZTP with TALM:

fromConfigmap returns the value of the provided data key in the named ConfigMap resource.
Note
There is a 1 MiB size limit for ConfigMap CRs. The effective size for ConfigMap CRs is further limited by the last-applied-configuration annotation. To avoid the last-applied-configuration limitation, add the following annotation to the template ConfigMap:
```
argocd.argoproj.io/sync-options: Replace=true
```
base64enc returns the base64-encoded value of the input string
base64dec returns the decoded value of the base64-encoded input string
indent returns the input string with added indent spaces
autoindent returns the input string with added indent spaces based on the spacing used in the parent template
toInt casts and returns the integer value of the input value
toBool converts the input string into a boolean value, and returns the boolean

Various Open source community functions are also available for use with GitOps ZTP.

Additional resources

RHACM support for hub cluster templates in configuration policies

18.10.11.1. Example hub templates

The following code examples are valid hub templates. Each of these templates return values from the ConfigMap CR with the name test-config in the default namespace.

Returns the value with the key common-key:

{{hub fromConfigMap "default" "test-config" "common-key" hub}}

Returns a string by using the concatenated value of the .ManagedClusterName field and the string -name:
```
{{hub fromConfigMap "default" "test-config" (printf "%s-name" .ManagedClusterName) hub}}
```
Casts and returns a boolean value from the concatenated value of the .ManagedClusterName field and the string -name:
```
{{hub fromConfigMap "default" "test-config" (printf "%s-name" .ManagedClusterName) | toBool hub}}
```
Casts and returns an integer value from the concatenated value of the .ManagedClusterName field and the string -name:
```
{{hub (printf "%s-name" .ManagedClusterName) | fromConfigMap "default" "test-config" | toInt hub}}
```

18.10.11.2. Specifying host NICs in site PolicyGenTemplate CRs with hub cluster templates

You can manage host NICs in a single ConfigMap CR and use hub cluster templates to populate the custom NIC values in the generated polices that get applied to the cluster hosts. Using hub cluster templates in site PolicyGenTemplate (PGT) CRs means that you do not need to create multiple single site PGT CRs for each site.

The following example shows you how to use a single ConfigMap CR to manage cluster host NICs and apply them to the cluster as polices by using a single PolicyGenTemplate site CR.

Note

When you use the fromConfigmap function, the printf variable is only available for the template resource data key fields. You cannot use it with name and namespace fields.

Prerequisites

You have installed the OpenShift CLI (oc).
You have logged in to the hub cluster as a user with cluster-admin privileges.
You have created a Git repository where you manage your custom site configuration data. The repository must be accessible from the hub cluster and be defined as a source repository for the GitOps ZTP ArgoCD application.

Procedure

Create a ConfigMap resource that describes the NICs for a group of hosts. For example:

apiVersion: v1
kind: ConfigMap
metadata:
  name: sriovdata
  namespace: ztp-site
  annotations:
    argocd.argoproj.io/sync-options: Replace=true 1
data:
  example-sno-du_fh-numVfs: "8"
  example-sno-du_fh-pf: ens1f0
  example-sno-du_fh-priority: "10"
  example-sno-du_fh-vlan: "140"
  example-sno-du_mh-numVfs: "8"
  example-sno-du_mh-pf: ens3f0
  example-sno-du_mh-priority: "10"
  example-sno-du_mh-vlan: "150"

1: The argocd.argoproj.io/sync-options annotation is required only if the ConfigMap is larger than 1 MiB in size.

Note

The ConfigMap must be in the same namespace with the policy that has the hub template substitution.

Commit the ConfigMap CR in Git, and then push to the Git repository being monitored by the Argo CD application.

Create a site PGT CR that uses templates to pull the required data from the ConfigMap object. For example:

apiVersion: ran.openshift.io/v1
kind: PolicyGenTemplate
metadata:
  name: "site"
  namespace: "ztp-site"
spec:
  remediationAction: inform
  bindingRules:
    group-du-sno: ""
  mcp: "master"
  sourceFiles:
    - fileName: SriovNetwork.yaml
      policyName: "config-policy"
      metadata:
        name: "sriov-nw-du-fh"
      spec:
        resourceName: du_fh
        vlan: '{{hub fromConfigMap "ztp-site" "sriovdata" (printf "%s-du_fh-vlan" .ManagedClusterName) | toInt hub}}'
    - fileName: SriovNetworkNodePolicy.yaml
      policyName: "config-policy"
      metadata:
        name: "sriov-nnp-du-fh"
      spec:
        deviceType: netdevice
        isRdma: true
        nicSelector:
          pfNames:
          - '{{hub fromConfigMap "ztp-site" "sriovdata" (printf "%s-du_fh-pf" .ManagedClusterName) | autoindent hub}}'
        numVfs: '{{hub fromConfigMap "ztp-site" "sriovdata" (printf "%s-du_fh-numVfs" .ManagedClusterName) | toInt hub}}'
        priority: '{{hub fromConfigMap "ztp-site" "sriovdata" (printf "%s-du_fh-priority" .ManagedClusterName) | toInt hub}}'
        resourceName: du_fh
    - fileName: SriovNetwork.yaml
      policyName: "config-policy"
      metadata:
        name: "sriov-nw-du-mh"
      spec:
        resourceName: du_mh
        vlan: '{{hub fromConfigMap "ztp-site" "sriovdata" (printf "%s-du_mh-vlan" .ManagedClusterName) | toInt hub}}'
    - fileName: SriovNetworkNodePolicy.yaml
      policyName: "config-policy"
      metadata:
        name: "sriov-nnp-du-mh"
      spec:
        deviceType: vfio-pci
        isRdma: false
        nicSelector:
          pfNames:
          - '{{hub fromConfigMap "ztp-site" "sriovdata" (printf "%s-du_mh-pf" .ManagedClusterName)  hub}}'
        numVfs: '{{hub fromConfigMap "ztp-site" "sriovdata" (printf "%s-du_mh-numVfs" .ManagedClusterName) | toInt hub}}'
        priority: '{{hub fromConfigMap "ztp-site" "sriovdata" (printf "%s-du_mh-priority" .ManagedClusterName) | toInt hub}}'
        resourceName: du_mh

Commit the site PolicyGenTemplate CR in Git and push to the Git repository that is monitored by the ArgoCD application.
Note
Subsequent changes to the referenced ConfigMap CR are not automatically synced to the applied policies. You need to manually sync the new ConfigMap changes to update existing PolicyGenTemplate CRs. See "Syncing new ConfigMap changes to existing PolicyGenTemplate CRs".

18.10.11.3. Specifying VLAN IDs in group PolicyGenTemplate CRs with hub cluster templates

You can manage VLAN IDs for managed clusters in a single ConfigMap CR and use hub cluster templates to populate the VLAN IDs in the generated polices that get applied to the clusters.

The following example shows how you how manage VLAN IDs in single ConfigMap CR and apply them in individual cluster polices by using a single PolicyGenTemplate group CR.

Note

When using the fromConfigmap function, the printf variable is only available for the template resource data key fields. You cannot use it with name and namespace fields.

Prerequisites

You have installed the OpenShift CLI (oc).
You have logged in to the hub cluster as a user with cluster-admin privileges.
You have created a Git repository where you manage your custom site configuration data. The repository must be accessible from the hub cluster and be defined as a source repository for the Argo CD application.

Procedure

Create a ConfigMap CR that describes the VLAN IDs for a group of cluster hosts. For example:
```
apiVersion: v1
kind: ConfigMap
metadata:
  name: site-data
  namespace: ztp-group
  annotations:
    argocd.argoproj.io/sync-options: Replace=true 1
data:
  site-1-vlan: "101"
  site-2-vlan: "234"
```
1
The argocd.argoproj.io/sync-options annotation is required only if the ConfigMap is larger than 1 MiB in size.
Note
The ConfigMap must be in the same namespace with the policy that has the hub template substitution.
Commit the ConfigMap CR in Git, and then push to the Git repository being monitored by the Argo CD application.

Create a group PGT CR that uses a hub template to pull the required VLAN IDs from the ConfigMap object. For example, add the following YAML snippet to the group PGT CR:

- fileName: SriovNetwork.yaml
    policyName: "config-policy"
    metadata:
      name: "sriov-nw-du-mh"
      annotations:
        ran.openshift.io/ztp-deploy-wave: "10"
    spec:
      resourceName: du_mh
      vlan: '{{hub fromConfigMap "" "site-data" (printf "%s-vlan" .ManagedClusterName) | toInt hub}}'

Commit the group PolicyGenTemplate CR in Git, and then push to the Git repository being monitored by the Argo CD application.
Note
Subsequent changes to the referenced ConfigMap CR are not automatically synced to the applied policies. You need to manually sync the new ConfigMap changes to update existing PolicyGenTemplate CRs. See "Syncing new ConfigMap changes to existing PolicyGenTemplate CRs".

18.10.11.4. Syncing new ConfigMap changes to existing PolicyGenTemplate CRs

Prerequisites

You have installed the OpenShift CLI (oc).
You have logged in to the hub cluster as a user with cluster-admin privileges.
You have created a PolicyGenTemplate CR that pulls information from a ConfigMap CR using hub cluster templates.

Procedure

Update the contents of your ConfigMap CR, and apply the changes in the hub cluster.
To sync the contents of the updated ConfigMap CR to the deployed policy, do either of the following:
1. Option 1: Delete the existing policy. ArgoCD uses the PolicyGenTemplate CR to immediately recreate the deleted policy. For example, run the following command:
```
$ oc delete policy <policy_name> -n <policy_namespace>
```
2. Option 2: Apply a special annotation policy.open-cluster-management.io/trigger-update to the policy with a different value every time when you update the ConfigMap. For example:
```
$ oc annotate policy <policy_name> -n <policy_namespace> policy.open-cluster-management.io/trigger-update="1"
```
  Note
  You must apply the updated policy for the changes to take effect. For more information, see Special annotation for reprocessing.

Optional: If it exists, delete the ClusterGroupUpdate CR that contains the policy. For example:

$ oc delete clustergroupupgrade <cgu_name> -n <cgu_namespace>

Create a new ClusterGroupUpdate CR that includes the policy to apply with the updated ConfigMap changes. For example, add the following YAML to the file cgr-example.yaml:

apiVersion: ran.openshift.io/v1alpha1
kind: ClusterGroupUpgrade
metadata:
  name: <cgr_name>
  namespace: <policy_namespace>
spec:
  managedPolicies:
    - <managed_policy>
  enable: true
  clusters:
  - <managed_cluster_1>
  - <managed_cluster_2>
  remediationStrategy:
    maxConcurrency: 2
    timeout: 240

Apply the updated policy:
```
$ oc apply -f cgr-example.yaml
```

18.11. Updating managed clusters with the Topology Aware Lifecycle Manager

You can use the Topology Aware Lifecycle Manager (TALM) to manage the software lifecycle of multiple clusters. TALM uses Red Hat Advanced Cluster Management (RHACM) policies to perform changes on the target clusters.

18.11.1. About the Topology Aware Lifecycle Manager configuration

The Topology Aware Lifecycle Manager (TALM) manages the deployment of Red Hat Advanced Cluster Management (RHACM) policies for one or more OpenShift Container Platform clusters. Using TALM in a large network of clusters allows the phased rollout of policies to the clusters in limited batches. This helps to minimize possible service disruptions when updating. With TALM, you can control the following actions:

The timing of the update
The number of RHACM-managed clusters
The subset of managed clusters to apply the policies to
The update order of the clusters
The set of policies remediated to the cluster
The order of policies remediated to the cluster
The assignment of a canary cluster

For single-node OpenShift, the Topology Aware Lifecycle Manager (TALM) offers the following features:

Create a backup of a deployment before an upgrade
Pre-caching images for clusters with limited bandwidth

TALM supports the orchestration of the OpenShift Container Platform y-stream and z-stream updates, and day-two operations on y-streams and z-streams.

18.11.2. About managed policies used with Topology Aware Lifecycle Manager

The Topology Aware Lifecycle Manager (TALM) uses RHACM policies for cluster updates.

TALM can be used to manage the rollout of any policy CR where the remediationAction field is set to inform. Supported use cases include the following:

Manual user creation of policy CRs
Automatically generated policies from the PolicyGenTemplate custom resource definition (CRD)

For policies that update an Operator subscription with manual approval, TALM provides additional functionality that approves the installation of the updated Operator.

For more information about managed policies, see Policy Overview in the RHACM documentation.

For more information about the PolicyGenTemplate CRD, see the "About the PolicyGenTemplate CRD" section in "Configuring managed clusters with policies and PolicyGenTemplate resources".

18.11.3. Installing the Topology Aware Lifecycle Manager by using the web console

You can use the OpenShift Container Platform web console to install the Topology Aware Lifecycle Manager.

Prerequisites

Install the latest version of the RHACM Operator.
Set up a hub cluster with disconnected regitry.
Log in as a user with cluster-admin privileges.

Procedure

In the OpenShift Container Platform web console, navigate to Operators → OperatorHub.
Search for the Topology Aware Lifecycle Manager from the list of available Operators, and then click Install.
Keep the default selection of Installation mode ["All namespaces on the cluster (default)"] and Installed Namespace ("openshift-operators") to ensure that the Operator is installed properly.
Click Install.

Verification

To confirm that the installation is successful:

Navigate to the Operators → Installed Operators page.
Check that the Operator is installed in the All Namespaces namespace and its status is Succeeded.

If the Operator is not installed successfully:

Navigate to the Operators → Installed Operators page and inspect the Status column for any errors or failures.
Navigate to the Workloads → Pods page and check the logs in any containers in the cluster-group-upgrades-controller-manager pod that are reporting issues.

18.11.4. Installing the Topology Aware Lifecycle Manager by using the CLI

You can use the OpenShift CLI (oc) to install the Topology Aware Lifecycle Manager (TALM).

Prerequisites

Install the OpenShift CLI (oc).
Install the latest version of the RHACM Operator.
Set up a hub cluster with disconnected registry.
Log in as a user with cluster-admin privileges.

Procedure

Create a Subscription CR:

Define the Subscription CR and save the YAML file, for example, talm-subscription.yaml:

apiVersion: operators.coreos.com/v1alpha1
kind: Subscription
metadata:
  name: openshift-topology-aware-lifecycle-manager-subscription
  namespace: openshift-operators
spec:
  channel: "stable"
  name: topology-aware-lifecycle-manager
  source: redhat-operators
  sourceNamespace: openshift-marketplace

Create the Subscription CR by running the following command:
```
$ oc create -f talm-subscription.yaml
```

Verification

Verify that the installation succeeded by inspecting the CSV resource:

$ oc get csv -n openshift-operators

Example output

NAME                                                   DISPLAY                            VERSION               REPLACES                           PHASE
topology-aware-lifecycle-manager.4.14.x   Topology Aware Lifecycle Manager   4.14.x                                      Succeeded

Verify that the TALM is up and running:

$ oc get deploy -n openshift-operators

Example output

NAMESPACE                                          NAME                                             READY   UP-TO-DATE   AVAILABLE   AGE
openshift-operators                                cluster-group-upgrades-controller-manager        1/1     1            1           14s

18.11.5. About the ClusterGroupUpgrade CR

The Topology Aware Lifecycle Manager (TALM) builds the remediation plan from the ClusterGroupUpgrade CR for a group of clusters. You can define the following specifications in a ClusterGroupUpgrade CR:

Clusters in the group
Blocking ClusterGroupUpgrade CRs
Applicable list of managed policies
Number of concurrent updates
Applicable canary updates
Actions to perform before and after the update
Update timing

You can control the start time of an update using the enable field in the ClusterGroupUpgrade CR. For example, if you have a scheduled maintenance window of four hours, you can prepare a ClusterGroupUpgrade CR with the enable field set to false.

You can set the timeout by configuring the spec.remediationStrategy.timeout setting as follows:

spec
  remediationStrategy:
          maxConcurrency: 1
          timeout: 240

You can use the batchTimeoutAction to determine what happens if an update fails for a cluster. You can specify continue to skip the failing cluster and continue to upgrade other clusters, or abort to stop policy remediation for all clusters. Once the timeout elapses, TALM removes all enforce policies to ensure that no further updates are made to clusters.

To apply the changes, you set the enabled field to true.

For more information see the "Applying update policies to managed clusters" section.

As TALM works through remediation of the policies to the specified clusters, the ClusterGroupUpgrade CR can report true or false statuses for a number of conditions.

Note

After TALM completes a cluster update, the cluster does not update again under the control of the same ClusterGroupUpgrade CR. You must create a new ClusterGroupUpgrade CR in the following cases:

When you need to update the cluster again
When the cluster changes to non-compliant with the inform policy after being updated

18.11.5.1. Selecting clusters

TALM builds a remediation plan and selects clusters based on the following fields:

The clusterLabelSelector field specifies the labels of the clusters that you want to update. This consists of a list of the standard label selectors from k8s.io/apimachinery/pkg/apis/meta/v1. Each selector in the list uses either label value pairs or label expressions. Matches from each selector are added to the final list of clusters along with the matches from the clusterSelector field and the cluster field.
The clusters field specifies a list of clusters to update.
The canaries field specifies the clusters for canary updates.
The maxConcurrency field specifies the number of clusters to update in a batch.
The actions field specifies beforeEnable actions that TALM takes as it begins the update process, and afterCompletion actions that TALM takes as it completes policy remediation for each cluster.

You can use the clusters, clusterLabelSelector, and clusterSelector fields together to create a combined list of clusters.

The remediation plan starts with the clusters listed in the canaries field. Each canary cluster forms a single-cluster batch.

Sample ClusterGroupUpgrade CR with the enabled field set to false

apiVersion: ran.openshift.io/v1alpha1
kind: ClusterGroupUpgrade
metadata:
  creationTimestamp: '2022-11-18T16:27:15Z'
  finalizers:
    - ran.openshift.io/cleanup-finalizer
  generation: 1
  name: talm-cgu
  namespace: talm-namespace
  resourceVersion: '40451823'
  uid: cca245a5-4bca-45fa-89c0-aa6af81a596c
Spec:
  actions:
    afterCompletion: 1
      addClusterLabels:
        upgrade-done: ""
      deleteClusterLabels:
        upgrade-running: ""
      deleteObjects: true
    beforeEnable: 2
      addClusterLabels:
        upgrade-running: ""
  backup: false
  clusters: 3
    - spoke1
  enable: false 4
  managedPolicies: 5
    - talm-policy
  preCaching: false
  remediationStrategy: 6
    canaries: 7
        - spoke1
    maxConcurrency: 2 8
    timeout: 240
  clusterLabelSelectors: 9
    - matchExpressions:
      - key: label1
      operator: In
      values:
        - value1a
        - value1b
  batchTimeoutAction: 10
status: 11
    computedMaxConcurrency: 2
    conditions:
      - lastTransitionTime: '2022-11-18T16:27:15Z'
        message: All selected clusters are valid
        reason: ClusterSelectionCompleted
        status: 'True'
        type: ClustersSelected 12
      - lastTransitionTime: '2022-11-18T16:27:15Z'
        message: Completed validation
        reason: ValidationCompleted
        status: 'True'
        type: Validated 13
      - lastTransitionTime: '2022-11-18T16:37:16Z'
        message: Not enabled
        reason: NotEnabled
        status: 'False'
        type: Progressing
    managedPoliciesForUpgrade:
      - name: talm-policy
        namespace: talm-namespace
    managedPoliciesNs:
      talm-policy: talm-namespace
    remediationPlan:
      - - spoke1
      - - spoke2
        - spoke3
    status:

1: Specifies the action that TALM takes when it completes policy remediation for each cluster.
2: Specifies the action that TALM takes as it begins the update process.
3: Defines the list of clusters to update.
4: The enable field is set to false.
5: Lists the user-defined set of policies to remediate.
6: Defines the specifics of the cluster updates.
7: Defines the clusters for canary updates.
8: Defines the maximum number of concurrent updates in a batch. The number of remediation batches is the number of canary clusters, plus the number of clusters, except the canary clusters, divided by the maxConcurrency value. The clusters that are already compliant with all the managed policies are excluded from the remediation plan.
9: Displays the parameters for selecting clusters.
10: Controls what happens if a batch times out. Possible values are abort or continue. If unspecified, the default is continue.
11: Displays information about the status of the updates.
12: The ClustersSelected condition shows that all selected clusters are valid.
13: The Validated condition shows that all selected clusters have been validated.

Note

Any failures during the update of a canary cluster stops the update process.

When the remediation plan is successfully created, you can you set the enable field to true and TALM starts to update the non-compliant clusters with the specified managed policies.

Note

You can only make changes to the spec fields if the enable field of the ClusterGroupUpgrade CR is set to false.

18.11.5.2. Validating

TALM checks that all specified managed policies are available and correct, and uses the Validated condition to report the status and reasons as follows:

true
Validation is completed.
false
Policies are missing or invalid, or an invalid platform image has been specified.

18.11.5.3. Pre-caching

Clusters might have limited bandwidth to access the container image registry, which can cause a timeout before the updates are completed. On single-node OpenShift clusters, you can use pre-caching to avoid this. The container image pre-caching starts when you create a ClusterGroupUpgrade CR with the preCaching field set to true. TALM compares the available disk space with the estimated OpenShift Container Platform image size to ensure that there is enough space. If a cluster has insufficient space, TALM cancels pre-caching for that cluster and does not remediate policies on it.

TALM uses the PrecacheSpecValid condition to report status information as follows:

true
The pre-caching spec is valid and consistent.
false
The pre-caching spec is incomplete.

TALM uses the PrecachingSucceeded condition to report status information as follows:

true
TALM has concluded the pre-caching process. If pre-caching fails for any cluster, the update fails for that cluster but proceeds for all other clusters. A message informs you if pre-caching has failed for any clusters.
false
Pre-caching is still in progress for one or more clusters or has failed for all clusters.

For more information see the "Using the container image pre-cache feature" section.

18.11.5.4. Creating a backup

For single-node OpenShift, TALM can create a backup of a deployment before an update. If the update fails, you can recover the previous version and restore a cluster to a working state without requiring a reprovision of applications. To use the backup feature you first create a ClusterGroupUpgrade CR with the backup field set to true. To ensure that the contents of the backup are up to date, the backup is not taken until you set the enable field in the ClusterGroupUpgrade CR to true.

TALM uses the BackupSucceeded condition to report the status and reasons as follows:

true
Backup is completed for all clusters or the backup run has completed but failed for one or more clusters. If backup fails for any cluster, the update fails for that cluster but proceeds for all other clusters.
false
Backup is still in progress for one or more clusters or has failed for all clusters.

For more information, see the "Creating a backup of cluster resources before upgrade" section.

18.11.5.5. Updating clusters

TALM enforces the policies following the remediation plan. Enforcing the policies for subsequent batches starts immediately after all the clusters of the current batch are compliant with all the managed policies. If the batch times out, TALM moves on to the next batch. The timeout value of a batch is the spec.timeout field divided by the number of batches in the remediation plan.

TALM uses the Progressing condition to report the status and reasons as follows:

true
TALM is remediating non-compliant policies.
false
The update is not in progress. Possible reasons for this are:
- All clusters are compliant with all the managed policies.
- The update has timed out as policy remediation took too long.
- Blocking CRs are missing from the system or have not yet completed.
- The ClusterGroupUpgrade CR is not enabled.
- Backup is still in progress.

Note

The managed policies apply in the order that they are listed in the managedPolicies field in the ClusterGroupUpgrade CR. One managed policy is applied to the specified clusters at a time. When a cluster complies with the current policy, the next managed policy is applied to it.

Sample ClusterGroupUpgrade CR in the Progressing state

apiVersion: ran.openshift.io/v1alpha1
kind: ClusterGroupUpgrade
metadata:
  creationTimestamp: '2022-11-18T16:27:15Z'
  finalizers:
    - ran.openshift.io/cleanup-finalizer
  generation: 1
  name: talm-cgu
  namespace: talm-namespace
  resourceVersion: '40451823'
  uid: cca245a5-4bca-45fa-89c0-aa6af81a596c
Spec:
  actions:
    afterCompletion:
      deleteObjects: true
    beforeEnable: {}
  backup: false
  clusters:
    - spoke1
  enable: true
  managedPolicies:
    - talm-policy
  preCaching: true
  remediationStrategy:
    canaries:
        - spoke1
    maxConcurrency: 2
    timeout: 240
  clusterLabelSelectors:
    - matchExpressions:
      - key: label1
      operator: In
      values:
        - value1a
        - value1b
  batchTimeoutAction:
status:
    clusters:
      - name: spoke1
        state: complete
    computedMaxConcurrency: 2
    conditions:
      - lastTransitionTime: '2022-11-18T16:27:15Z'
        message: All selected clusters are valid
        reason: ClusterSelectionCompleted
        status: 'True'
        type: ClustersSelected
      - lastTransitionTime: '2022-11-18T16:27:15Z'
        message: Completed validation
        reason: ValidationCompleted
        status: 'True'
        type: Validated
      - lastTransitionTime: '2022-11-18T16:37:16Z'
        message: Remediating non-compliant policies
        reason: InProgress
        status: 'True'
        type: Progressing 1
    managedPoliciesForUpgrade:
      - name: talm-policy
        namespace: talm-namespace
    managedPoliciesNs:
      talm-policy: talm-namespace
    remediationPlan:
      - - spoke1
      - - spoke2
        - spoke3
    status:
      currentBatch: 2
      currentBatchRemediationProgress:
        spoke2:
          state: Completed
        spoke3:
          policyIndex: 0
          state: InProgress
      currentBatchStartedAt: '2022-11-18T16:27:16Z'
      startedAt: '2022-11-18T16:27:15Z'

1: The Progressing fields show that TALM is in the process of remediating policies.

18.11.5.6. Update status

TALM uses the Succeeded condition to report the status and reasons as follows:

true
All clusters are compliant with the specified managed policies.
false
Policy remediation failed as there were no clusters available for remediation, or because policy remediation took too long for one of the following reasons:
- The current batch contains canary updates and the cluster in the batch does not comply with all the managed policies within the batch timeout.
- Clusters did not comply with the managed policies within the timeout value specified in the remediationStrategy field.

Sample ClusterGroupUpgrade CR in the Succeeded state

    apiVersion: ran.openshift.io/v1alpha1
    kind: ClusterGroupUpgrade
    metadata:
      name: cgu-upgrade-complete
      namespace: default
    spec:
      clusters:
      - spoke1
      - spoke4
      enable: true
      managedPolicies:
      - policy1-common-cluster-version-policy
      - policy2-common-pao-sub-policy
      remediationStrategy:
        maxConcurrency: 1
        timeout: 240
    status: 1
      clusters:
        - name: spoke1
          state: complete
        - name: spoke4
          state: complete
      conditions:
      - message: All selected clusters are valid
        reason: ClusterSelectionCompleted
        status: "True"
        type: ClustersSelected
      - message: Completed validation
        reason: ValidationCompleted
        status: "True"
        type: Validated
      - message: All clusters are compliant with all the managed policies
        reason: Completed
        status: "False"
        type: Progressing 2
      - message: All clusters are compliant with all the managed policies
        reason: Completed
        status: "True"
        type: Succeeded 3
      managedPoliciesForUpgrade:
      - name: policy1-common-cluster-version-policy
        namespace: default
      - name: policy2-common-pao-sub-policy
        namespace: default
      remediationPlan:
      - - spoke1
      - - spoke4
      status:
        completedAt: '2022-11-18T16:27:16Z'
        startedAt: '2022-11-18T16:27:15Z'

2: In the Progressing fields, the status is false as the update has completed; clusters are compliant with all the managed policies.
3: The Succeeded fields show that the validations completed successfully.
1: The status field includes a list of clusters and their respective statuses. The status of a cluster can be complete or timedout.

Sample ClusterGroupUpgrade CR in the timedout state

apiVersion: ran.openshift.io/v1alpha1
kind: ClusterGroupUpgrade
metadata:
  creationTimestamp: '2022-11-18T16:27:15Z'
  finalizers:
    - ran.openshift.io/cleanup-finalizer
  generation: 1
  name: talm-cgu
  namespace: talm-namespace
  resourceVersion: '40451823'
  uid: cca245a5-4bca-45fa-89c0-aa6af81a596c
spec:
  actions:
    afterCompletion:
      deleteObjects: true
    beforeEnable: {}
  backup: false
  clusters:
    - spoke1
    - spoke2
  enable: true
  managedPolicies:
    - talm-policy
  preCaching: false
  remediationStrategy:
    maxConcurrency: 2
    timeout: 240
status:
  clusters:
    - name: spoke1
      state: complete
    - currentPolicy: 1
        name: talm-policy
        status: NonCompliant
      name: spoke2
      state: timedout
  computedMaxConcurrency: 2
  conditions:
    - lastTransitionTime: '2022-11-18T16:27:15Z'
      message: All selected clusters are valid
      reason: ClusterSelectionCompleted
      status: 'True'
      type: ClustersSelected
    - lastTransitionTime: '2022-11-18T16:27:15Z'
      message: Completed validation
      reason: ValidationCompleted
      status: 'True'
      type: Validated
    - lastTransitionTime: '2022-11-18T16:37:16Z'
      message: Policy remediation took too long
      reason: TimedOut
      status: 'False'
      type: Progressing
    - lastTransitionTime: '2022-11-18T16:37:16Z'
      message: Policy remediation took too long
      reason: TimedOut
      status: 'False'
      type: Succeeded 2
  managedPoliciesForUpgrade:
    - name: talm-policy
      namespace: talm-namespace
  managedPoliciesNs:
    talm-policy: talm-namespace
  remediationPlan:
    - - spoke1
      - spoke2
  status:
        startedAt: '2022-11-18T16:27:15Z'
        completedAt: '2022-11-18T20:27:15Z'

1: If a cluster’s state is timedout, the currentPolicy field shows the name of the policy and the policy status.
2: The status for succeeded is false and the message indicates that policy remediation took too long.

18.11.5.7. Blocking ClusterGroupUpgrade CRs

You can create multiple ClusterGroupUpgrade CRs and control their order of application.

For example, if you create ClusterGroupUpgrade CR C that blocks the start of ClusterGroupUpgrade CR A, then ClusterGroupUpgrade CR A cannot start until the status of ClusterGroupUpgrade CR C becomes UpgradeComplete.

One ClusterGroupUpgrade CR can have multiple blocking CRs. In this case, all the blocking CRs must complete before the upgrade for the current CR can start.

Prerequisites

Install the Topology Aware Lifecycle Manager (TALM).
Provision one or more managed clusters.
Log in as a user with cluster-admin privileges.
Create RHACM policies in the hub cluster.

Procedure

Save the content of the ClusterGroupUpgrade CRs in the cgu-a.yaml, cgu-b.yaml, and cgu-c.yaml files.

apiVersion: ran.openshift.io/v1alpha1
kind: ClusterGroupUpgrade
metadata:
  name: cgu-a
  namespace: default
spec:
  blockingCRs: 1
  - name: cgu-c
    namespace: default
  clusters:
  - spoke1
  - spoke2
  - spoke3
  enable: false
  managedPolicies:
  - policy1-common-cluster-version-policy
  - policy2-common-pao-sub-policy
  - policy3-common-ptp-sub-policy
  remediationStrategy:
    canaries:
    - spoke1
    maxConcurrency: 2
    timeout: 240
status:
  conditions:
  - message: The ClusterGroupUpgrade CR is not enabled
    reason: UpgradeNotStarted
    status: "False"
    type: Ready
  copiedPolicies:
  - cgu-a-policy1-common-cluster-version-policy
  - cgu-a-policy2-common-pao-sub-policy
  - cgu-a-policy3-common-ptp-sub-policy
  managedPoliciesForUpgrade:
  - name: policy1-common-cluster-version-policy
    namespace: default
  - name: policy2-common-pao-sub-policy
    namespace: default
  - name: policy3-common-ptp-sub-policy
    namespace: default
  placementBindings:
  - cgu-a-policy1-common-cluster-version-policy
  - cgu-a-policy2-common-pao-sub-policy
  - cgu-a-policy3-common-ptp-sub-policy
  placementRules:
  - cgu-a-policy1-common-cluster-version-policy
  - cgu-a-policy2-common-pao-sub-policy
  - cgu-a-policy3-common-ptp-sub-policy
  remediationPlan:
  - - spoke1
  - - spoke2

1: Defines the blocking CRs. The cgu-a update cannot start until cgu-c is complete.

apiVersion: ran.openshift.io/v1alpha1
kind: ClusterGroupUpgrade
metadata:
  name: cgu-b
  namespace: default
spec:
  blockingCRs: 1
  - name: cgu-a
    namespace: default
  clusters:
  - spoke4
  - spoke5
  enable: false
  managedPolicies:
  - policy1-common-cluster-version-policy
  - policy2-common-pao-sub-policy
  - policy3-common-ptp-sub-policy
  - policy4-common-sriov-sub-policy
  remediationStrategy:
    maxConcurrency: 1
    timeout: 240
status:
  conditions:
  - message: The ClusterGroupUpgrade CR is not enabled
    reason: UpgradeNotStarted
    status: "False"
    type: Ready
  copiedPolicies:
  - cgu-b-policy1-common-cluster-version-policy
  - cgu-b-policy2-common-pao-sub-policy
  - cgu-b-policy3-common-ptp-sub-policy
  - cgu-b-policy4-common-sriov-sub-policy
  managedPoliciesForUpgrade:
  - name: policy1-common-cluster-version-policy
    namespace: default
  - name: policy2-common-pao-sub-policy
    namespace: default
  - name: policy3-common-ptp-sub-policy
    namespace: default
  - name: policy4-common-sriov-sub-policy
    namespace: default
  placementBindings:
  - cgu-b-policy1-common-cluster-version-policy
  - cgu-b-policy2-common-pao-sub-policy
  - cgu-b-policy3-common-ptp-sub-policy
  - cgu-b-policy4-common-sriov-sub-policy
  placementRules:
  - cgu-b-policy1-common-cluster-version-policy
  - cgu-b-policy2-common-pao-sub-policy
  - cgu-b-policy3-common-ptp-sub-policy
  - cgu-b-policy4-common-sriov-sub-policy
  remediationPlan:
  - - spoke4
  - - spoke5
  status: {}

1: The cgu-b update cannot start until cgu-a is complete.

apiVersion: ran.openshift.io/v1alpha1
kind: ClusterGroupUpgrade
metadata:
  name: cgu-c
  namespace: default
spec: 1
  clusters:
  - spoke6
  enable: false
  managedPolicies:
  - policy1-common-cluster-version-policy
  - policy2-common-pao-sub-policy
  - policy3-common-ptp-sub-policy
  - policy4-common-sriov-sub-policy
  remediationStrategy:
    maxConcurrency: 1
    timeout: 240
status:
  conditions:
  - message: The ClusterGroupUpgrade CR is not enabled
    reason: UpgradeNotStarted
    status: "False"
    type: Ready
  copiedPolicies:
  - cgu-c-policy1-common-cluster-version-policy
  - cgu-c-policy4-common-sriov-sub-policy
  managedPoliciesCompliantBeforeUpgrade:
  - policy2-common-pao-sub-policy
  - policy3-common-ptp-sub-policy
  managedPoliciesForUpgrade:
  - name: policy1-common-cluster-version-policy
    namespace: default
  - name: policy4-common-sriov-sub-policy
    namespace: default
  placementBindings:
  - cgu-c-policy1-common-cluster-version-policy
  - cgu-c-policy4-common-sriov-sub-policy
  placementRules:
  - cgu-c-policy1-common-cluster-version-policy
  - cgu-c-policy4-common-sriov-sub-policy
  remediationPlan:
  - - spoke6
  status: {}

1: The cgu-c update does not have any blocking CRs. TALM starts the cgu-c update when the enable field is set to true.

Create the ClusterGroupUpgrade CRs by running the following command for each relevant CR:
```
$ oc apply -f <name>.yaml
```

Start the update process by running the following command for each relevant CR:

$ oc --namespace=default patch clustergroupupgrade.ran.openshift.io/<name> \
--type merge -p '{"spec":{"enable":true}}'

The following examples show ClusterGroupUpgrade CRs where the enable field is set to true:

Example for cgu-a with blocking CRs

apiVersion: ran.openshift.io/v1alpha1
kind: ClusterGroupUpgrade
metadata:
  name: cgu-a
  namespace: default
spec:
  blockingCRs:
  - name: cgu-c
    namespace: default
  clusters:
  - spoke1
  - spoke2
  - spoke3
  enable: true
  managedPolicies:
  - policy1-common-cluster-version-policy
  - policy2-common-pao-sub-policy
  - policy3-common-ptp-sub-policy
  remediationStrategy:
    canaries:
    - spoke1
    maxConcurrency: 2
    timeout: 240
status:
  conditions:
  - message: 'The ClusterGroupUpgrade CR is blocked by other CRs that have not yet
      completed: [cgu-c]' 1
    reason: UpgradeCannotStart
    status: "False"
    type: Ready
  copiedPolicies:
  - cgu-a-policy1-common-cluster-version-policy
  - cgu-a-policy2-common-pao-sub-policy
  - cgu-a-policy3-common-ptp-sub-policy
  managedPoliciesForUpgrade:
  - name: policy1-common-cluster-version-policy
    namespace: default
  - name: policy2-common-pao-sub-policy
    namespace: default
  - name: policy3-common-ptp-sub-policy
    namespace: default
  placementBindings:
  - cgu-a-policy1-common-cluster-version-policy
  - cgu-a-policy2-common-pao-sub-policy
  - cgu-a-policy3-common-ptp-sub-policy
  placementRules:
  - cgu-a-policy1-common-cluster-version-policy
  - cgu-a-policy2-common-pao-sub-policy
  - cgu-a-policy3-common-ptp-sub-policy
  remediationPlan:
  - - spoke1
  - - spoke2
  status: {}

1: Shows the list of blocking CRs.

Example for cgu-b with blocking CRs

apiVersion: ran.openshift.io/v1alpha1
kind: ClusterGroupUpgrade
metadata:
  name: cgu-b
  namespace: default
spec:
  blockingCRs:
  - name: cgu-a
    namespace: default
  clusters:
  - spoke4
  - spoke5
  enable: true
  managedPolicies:
  - policy1-common-cluster-version-policy
  - policy2-common-pao-sub-policy
  - policy3-common-ptp-sub-policy
  - policy4-common-sriov-sub-policy
  remediationStrategy:
    maxConcurrency: 1
    timeout: 240
status:
  conditions:
  - message: 'The ClusterGroupUpgrade CR is blocked by other CRs that have not yet
      completed: [cgu-a]' 1
    reason: UpgradeCannotStart
    status: "False"
    type: Ready
  copiedPolicies:
  - cgu-b-policy1-common-cluster-version-policy
  - cgu-b-policy2-common-pao-sub-policy
  - cgu-b-policy3-common-ptp-sub-policy
  - cgu-b-policy4-common-sriov-sub-policy
  managedPoliciesForUpgrade:
  - name: policy1-common-cluster-version-policy
    namespace: default
  - name: policy2-common-pao-sub-policy
    namespace: default
  - name: policy3-common-ptp-sub-policy
    namespace: default
  - name: policy4-common-sriov-sub-policy
    namespace: default
  placementBindings:
  - cgu-b-policy1-common-cluster-version-policy
  - cgu-b-policy2-common-pao-sub-policy
  - cgu-b-policy3-common-ptp-sub-policy
  - cgu-b-policy4-common-sriov-sub-policy
  placementRules:
  - cgu-b-policy1-common-cluster-version-policy
  - cgu-b-policy2-common-pao-sub-policy
  - cgu-b-policy3-common-ptp-sub-policy
  - cgu-b-policy4-common-sriov-sub-policy
  remediationPlan:
  - - spoke4
  - - spoke5
  status: {}

1: Shows the list of blocking CRs.

Example for cgu-c with blocking CRs

apiVersion: ran.openshift.io/v1alpha1
kind: ClusterGroupUpgrade
metadata:
  name: cgu-c
  namespace: default
spec:
  clusters:
  - spoke6
  enable: true
  managedPolicies:
  - policy1-common-cluster-version-policy
  - policy2-common-pao-sub-policy
  - policy3-common-ptp-sub-policy
  - policy4-common-sriov-sub-policy
  remediationStrategy:
    maxConcurrency: 1
    timeout: 240
status:
  conditions:
  - message: The ClusterGroupUpgrade CR has upgrade policies that are still non compliant 1
    reason: UpgradeNotCompleted
    status: "False"
    type: Ready
  copiedPolicies:
  - cgu-c-policy1-common-cluster-version-policy
  - cgu-c-policy4-common-sriov-sub-policy
  managedPoliciesCompliantBeforeUpgrade:
  - policy2-common-pao-sub-policy
  - policy3-common-ptp-sub-policy
  managedPoliciesForUpgrade:
  - name: policy1-common-cluster-version-policy
    namespace: default
  - name: policy4-common-sriov-sub-policy
    namespace: default
  placementBindings:
  - cgu-c-policy1-common-cluster-version-policy
  - cgu-c-policy4-common-sriov-sub-policy
  placementRules:
  - cgu-c-policy1-common-cluster-version-policy
  - cgu-c-policy4-common-sriov-sub-policy
  remediationPlan:
  - - spoke6
  status:
    currentBatch: 1
    remediationPlanForBatch:
      spoke6: 0

1: The cgu-c update does not have any blocking CRs.

18.11.6. Update policies on managed clusters

The Topology Aware Lifecycle Manager (TALM) remediates a set of inform policies for the clusters specified in the ClusterGroupUpgrade CR. TALM remediates inform policies by making enforce copies of the managed RHACM policies. Each copied policy has its own corresponding RHACM placement rule and RHACM placement binding.

One by one, TALM adds each cluster from the current batch to the placement rule that corresponds with the applicable managed policy. If a cluster is already compliant with a policy, TALM skips applying that policy on the compliant cluster. TALM then moves on to applying the next policy to the non-compliant cluster. After TALM completes the updates in a batch, all clusters are removed from the placement rules associated with the copied policies. Then, the update of the next batch starts.

If a spoke cluster does not report any compliant state to RHACM, the managed policies on the hub cluster can be missing status information that TALM needs. TALM handles these cases in the following ways:

If a policy’s status.compliant field is missing, TALM ignores the policy and adds a log entry. Then, TALM continues looking at the policy’s status.status field.
If a policy’s status.status is missing, TALM produces an error.
If a cluster’s compliance status is missing in the policy’s status.status field, TALM considers that cluster to be non-compliant with that policy.

The ClusterGroupUpgrade CR’s batchTimeoutAction determines what happens if an upgrade fails for a cluster. You can specify continue to skip the failing cluster and continue to upgrade other clusters, or specify abort to stop the policy remediation for all clusters. Once the timeout elapses, TALM removes all enforce policies to ensure that no further updates are made to clusters.

Example upgrade policy

apiVersion: policy.open-cluster-management.io/v1
kind: Policy
metadata:
  name: ocp-4.4.14.4
  namespace: platform-upgrade
spec:
  disabled: false
  policy-templates:
  - objectDefinition:
      apiVersion: policy.open-cluster-management.io/v1
      kind: ConfigurationPolicy
      metadata:
        name: upgrade
      spec:
        namespaceselector:
          exclude:
          - kube-*
          include:
          - '*'
        object-templates:
        - complianceType: musthave
          objectDefinition:
            apiVersion: config.openshift.io/v1
            kind: ClusterVersion
            metadata:
              name: version
            spec:
              channel: stable-4.14
              desiredUpdate:
                version: 4.4.14.4
              upstream: https://api.openshift.com/api/upgrades_info/v1/graph
            status:
              history:
                - state: Completed
                  version: 4.4.14.4
        remediationAction: inform
        severity: low
  remediationAction: inform

For more information about RHACM policies, see Policy overview.

Additional resources

For more information about the PolicyGenTemplate CRD, see About the PolicyGenTemplate CRD.

18.11.6.1. Configuring Operator subscriptions for managed clusters that you install with TALM

Topology Aware Lifecycle Manager (TALM) can only approve the install plan for an Operator if the Subscription custom resource (CR) of the Operator contains the status.state.AtLatestKnown field.

Procedure

Add the status.state.AtLatestKnown field to the Subscription CR of the Operator:

Example Subscription CR

apiVersion: operators.coreos.com/v1alpha1
kind: Subscription
metadata:
  name: cluster-logging
  namespace: openshift-logging
  annotations:
    ran.openshift.io/ztp-deploy-wave: "2"
spec:
  channel: "stable"
  name: cluster-logging
  source: redhat-operators
  sourceNamespace: openshift-marketplace
  installPlanApproval: Manual
status:
  state: AtLatestKnown 1

1: The status.state: AtLatestKnown field is used for the latest Operator version available from the Operator catalog.

Note

When a new version of the Operator is available in the registry, the associated policy becomes non-compliant.

Apply the changed Subscription policy to your managed clusters with a ClusterGroupUpgrade CR.

18.11.6.2. Applying update policies to managed clusters

You can update your managed clusters by applying your policies.

Prerequisites

Install the Topology Aware Lifecycle Manager (TALM).
Provision one or more managed clusters.
Log in as a user with cluster-admin privileges.
Create RHACM policies in the hub cluster.

Procedure

Save the contents of the ClusterGroupUpgrade CR in the cgu-1.yaml file.

apiVersion: ran.openshift.io/v1alpha1
kind: ClusterGroupUpgrade
metadata:
  name: cgu-1
  namespace: default
spec:
  managedPolicies: 1
    - policy1-common-cluster-version-policy
    - policy2-common-nto-sub-policy
    - policy3-common-ptp-sub-policy
    - policy4-common-sriov-sub-policy
  enable: false
  clusters: 2
  - spoke1
  - spoke2
  - spoke5
  - spoke6
  remediationStrategy:
    maxConcurrency: 2 3
    timeout: 240 4
  batchTimeoutAction: 5

1: The name of the policies to apply.
2: The list of clusters to update.
3: The maxConcurrency field signifies the number of clusters updated at the same time.
4: The update timeout in minutes.
5: Controls what happens if a batch times out. Possible values are abort or continue. If unspecified, the default is continue.

Create the ClusterGroupUpgrade CR by running the following command:

$ oc create -f cgu-1.yaml

Check if the ClusterGroupUpgrade CR was created in the hub cluster by running the following command:

$ oc get cgu --all-namespaces

Example output

NAMESPACE   NAME  AGE  STATE      DETAILS
default     cgu-1 8m55 NotEnabled Not Enabled

Check the status of the update by running the following command:

$ oc get cgu -n default cgu-1 -ojsonpath='{.status}' | jq

Example output

{
  "computedMaxConcurrency": 2,
  "conditions": [
    {
      "lastTransitionTime": "2022-02-25T15:34:07Z",
      "message": "Not enabled", 1
      "reason": "NotEnabled",
      "status": "False",
      "type": "Progressing"
    }
  ],
  "copiedPolicies": [
    "cgu-policy1-common-cluster-version-policy",
    "cgu-policy2-common-nto-sub-policy",
    "cgu-policy3-common-ptp-sub-policy",
    "cgu-policy4-common-sriov-sub-policy"
  ],
  "managedPoliciesContent": {
    "policy1-common-cluster-version-policy": "null",
    "policy2-common-nto-sub-policy": "[{\"kind\":\"Subscription\",\"name\":\"node-tuning-operator\",\"namespace\":\"openshift-cluster-node-tuning-operator\"}]",
    "policy3-common-ptp-sub-policy": "[{\"kind\":\"Subscription\",\"name\":\"ptp-operator-subscription\",\"namespace\":\"openshift-ptp\"}]",
    "policy4-common-sriov-sub-policy": "[{\"kind\":\"Subscription\",\"name\":\"sriov-network-operator-subscription\",\"namespace\":\"openshift-sriov-network-operator\"}]"
  },
  "managedPoliciesForUpgrade": [
    {
      "name": "policy1-common-cluster-version-policy",
      "namespace": "default"
    },
    {
      "name": "policy2-common-nto-sub-policy",
      "namespace": "default"
    },
    {
      "name": "policy3-common-ptp-sub-policy",
      "namespace": "default"
    },
    {
      "name": "policy4-common-sriov-sub-policy",
      "namespace": "default"
    }
  ],
  "managedPoliciesNs": {
    "policy1-common-cluster-version-policy": "default",
    "policy2-common-nto-sub-policy": "default",
    "policy3-common-ptp-sub-policy": "default",
    "policy4-common-sriov-sub-policy": "default"
  },
  "placementBindings": [
    "cgu-policy1-common-cluster-version-policy",
    "cgu-policy2-common-nto-sub-policy",
    "cgu-policy3-common-ptp-sub-policy",
    "cgu-policy4-common-sriov-sub-policy"
  ],
  "placementRules": [
    "cgu-policy1-common-cluster-version-policy",
    "cgu-policy2-common-nto-sub-policy",
    "cgu-policy3-common-ptp-sub-policy",
    "cgu-policy4-common-sriov-sub-policy"
  ],
  "precaching": {
    "spec": {}
  },
  "remediationPlan": [
    [
      "spoke1",
      "spoke2"
    ],
    [
      "spoke5",
      "spoke6"
    ]
  ],
  "status": {}
}

1: The spec.enable field in the ClusterGroupUpgrade CR is set to false.

Check the status of the policies by running the following command:

$ oc get policies -A

Example output

NAMESPACE   NAME                                                 REMEDIATION ACTION   COMPLIANCE STATE   AGE
default     cgu-policy1-common-cluster-version-policy            enforce                                 17m 1
default     cgu-policy2-common-nto-sub-policy                    enforce                                 17m
default     cgu-policy3-common-ptp-sub-policy                    enforce                                 17m
default     cgu-policy4-common-sriov-sub-policy                  enforce                                 17m
default     policy1-common-cluster-version-policy                inform               NonCompliant       15h
default     policy2-common-nto-sub-policy                        inform               NonCompliant       15h
default     policy3-common-ptp-sub-policy                        inform               NonCompliant       18m
default     policy4-common-sriov-sub-policy                      inform               NonCompliant       18m

1: The spec.remediationAction field of policies currently applied on the clusters is set to enforce. The managed policies in inform mode from the ClusterGroupUpgrade CR remain in inform mode during the update.

Change the value of the spec.enable field to true by running the following command:

$ oc --namespace=default patch clustergroupupgrade.ran.openshift.io/cgu-1 \
--patch '{"spec":{"enable":true}}' --type=merge

Verification

Check the status of the update again by running the following command:

$ oc get cgu -n default cgu-1 -ojsonpath='{.status}' | jq

Example output

{
  "computedMaxConcurrency": 2,
  "conditions": [ 1
    {
      "lastTransitionTime": "2022-02-25T15:33:07Z",
      "message": "All selected clusters are valid",
      "reason": "ClusterSelectionCompleted",
      "status": "True",
      "type": "ClustersSelected",
      "lastTransitionTime": "2022-02-25T15:33:07Z",
      "message": "Completed validation",
      "reason": "ValidationCompleted",
      "status": "True",
      "type": "Validated",
      "lastTransitionTime": "2022-02-25T15:34:07Z",
      "message": "Remediating non-compliant policies",
      "reason": "InProgress",
      "status": "True",
      "type": "Progressing"
    }
  ],
  "copiedPolicies": [
    "cgu-policy1-common-cluster-version-policy",
    "cgu-policy2-common-nto-sub-policy",
    "cgu-policy3-common-ptp-sub-policy",
    "cgu-policy4-common-sriov-sub-policy"
  ],
  "managedPoliciesContent": {
    "policy1-common-cluster-version-policy": "null",
    "policy2-common-nto-sub-policy": "[{\"kind\":\"Subscription\",\"name\":\"node-tuning-operator\",\"namespace\":\"openshift-cluster-node-tuning-operator\"}]",
    "policy3-common-ptp-sub-policy": "[{\"kind\":\"Subscription\",\"name\":\"ptp-operator-subscription\",\"namespace\":\"openshift-ptp\"}]",
    "policy4-common-sriov-sub-policy": "[{\"kind\":\"Subscription\",\"name\":\"sriov-network-operator-subscription\",\"namespace\":\"openshift-sriov-network-operator\"}]"
  },
  "managedPoliciesForUpgrade": [
    {
      "name": "policy1-common-cluster-version-policy",
      "namespace": "default"
    },
    {
      "name": "policy2-common-nto-sub-policy",
      "namespace": "default"
    },
    {
      "name": "policy3-common-ptp-sub-policy",
      "namespace": "default"
    },
    {
      "name": "policy4-common-sriov-sub-policy",
      "namespace": "default"
    }
  ],
  "managedPoliciesNs": {
    "policy1-common-cluster-version-policy": "default",
    "policy2-common-nto-sub-policy": "default",
    "policy3-common-ptp-sub-policy": "default",
    "policy4-common-sriov-sub-policy": "default"
  },
  "placementBindings": [
    "cgu-policy1-common-cluster-version-policy",
    "cgu-policy2-common-nto-sub-policy",
    "cgu-policy3-common-ptp-sub-policy",
    "cgu-policy4-common-sriov-sub-policy"
  ],
  "placementRules": [
    "cgu-policy1-common-cluster-version-policy",
    "cgu-policy2-common-nto-sub-policy",
    "cgu-policy3-common-ptp-sub-policy",
    "cgu-policy4-common-sriov-sub-policy"
  ],
  "precaching": {
    "spec": {}
  },
  "remediationPlan": [
    [
      "spoke1",
      "spoke2"
    ],
    [
      "spoke5",
      "spoke6"
    ]
  ],
  "status": {
    "currentBatch": 1,
    "currentBatchStartedAt": "2022-02-25T15:54:16Z",
    "remediationPlanForBatch": {
      "spoke1": 0,
      "spoke2": 1
    },
    "startedAt": "2022-02-25T15:54:16Z"
  }
}

1: Reflects the update progress of the current batch. Run this command again to receive updated information about the progress.

If the policies include Operator subscriptions, you can check the installation progress directly on the single-node cluster.
1. Export the KUBECONFIG file of the single-node cluster you want to check the installation progress for by running the following command:
```
$ export KUBECONFIG=<cluster_kubeconfig_absolute_path>
```
2. Check all the subscriptions present on the single-node cluster and look for the one in the policy you are trying to install through the ClusterGroupUpgrade CR by running the following command:
```
$ oc get subs -A | grep -i <subscription_name>
```
  Example output for cluster-logging policy
```
NAMESPACE                              NAME                         PACKAGE                      SOURCE             CHANNEL
openshift-logging                      cluster-logging              cluster-logging              redhat-operators   stable
```

If one of the managed policies includes a ClusterVersion CR, check the status of platform updates in the current batch by running the following command against the spoke cluster:

$ oc get clusterversion

Example output

NAME      VERSION   AVAILABLE   PROGRESSING   SINCE   STATUS
version   4.4.14.5     True        True          43s     Working towards 4.4.14.7: 71 of 735 done (9% complete)

Check the Operator subscription by running the following command:

$ oc get subs -n <operator-namespace> <operator-subscription> -ojsonpath="{.status}"

Check the install plans present on the single-node cluster that is associated with the desired subscription by running the following command:
```
$ oc get installplan -n <subscription_namespace>
```
Example output for cluster-logging Operator
```
NAMESPACE                              NAME            CSV                                 APPROVAL   APPROVED
openshift-logging                      install-6khtw   cluster-logging.5.3.3-4             Manual     true 1
```
1
The install plans have their Approval field set to Manual and their Approved field changes from false to true after TALM approves the install plan.
Note
When TALM is remediating a policy containing a subscription, it automatically approves any install plans attached to that subscription. Where multiple install plans are needed to get the operator to the latest known version, TALM might approve multiple install plans, upgrading through one or more intermediate versions to get to the final version.
Check if the cluster service version for the Operator of the policy that the ClusterGroupUpgrade is installing reached the Succeeded phase by running the following command:
```
$ oc get csv -n <operator_namespace>
```
Example output for OpenShift Logging Operator
```
NAME                    DISPLAY                     VERSION   REPLACES   PHASE
cluster-logging.5.4.2   Red Hat OpenShift Logging   5.4.2                Succeeded
```

18.11.7. Creating a backup of cluster resources before upgrade

For single-node OpenShift, the Topology Aware Lifecycle Manager (TALM) can create a backup of a deployment before an upgrade. If the upgrade fails, you can recover the previous version and restore a cluster to a working state without requiring a reprovision of applications.

To use the backup feature you first create a ClusterGroupUpgrade CR with the backup field set to true. To ensure that the contents of the backup are up to date, the backup is not taken until you set the enable field in the ClusterGroupUpgrade CR to true.

TALM uses the BackupSucceeded condition to report the status and reasons as follows:

true
Backup is completed for all clusters or the backup run has completed but failed for one or more clusters. If backup fails for any cluster, the update does not proceed for that cluster.
false
Backup is still in progress for one or more clusters or has failed for all clusters. The backup process running in the spoke clusters can have the following statuses:
- PreparingToStart
  The first reconciliation pass is in progress. The TALM deletes any spoke backup namespace and hub view resources that have been created in a failed upgrade attempt.
- Starting
  The backup prerequisites and backup job are being created.
- Active
  The backup is in progress.
- Succeeded
  The backup succeeded.
- BackupTimeout
  Artifact backup is partially done.
- UnrecoverableError
  The backup has ended with a non-zero exit code.

Note

If the backup of a cluster fails and enters the BackupTimeout or UnrecoverableError state, the cluster update does not proceed for that cluster. Updates to other clusters are not affected and continue.

18.11.7.1. Creating a ClusterGroupUpgrade CR with backup

You can create a backup of a deployment before an upgrade on single-node OpenShift clusters. If the upgrade fails you can use the upgrade-recovery.sh script generated by Topology Aware Lifecycle Manager (TALM) to return the system to its preupgrade state. The backup consists of the following items:

Cluster backup: A snapshot of etcd and static pod manifests.
Content backup: Backups of folders, for example, /etc, /usr/local, /var/lib/kubelet.
Changed files backup: Any files managed by machine-config that have been changed.
Deployment: A pinned ostree deployment.
Images (Optional): Any container images that are in use.

Prerequisites

Install the Topology Aware Lifecycle Manager (TALM).
Provision one or more managed clusters.
Log in as a user with cluster-admin privileges.
Install Red Hat Advanced Cluster Management (RHACM).

Note

It is highly recommended that you create a recovery partition. The following is an example SiteConfig custom resource (CR) for a recovery partition of 50 GB:

nodes:
    - hostName: "node-1.example.com"
    role: "master"
    rootDeviceHints:
        hctl: "0:2:0:0"
        deviceName: /dev/disk/by-id/scsi-3600508b400105e210000900000490000
...
    #Disk /dev/disk/by-id/scsi-3600508b400105e210000900000490000:
    #893.3 GiB, 959119884288 bytes, 1873281024 sectors
    diskPartition:
        - device: /dev/disk/by-id/scsi-3600508b400105e210000900000490000
        partitions:
        - mount_point: /var/recovery
            size: 51200
            start: 800000

Procedure

Save the contents of the ClusterGroupUpgrade CR with the backup and enable fields set to true in the clustergroupupgrades-group-du.yaml file:

apiVersion: ran.openshift.io/v1alpha1
kind: ClusterGroupUpgrade
metadata:
  name: du-upgrade-4918
  namespace: ztp-group-du-sno
spec:
  preCaching: true
  backup: true
  clusters:
  - cnfdb1
  - cnfdb2
  enable: true
  managedPolicies:
  - du-upgrade-platform-upgrade
  remediationStrategy:
    maxConcurrency: 2
    timeout: 240

To start the update, apply the ClusterGroupUpgrade CR by running the following command:
```
$ oc apply -f clustergroupupgrades-group-du.yaml
```

Verification

Check the status of the upgrade in the hub cluster by running the following command:

$ oc get cgu -n ztp-group-du-sno du-upgrade-4918 -o jsonpath='{.status}'

Example output

{
    "backup": {
        "clusters": [
            "cnfdb2",
            "cnfdb1"
    ],
    "status": {
        "cnfdb1": "Succeeded",
        "cnfdb2": "Failed" 1
    }
},
"computedMaxConcurrency": 1,
"conditions": [
    {
        "lastTransitionTime": "2022-04-05T10:37:19Z",
        "message": "Backup failed for 1 cluster", 2
        "reason": "PartiallyDone", 3
        "status": "True", 4
        "type": "Succeeded"
    }
],
"precaching": {
    "spec": {}
},
"status": {}

1: Backup has failed for one cluster.
2: The message confirms that the backup failed for one cluster.
3: The backup was partially successful.
4: The backup process has finished.

18.11.7.2. Recovering a cluster after a failed upgrade

If an upgrade of a cluster fails, you can manually log in to the cluster and use the backup to return the cluster to its preupgrade state. There are two stages:

Rollback: If the attempted upgrade included a change to the platform OS deployment, you must roll back to the previous version before running the recovery script.

Important

A rollback is only applicable to upgrades from TALM and single-node OpenShift. This process does not apply to rollbacks from any other upgrade type.

Recovery: The recovery shuts down containers and uses files from the backup partition to relaunch containers and restore clusters.

Prerequisites

Install the Topology Aware Lifecycle Manager (TALM).
Provision one or more managed clusters.
Install Red Hat Advanced Cluster Management (RHACM).
Log in as a user with cluster-admin privileges.
Run an upgrade that is configured for backup.

Procedure

Delete the previously created ClusterGroupUpgrade custom resource (CR) by running the following command:
```
$ oc delete cgu/du-upgrade-4918 -n ztp-group-du-sno
```
Log in to the cluster that you want to recover.

Check the status of the platform OS deployment by running the following command:

$ ostree admin status

Example outputs

[root@lab-test-spoke2-node-0 core]# ostree admin status
* rhcos c038a8f08458bbed83a77ece033ad3c55597e3f64edad66ea12fda18cbdceaf9.0
    Version: 49.84.202202230006-0
    Pinned: yes 1
    origin refspec: c038a8f08458bbed83a77ece033ad3c55597e3f64edad66ea12fda18cbdceaf9

1: The current deployment is pinned. A platform OS deployment rollback is not necessary.

[root@lab-test-spoke2-node-0 core]# ostree admin status
* rhcos f750ff26f2d5550930ccbe17af61af47daafc8018cd9944f2a3a6269af26b0fa.0
    Version: 410.84.202204050541-0
    origin refspec: f750ff26f2d5550930ccbe17af61af47daafc8018cd9944f2a3a6269af26b0fa
rhcos ad8f159f9dc4ea7e773fd9604c9a16be0fe9b266ae800ac8470f63abc39b52ca.0 (rollback) 1
    Version: 410.84.202203290245-0
    Pinned: yes 2
    origin refspec: ad8f159f9dc4ea7e773fd9604c9a16be0fe9b266ae800ac8470f63abc39b52ca

1: This platform OS deployment is marked for rollback.
2: The previous deployment is pinned and can be rolled back.

To trigger a rollback of the platform OS deployment, run the following command:
```
$ rpm-ostree rollback -r
```
The first phase of the recovery shuts down containers and restores files from the backup partition to the targeted directories. To begin the recovery, run the following command:
```
$ /var/recovery/upgrade-recovery.sh
```
When prompted, reboot the cluster by running the following command:
```
$ systemctl reboot
```
After the reboot, restart the recovery by running the following command:
```
$ /var/recovery/upgrade-recovery.sh  --resume
```

Note

If the recovery utility fails, you can retry with the --restart option:

$ /var/recovery/upgrade-recovery.sh --restart

Verification

To check the status of the recovery run the following command:

$ oc get clusterversion,nodes,clusteroperator

Example output

NAME                                         VERSION   AVAILABLE   PROGRESSING   SINCE   STATUS
clusterversion.config.openshift.io/version   4.4.14.23    True        False         86d     Cluster version is 4.4.14.23 1


NAME                          STATUS   ROLES           AGE   VERSION
node/lab-test-spoke1-node-0   Ready    master,worker   86d   v1.22.3+b93fd35 2

NAME                                                                           VERSION   AVAILABLE   PROGRESSING   DEGRADED   SINCE   MESSAGE
clusteroperator.config.openshift.io/authentication                             4.4.14.23    True        False         False      2d7h    3
clusteroperator.config.openshift.io/baremetal                                  4.4.14.23    True        False         False      86d


..............

1: The cluster version is available and has the correct version.
2: The node status is Ready.
3: The ClusterOperator object’s availability is True.

18.11.8. Using the container image pre-cache feature

Single-node OpenShift clusters might have limited bandwidth to access the container image registry, which can cause a timeout before the updates are completed.

Note

The time of the update is not set by TALM. You can apply the ClusterGroupUpgrade CR at the beginning of the update by manual application or by external automation.

The container image pre-caching starts when the preCaching field is set to true in the ClusterGroupUpgrade CR.

TALM uses the PrecacheSpecValid condition to report status information as follows:

true
The pre-caching spec is valid and consistent.
false
The pre-caching spec is incomplete.

TALM uses the PrecachingSucceeded condition to report status information as follows:

true
TALM has concluded the pre-caching process. If pre-caching fails for any cluster, the update fails for that cluster but proceeds for all other clusters. A message informs you if pre-caching has failed for any clusters.
false
Pre-caching is still in progress for one or more clusters or has failed for all clusters.

After a successful pre-caching process, you can start remediating policies. The remediation actions start when the enable field is set to true. If there is a pre-caching failure on a cluster, the upgrade fails for that cluster. The upgrade process continues for all other clusters that have a successful pre-cache.

The pre-caching process can be in the following statuses:

NotStarted
This is the initial state all clusters are automatically assigned to on the first reconciliation pass of the ClusterGroupUpgrade CR. In this state, TALM deletes any pre-caching namespace and hub view resources of spoke clusters that remain from previous incomplete updates. TALM then creates a new ManagedClusterView resource for the spoke pre-caching namespace to verify its deletion in the PrecachePreparing state.
PreparingToStart
Cleaning up any remaining resources from previous incomplete updates is in progress.
Starting
Pre-caching job prerequisites and the job are created.
Active
The job is in "Active" state.
Succeeded
The pre-cache job succeeded.
PrecacheTimeout
The artifact pre-caching is partially done.
UnrecoverableError
The job ends with a non-zero exit code.

18.11.8.1. Using the container image pre-cache filter

The pre-cache feature typically downloads more images than a cluster needs for an update. You can control which pre-cache images are downloaded to a cluster. This decreases download time, and saves bandwidth and storage.

You can see a list of all images to be downloaded using the following command:

$ oc adm release info <ocp-version>

The following ConfigMap example shows how you can exclude images using the excludePrecachePatterns field.

apiVersion: v1
kind: ConfigMap
metadata:
  name: cluster-group-upgrade-overrides
data:
  excludePrecachePatterns: |
    azure 1
    aws
    vsphere
    alibaba

1: TALM excludes all images with names that include any of the patterns listed here.

18.11.8.2. Creating a ClusterGroupUpgrade CR with pre-caching

For single-node OpenShift, the pre-cache feature allows the required container images to be present on the spoke cluster before the update starts.

Note

For pre-caching, TALM uses the spec.remediationStrategy.timeout value from the ClusterGroupUpgrade CR. You must set a timeout value that allows sufficient time for the pre-caching job to complete. When you enable the ClusterGroupUpgrade CR after pre-caching has completed, you can change the timeout value to a duration that is appropriate for the update.

Prerequisites

Install the Topology Aware Lifecycle Manager (TALM).
Provision one or more managed clusters.
Log in as a user with cluster-admin privileges.

Procedure

Save the contents of the ClusterGroupUpgrade CR with the preCaching field set to true in the clustergroupupgrades-group-du.yaml file:

apiVersion: ran.openshift.io/v1alpha1
kind: ClusterGroupUpgrade
metadata:
  name: du-upgrade-4918
  namespace: ztp-group-du-sno
spec:
  preCaching: true 1
  clusters:
  - cnfdb1
  - cnfdb2
  enable: false
  managedPolicies:
  - du-upgrade-platform-upgrade
  remediationStrategy:
    maxConcurrency: 2
    timeout: 240

1: The preCaching field is set to true, which enables TALM to pull the container images before starting the update.

When you want to start pre-caching, apply the ClusterGroupUpgrade CR by running the following command:
```
$ oc apply -f clustergroupupgrades-group-du.yaml
```

Verification

Check if the ClusterGroupUpgrade CR exists in the hub cluster by running the following command:

$ oc get cgu -A

Example output

NAMESPACE          NAME              AGE   STATE        DETAILS
ztp-group-du-sno   du-upgrade-4918   10s   InProgress   Precaching is required and not done 1

1: The CR is created.

Check the status of the pre-caching task by running the following command:

$ oc get cgu -n ztp-group-du-sno du-upgrade-4918 -o jsonpath='{.status}'

Example output

{
  "conditions": [
    {
      "lastTransitionTime": "2022-01-27T19:07:24Z",
      "message": "Precaching is required and not done",
      "reason": "InProgress",
      "status": "False",
      "type": "PrecachingSucceeded"
    },
    {
      "lastTransitionTime": "2022-01-27T19:07:34Z",
      "message": "Pre-caching spec is valid and consistent",
      "reason": "PrecacheSpecIsWellFormed",
      "status": "True",
      "type": "PrecacheSpecValid"
    }
  ],
  "precaching": {
    "clusters": [
      "cnfdb1" 1
      "cnfdb2"
    ],
    "spec": {
      "platformImage": "image.example.io"},
    "status": {
      "cnfdb1": "Active"
      "cnfdb2": "Succeeded"}
    }
}

1: Displays the list of identified clusters.

Check the status of the pre-caching job by running the following command on the spoke cluster:

$ oc get jobs,pods -n openshift-talo-pre-cache

Example output

NAME                  COMPLETIONS   DURATION   AGE
job.batch/pre-cache   0/1           3m10s      3m10s

NAME                     READY   STATUS    RESTARTS   AGE
pod/pre-cache--1-9bmlr   1/1     Running   0          3m10s

Check the status of the ClusterGroupUpgrade CR by running the following command:

$ oc get cgu -n ztp-group-du-sno du-upgrade-4918 -o jsonpath='{.status}'

Example output

"conditions": [
    {
      "lastTransitionTime": "2022-01-27T19:30:41Z",
      "message": "The ClusterGroupUpgrade CR has all clusters compliant with all the managed policies",
      "reason": "UpgradeCompleted",
      "status": "True",
      "type": "Ready"
    },
    {
      "lastTransitionTime": "2022-01-27T19:28:57Z",
      "message": "Precaching is completed",
      "reason": "PrecachingCompleted",
      "status": "True",
      "type": "PrecachingSucceeded" 1
    }

1: The pre-cache tasks are done.

18.11.9. Troubleshooting the Topology Aware Lifecycle Manager

The Topology Aware Lifecycle Manager (TALM) is an OpenShift Container Platform Operator that remediates RHACM policies. When issues occur, use the oc adm must-gather command to gather details and logs and to take steps in debugging the issues.

For more information about related topics, see the following documentation:

Red Hat Advanced Cluster Management for Kubernetes 2.4 Support Matrix
Red Hat Advanced Cluster Management Troubleshooting
The "Troubleshooting Operator issues" section

18.11.9.1. General troubleshooting

You can determine the cause of the problem by reviewing the following questions:

Is the configuration that you are applying supported?
- Are the RHACM and the OpenShift Container Platform versions compatible?
- Are the TALM and RHACM versions compatible?
Which of the following components is causing the problem?

To ensure that the ClusterGroupUpgrade configuration is functional, you can do the following:

Create the ClusterGroupUpgrade CR with the spec.enable field set to false.
Wait for the status to be updated and go through the troubleshooting questions.
If everything looks as expected, set the spec.enable field to true in the ClusterGroupUpgrade CR.

Warning

After you set the spec.enable field to true in the ClusterUpgradeGroup CR, the update procedure starts and you cannot edit the CR’s spec fields anymore.

18.11.9.2. Cannot modify the ClusterUpgradeGroup CR

Issue

You cannot edit the ClusterUpgradeGroup CR after enabling the update.

Resolution

Restart the procedure by performing the following steps:

Remove the old ClusterGroupUpgrade CR by running the following command:

$ oc delete cgu -n <ClusterGroupUpgradeCR_namespace> <ClusterGroupUpgradeCR_name>

Check and fix the existing issues with the managed clusters and policies.
1. Ensure that all the clusters are managed clusters and available.
2. Ensure that all the policies exist and have the spec.remediationAction field set to inform.
Create a new ClusterGroupUpgrade CR with the correct configurations.
```
$ oc apply -f <ClusterGroupUpgradeCR_YAML>
```

18.11.9.3. Managed policies

Checking managed policies on the system

Issue

You want to check if you have the correct managed policies on the system.

Resolution

Run the following command:

$ oc get cgu lab-upgrade -ojsonpath='{.spec.managedPolicies}'

Example output

["group-du-sno-validator-du-validator-policy", "policy2-common-nto-sub-policy", "policy3-common-ptp-sub-policy"]

Checking remediationAction mode

Issue

You want to check if the remediationAction field is set to inform in the spec of the managed policies.

Resolution

Run the following command:

$ oc get policies --all-namespaces

Example output

NAMESPACE   NAME                                                 REMEDIATION ACTION   COMPLIANCE STATE   AGE
default     policy1-common-cluster-version-policy                inform               NonCompliant       5d21h
default     policy2-common-nto-sub-policy                        inform               Compliant          5d21h
default     policy3-common-ptp-sub-policy                        inform               NonCompliant       5d21h
default     policy4-common-sriov-sub-policy                      inform               NonCompliant       5d21h

Checking policy compliance state

Issue

You want to check the compliance state of policies.

Resolution

Run the following command:

$ oc get policies --all-namespaces

Example output

NAMESPACE   NAME                                                 REMEDIATION ACTION   COMPLIANCE STATE   AGE
default     policy1-common-cluster-version-policy                inform               NonCompliant       5d21h
default     policy2-common-nto-sub-policy                        inform               Compliant          5d21h
default     policy3-common-ptp-sub-policy                        inform               NonCompliant       5d21h
default     policy4-common-sriov-sub-policy                      inform               NonCompliant       5d21h

18.11.9.4. Clusters

Checking if managed clusters are present

Issue

You want to check if the clusters in the ClusterGroupUpgrade CR are managed clusters.

Resolution

Run the following command:

$ oc get managedclusters

Example output

NAME            HUB ACCEPTED   MANAGED CLUSTER URLS                    JOINED   AVAILABLE   AGE
local-cluster   true           https://api.hub.example.com:6443        True     Unknown     13d
spoke1          true           https://api.spoke1.example.com:6443     True     True        13d
spoke3          true           https://api.spoke3.example.com:6443     True     True        27h

Alternatively, check the TALM manager logs:

Get the name of the TALM manager by running the following command:

$ oc get pod -n openshift-operators

Example output

NAME                                                         READY   STATUS    RESTARTS   AGE
cluster-group-upgrades-controller-manager-75bcc7484d-8k8xp   2/2     Running   0          45m

Check the TALM manager logs by running the following command:

$ oc logs -n openshift-operators \
cluster-group-upgrades-controller-manager-75bcc7484d-8k8xp -c manager

Example output

ERROR	controller-runtime.manager.controller.clustergroupupgrade	Reconciler error	{"reconciler group": "ran.openshift.io", "reconciler kind": "ClusterGroupUpgrade", "name": "lab-upgrade", "namespace": "default", "error": "Cluster spoke5555 is not a ManagedCluster"} 1
sigs.k8s.io/controller-runtime/pkg/internal/controller.(*Controller).processNextWorkItem

1: The error message shows that the cluster is not a managed cluster.

Checking if managed clusters are available

Issue

You want to check if the managed clusters specified in the ClusterGroupUpgrade CR are available.

Resolution

Run the following command:

$ oc get managedclusters

Example output

NAME            HUB ACCEPTED   MANAGED CLUSTER URLS                    JOINED   AVAILABLE   AGE
local-cluster   true           https://api.hub.testlab.com:6443        True     Unknown     13d
spoke1          true           https://api.spoke1.testlab.com:6443     True     True        13d 1
spoke3          true           https://api.spoke3.testlab.com:6443     True     True        27h 2

1 2: The value of the AVAILABLE field is True for the managed clusters.

Checking clusterLabelSelector

Issue

You want to check if the clusterLabelSelector field specified in the ClusterGroupUpgrade CR matches at least one of the managed clusters.

Resolution

Run the following command:

$ oc get managedcluster --selector=upgrade=true 1

1: The label for the clusters you want to update is upgrade:true.

Example output

NAME            HUB ACCEPTED   MANAGED CLUSTER URLS                     JOINED    AVAILABLE   AGE
spoke1          true           https://api.spoke1.testlab.com:6443      True     True        13d
spoke3          true           https://api.spoke3.testlab.com:6443      True     True        27h

Checking if canary clusters are present

Issue

You want to check if the canary clusters are present in the list of clusters.

Example ClusterGroupUpgrade CR

spec:
    remediationStrategy:
        canaries:
        - spoke3
        maxConcurrency: 2
        timeout: 240
    clusterLabelSelectors:
      - matchLabels:
          upgrade: true

Resolution

Run the following commands:

$ oc get cgu lab-upgrade -ojsonpath='{.spec.clusters}'

Example output

["spoke1", "spoke3"]

Check if the canary clusters are present in the list of clusters that match clusterLabelSelector labels by running the following command:

$ oc get managedcluster --selector=upgrade=true

Example output

NAME            HUB ACCEPTED   MANAGED CLUSTER URLS   JOINED    AVAILABLE   AGE
spoke1          true           https://api.spoke1.testlab.com:6443   True     True        13d
spoke3          true           https://api.spoke3.testlab.com:6443   True     True        27h

Note

A cluster can be present in spec.clusters and also be matched by the spec.clusterLabelSelector label.

Checking the pre-caching status on spoke clusters

Check the status of pre-caching by running the following command on the spoke cluster:
```
$ oc get jobs,pods -n openshift-talo-pre-cache
```

18.11.9.5. Remediation Strategy

Checking if remediationStrategy is present in the ClusterGroupUpgrade CR

Issue

You want to check if the remediationStrategy is present in the ClusterGroupUpgrade CR.

Resolution

Run the following command:

$ oc get cgu lab-upgrade -ojsonpath='{.spec.remediationStrategy}'

Example output

{"maxConcurrency":2, "timeout":240}

Checking if maxConcurrency is specified in the ClusterGroupUpgrade CR

Issue

You want to check if the maxConcurrency is specified in the ClusterGroupUpgrade CR.

Resolution

Run the following command:

$ oc get cgu lab-upgrade -ojsonpath='{.spec.remediationStrategy.maxConcurrency}'

Example output

18.11.9.6. Topology Aware Lifecycle Manager

Checking condition message and status in the ClusterGroupUpgrade CR

Issue

You want to check the value of the status.conditions field in the ClusterGroupUpgrade CR.

Resolution

Run the following command:

$ oc get cgu lab-upgrade -ojsonpath='{.status.conditions}'

Example output

{"lastTransitionTime":"2022-02-17T22:25:28Z", "message":"Missing managed policies:[policyList]", "reason":"NotAllManagedPoliciesExist", "status":"False", "type":"Validated"}

Checking corresponding copied policies

Issue

You want to check if every policy from status.managedPoliciesForUpgrade has a corresponding policy in status.copiedPolicies.

Resolution

Run the following command:

$ oc get cgu lab-upgrade -oyaml

Example output

status:
  …
  copiedPolicies:
  - lab-upgrade-policy3-common-ptp-sub-policy
  managedPoliciesForUpgrade:
  - name: policy3-common-ptp-sub-policy
    namespace: default

Checking if status.remediationPlan was computed

Issue

You want to check if status.remediationPlan is computed.

Resolution

Run the following command:

$ oc get cgu lab-upgrade -ojsonpath='{.status.remediationPlan}'

Example output

[["spoke2", "spoke3"]]

Errors in the TALM manager container

Issue

You want to check the logs of the manager container of TALM.

Resolution

Run the following command:

$ oc logs -n openshift-operators \
cluster-group-upgrades-controller-manager-75bcc7484d-8k8xp -c manager

Example output

ERROR	controller-runtime.manager.controller.clustergroupupgrade	Reconciler error	{"reconciler group": "ran.openshift.io", "reconciler kind": "ClusterGroupUpgrade", "name": "lab-upgrade", "namespace": "default", "error": "Cluster spoke5555 is not a ManagedCluster"} 1
sigs.k8s.io/controller-runtime/pkg/internal/controller.(*Controller).processNextWorkItem

1: Displays the error.

Clusters are not compliant to some policies after a `ClusterGroupUpgrade` CR has completed

Issue

The policy compliance status that TALM uses to decide if remediation is needed has not yet fully updated for all clusters. This may be because:

The CGU was run too soon after a policy was created or updated.
The remediation of a policy affects the compliance of subsequent policies in the ClusterGroupUpgrade CR.

Resolution

Create and apply a new ClusterGroupUpdate CR with the same specification.

Auto-created `ClusterGroupUpgrade` CR in the GitOps ZTP workflow has no managed policies

Issue: If there are no policies for the managed cluster when the cluster becomes Ready, a ClusterGroupUpgrade CR with no policies is auto-created. Upon completion of the ClusterGroupUpgrade CR, the managed cluster is labeled as ztp-done. If the PolicyGenTemplate CRs were not pushed to the Git repository within the required time after SiteConfig resources were pushed, this might result in no policies being available for the target cluster when the cluster became Ready.
Resolution: Verify that the policies you want to apply are available on the hub cluster, then create a ClusterGroupUpgrade CR with the required policies.

You can either manually create the ClusterGroupUpgrade CR or trigger auto-creation again. To trigger auto-creation of the ClusterGroupUpgrade CR, remove the ztp-done label from the cluster and delete the empty ClusterGroupUpgrade CR that was previously created in the zip-install namespace.

Pre-caching has failed

Issue

Pre-caching might fail for one of the following reasons:

There is not enough free space on the node.
For a disconnected environment, the pre-cache image has not been properly mirrored.
There was an issue when creating the pod.

Resolution

To check if pre-caching has failed due to insufficient space, check the log of the pre-caching pod in the node.
1. Find the name of the pod using the following command:
```
$ oc get pods -n openshift-talo-pre-cache
```
2. Check the logs to see if the error is related to insufficient space using the following command:
```
$ oc logs -n openshift-talo-pre-cache <pod name>
```
If there is no log, check the pod status using the following command:
```
$ oc describe pod -n openshift-talo-pre-cache <pod name>
```
If the pod does not exist, check the job status to see why it could not create a pod using the following command:
```
$ oc describe job -n openshift-talo-pre-cache pre-cache
```

Additional resources

For information about troubleshooting, see OpenShift Container Platform Troubleshooting Operator Issues.
For more information about using Topology Aware Lifecycle Manager in the ZTP workflow, see Updating managed policies with Topology Aware Lifecycle Manager.
For more information about the PolicyGenTemplate CRD, see About the PolicyGenTemplate CRD

18.12. Updating managed clusters in a disconnected environment with the Topology Aware Lifecycle Manager

You can use the Topology Aware Lifecycle Manager (TALM) to manage the software lifecycle of OpenShift Container Platform managed clusters. TALM uses Red Hat Advanced Cluster Management (RHACM) policies to perform changes on the target clusters.

Additional resources

For more information about the Topology Aware Lifecycle Manager, see About the Topology Aware Lifecycle Manager.

18.12.1. Updating clusters in a disconnected environment

You can upgrade managed clusters and Operators for managed clusters that you have deployed using GitOps Zero Touch Provisioning (ZTP) and Topology Aware Lifecycle Manager (TALM).

18.12.1.1. Setting up the environment

TALM can perform both platform and Operator updates.

You must mirror both the platform image and Operator images that you want to update to in your mirror registry before you can use TALM to update your disconnected clusters. Complete the following steps to mirror the images:

For platform updates, you must perform the following steps:
1. Mirror the desired OpenShift Container Platform image repository. Ensure that the desired platform image is mirrored by following the "Mirroring the OpenShift Container Platform image repository" procedure linked in the Additional resources. Save the contents of the imageContentSources section in the imageContentSources.yaml file:
  Example output
```
imageContentSources:
 - mirrors:
   - mirror-ocp-registry.ibmcloud.io.cpak:5000/openshift-release-dev/openshift4
   source: quay.io/openshift-release-dev/ocp-release
 - mirrors:
   - mirror-ocp-registry.ibmcloud.io.cpak:5000/openshift-release-dev/openshift4
   source: quay.io/openshift-release-dev/ocp-v4.0-art-dev
```
2. Save the image signature of the desired platform image that was mirrored. You must add the image signature to the PolicyGenTemplate CR for platform updates. To get the image signature, perform the following steps:
  1. Specify the desired OpenShift Container Platform tag by running the following command:
    $ OCP_RELEASE_NUMBER=<release_version>
  2. Specify the architecture of the cluster by running the following command:
    $ ARCHITECTURE=<cluster_architecture> 1
    1
    Specify the architecture of the cluster, such as x86_64, aarch64, s390x, or ppc64le.
  3. Get the release image digest from Quay by running the following command
    $ DIGEST="$(oc adm release info quay.io/openshift-release-dev/ocp-release:${OCP_RELEASE_NUMBER}-${ARCHITECTURE} | sed -n 's/Pull From: .*@//p')"
  4. Set the digest algorithm by running the following command:
    $ DIGEST_ALGO="${DIGEST%%:*}"
  5. Set the digest signature by running the following command:
    $ DIGEST_ENCODED="${DIGEST#*:}"
  6. Get the image signature from the mirror.openshift.com website by running the following command:
    $ SIGNATURE_BASE64=$(curl -s "https://mirror.openshift.com/pub/openshift-v4/signatures/openshift/release/${DIGEST_ALGO}=${DIGEST_ENCODED}/signature-1" | base64 -w0 && echo)
  7. Save the image signature to the checksum-<OCP_RELEASE_NUMBER>.yaml file by running the following commands:
    $ cat >checksum-${OCP_RELEASE_NUMBER}.yaml <<EOF ${DIGEST_ALGO}-${DIGEST_ENCODED}: ${SIGNATURE_BASE64} EOF
3. Prepare the update graph. You have two options to prepare the update graph:
  1. Use the OpenShift Update Service.
    For more information about how to set up the graph on the hub cluster, see Deploy the operator for OpenShift Update Service and Build the graph data init container.
  2. Make a local copy of the upstream graph. Host the update graph on an http or https server in the disconnected environment that has access to the managed cluster. To download the update graph, use the following command:
    $ curl -s https://api.openshift.com/api/upgrades_info/v1/graph?channel=stable-4.14 -o ~/upgrade-graph_stable-4.14
For Operator updates, you must perform the following task:
- Mirror the Operator catalogs. Ensure that the desired operator images are mirrored by following the procedure in the "Mirroring Operator catalogs for use with disconnected clusters" section.

Additional resources

For more information about how to update GitOps Zero Touch Provisioning (ZTP), see Upgrading GitOps ZTP.
For more information about how to mirror an OpenShift Container Platform image repository, see Mirroring the OpenShift Container Platform image repository.
For more information about how to mirror Operator catalogs for disconnected clusters, see Mirroring Operator catalogs for use with disconnected clusters.
For more information about how to prepare the disconnected environment and mirroring the desired image repository, see Preparing the disconnected environment.
For more information about update channels and releases, see Understanding update channels and releases.

18.12.1.2. Performing a platform update

You can perform a platform update with the TALM.

Prerequisites

Install the Topology Aware Lifecycle Manager (TALM).
Update GitOps Zero Touch Provisioning (ZTP) to the latest version.
Provision one or more managed clusters with GitOps ZTP.
Mirror the desired image repository.
Log in as a user with cluster-admin privileges.
Create RHACM policies in the hub cluster.

Procedure

Create a PolicyGenTemplate CR for the platform update:
1. Save the following contents of the PolicyGenTemplate CR in the du-upgrade.yaml file.
  Example of PolicyGenTemplate for platform update
```
apiVersion: ran.openshift.io/v1
kind: PolicyGenTemplate
metadata:
  name: "du-upgrade"
  namespace: "ztp-group-du-sno"
spec:
  bindingRules:
    group-du-sno: ""
  mcp: "master"
  remediationAction: inform
  sourceFiles:
    - fileName: ImageSignature.yaml 1
      policyName: "platform-upgrade-prep"
      binaryData:
        ${DIGEST_ALGO}-${DIGEST_ENCODED}: ${SIGNATURE_BASE64} 2
    - fileName: DisconnectedICSP.yaml
      policyName: "platform-upgrade-prep"
      metadata:
        name: disconnected-internal-icsp-for-ocp
      spec:
        repositoryDigestMirrors: 3
          - mirrors:
            - quay-intern.example.com/ocp4/openshift-release-dev
            source: quay.io/openshift-release-dev/ocp-release
          - mirrors:
            - quay-intern.example.com/ocp4/openshift-release-dev
            source: quay.io/openshift-release-dev/ocp-v4.0-art-dev
    - fileName: ClusterVersion.yaml 4
      policyName: "platform-upgrade"
      metadata:
        name: version
      spec:
        channel: "stable-4.14"
        upstream: http://upgrade.example.com/images/upgrade-graph_stable-4.14
        desiredUpdate:
          version: 4.14.4
      status:
        history:
          - version: 4.14.4
            state: "Completed"
```
  1
  The ConfigMap CR contains the signature of the desired release image to update to.
  2
  Shows the image signature of the desired OpenShift Container Platform release. Get the signature from the checksum-${OCP_RELEASE_NUMBER}.yaml file you saved when following the procedures in the "Setting up the environment" section.
  3
  Shows the mirror repository that contains the desired OpenShift Container Platform image. Get the mirrors from the imageContentSources.yaml file that you saved when following the procedures in the "Setting up the environment" section.
  4
  Shows the ClusterVersion CR to trigger the update. The channel, upstream, and desiredVersion fields are all required for image pre-caching.
  The PolicyGenTemplate CR generates two policies:
  - The du-upgrade-platform-upgrade-prep policy does the preparation work for the platform update. It creates the ConfigMap CR for the desired release image signature, creates the image content source of the mirrored release image repository, and updates the cluster version with the desired update channel and the update graph reachable by the managed cluster in the disconnected environment.
  - The du-upgrade-platform-upgrade policy is used to perform platform upgrade.
2. Add the du-upgrade.yaml file contents to the kustomization.yaml file located in the GitOps ZTP Git repository for the PolicyGenTemplate CRs and push the changes to the Git repository.
  ArgoCD pulls the changes from the Git repository and generates the policies on the hub cluster.
3. Check the created policies by running the following command:
```
$ oc get policies -A | grep platform-upgrade
```
Create the ClusterGroupUpdate CR for the platform update with the spec.enable field set to false.
1. Save the content of the platform update ClusterGroupUpdate CR with the du-upgrade-platform-upgrade-prep and the du-upgrade-platform-upgrade policies and the target clusters to the cgu-platform-upgrade.yml file, as shown in the following example:
```
apiVersion: ran.openshift.io/v1alpha1
kind: ClusterGroupUpgrade
metadata:
  name: cgu-platform-upgrade
  namespace: default
spec:
  managedPolicies:
  - du-upgrade-platform-upgrade-prep
  - du-upgrade-platform-upgrade
  preCaching: false
  clusters:
  - spoke1
  remediationStrategy:
    maxConcurrency: 1
  enable: false
```
2. Apply the ClusterGroupUpdate CR to the hub cluster by running the following command:
```
$ oc apply -f cgu-platform-upgrade.yml
```
Optional: Pre-cache the images for the platform update.
1. Enable pre-caching in the ClusterGroupUpdate CR by running the following command:
```
$ oc --namespace=default patch clustergroupupgrade.ran.openshift.io/cgu-platform-upgrade \
--patch '{"spec":{"preCaching": true}}' --type=merge
```
2. Monitor the update process and wait for the pre-caching to complete. Check the status of pre-caching by running the following command on the hub cluster:
```
$ oc get cgu cgu-platform-upgrade -o jsonpath='{.status.precaching.status}'
```
Start the platform update:
1. Enable the cgu-platform-upgrade policy and disable pre-caching by running the following command:
```
$ oc --namespace=default patch clustergroupupgrade.ran.openshift.io/cgu-platform-upgrade \
--patch '{"spec":{"enable":true, "preCaching": false}}' --type=merge
```
2. Monitor the process. Upon completion, ensure that the policy is compliant by running the following command:
```
$ oc get policies --all-namespaces
```

Additional resources

For more information about mirroring the images in a disconnected environment, see Preparing the disconnected environment.

18.12.1.3. Performing an Operator update

You can perform an Operator update with the TALM.

Prerequisites

Install the Topology Aware Lifecycle Manager (TALM).
Update GitOps Zero Touch Provisioning (ZTP) to the latest version.
Provision one or more managed clusters with GitOps ZTP.
Mirror the desired index image, bundle images, and all Operator images referenced in the bundle images.
Log in as a user with cluster-admin privileges.
Create RHACM policies in the hub cluster.

Procedure

Update the PolicyGenTemplate CR for the Operator update.
1. Update the du-upgrade PolicyGenTemplate CR with the following additional contents in the du-upgrade.yaml file:
```
apiVersion: ran.openshift.io/v1
kind: PolicyGenTemplate
metadata:
  name: "du-upgrade"
  namespace: "ztp-group-du-sno"
spec:
  bindingRules:
    group-du-sno: ""
  mcp: "master"
  remediationAction: inform
  sourceFiles:
    - fileName: DefaultCatsrc.yaml
      remediationAction: inform
      policyName: "operator-catsrc-policy"
      metadata:
        name: redhat-operators-disconnected
      spec:
        displayName: Red Hat Operators Catalog
        image: registry.example.com:5000/olm/redhat-operators-disconnected:v4.14 1
        updateStrategy: 2
          registryPoll:
            interval: 1h
      status:
        connectionState:
            lastObservedState: READY 3
```
  1
  The index image URL contains the desired Operator images. If the index images are always pushed to the same image name and tag, this change is not needed.
  2
  Set how frequently the Operator Lifecycle Manager (OLM) polls the index image for new Operator versions with the registryPoll.interval field. This change is not needed if a new index image tag is always pushed for y-stream and z-stream Operator updates. The registryPoll.interval field can be set to a shorter interval to expedite the update, however shorter intervals increase computational load. To counteract this, you can restore registryPoll.interval to the default value once the update is complete.
  3
  Last observed state of the catalog connection. The READY value ensures that the CatalogSource policy is ready, indicating that the index pod is pulled and is running. This way, TALM upgrades the Operators based on up-to-date policy compliance states.
2. This update generates one policy, du-upgrade-operator-catsrc-policy, to update the redhat-operators-disconnected catalog source with the new index images that contain the desired Operators images.
  Note
  If you want to use the image pre-caching for Operators and there are Operators from a different catalog source other than redhat-operators-disconnected, you must perform the following tasks:
  Prepare a separate catalog source policy with the new index image or registry poll interval update for the different catalog source.
  Prepare a separate subscription policy for the desired Operators that are from the different catalog source.
  For example, the desired SRIOV-FEC Operator is available in the certified-operators catalog source. To update the catalog source and the Operator subscription, add the following contents to generate two policies, du-upgrade-fec-catsrc-policy and du-upgrade-subscriptions-fec-policy:
```
apiVersion: ran.openshift.io/v1
kind: PolicyGenTemplate
metadata:
  name: "du-upgrade"
  namespace: "ztp-group-du-sno"
spec:
  bindingRules:
    group-du-sno: ""
  mcp: "master"
  remediationAction: inform
  sourceFiles:
       …
    - fileName: DefaultCatsrc.yaml
      remediationAction: inform
      policyName: "fec-catsrc-policy"
      metadata:
        name: certified-operators
      spec:
        displayName: Intel SRIOV-FEC Operator
        image: registry.example.com:5000/olm/far-edge-sriov-fec:v4.10
        updateStrategy:
          registryPoll:
            interval: 10m
    - fileName: AcceleratorsSubscription.yaml
      policyName: "subscriptions-fec-policy"
      spec:
        channel: "stable"
        source: certified-operators
```
3. Remove the specified subscriptions channels in the common PolicyGenTemplate CR, if they exist. The default subscriptions channels from the GitOps ZTP image are used for the update.
  Note
  The default channel for the Operators applied through GitOps ZTP 4.14 is stable, except for the performance-addon-operator. As of OpenShift Container Platform 4.11, the performance-addon-operator functionality was moved to the node-tuning-operator. For the 4.10 release, the default channel for PAO is v4.10. You can also specify the default channels in the common PolicyGenTemplate CR.
4. Push the PolicyGenTemplate CRs updates to the GitOps ZTP Git repository.
  ArgoCD pulls the changes from the Git repository and generates the policies on the hub cluster.
5. Check the created policies by running the following command:
```
$ oc get policies -A | grep -E "catsrc-policy|subscription"
```
Apply the required catalog source updates before starting the Operator update.
1. Save the content of the ClusterGroupUpgrade CR named operator-upgrade-prep with the catalog source policies and the target managed clusters to the cgu-operator-upgrade-prep.yml file:
```
apiVersion: ran.openshift.io/v1alpha1
kind: ClusterGroupUpgrade
metadata:
  name: cgu-operator-upgrade-prep
  namespace: default
spec:
  clusters:
  - spoke1
  enable: true
  managedPolicies:
  - du-upgrade-operator-catsrc-policy
  remediationStrategy:
    maxConcurrency: 1
```
2. Apply the policy to the hub cluster by running the following command:
```
$ oc apply -f cgu-operator-upgrade-prep.yml
```
3. Monitor the update process. Upon completion, ensure that the policy is compliant by running the following command:
```
$ oc get policies -A | grep -E "catsrc-policy"
```
Create the ClusterGroupUpgrade CR for the Operator update with the spec.enable field set to false.
1. Save the content of the Operator update ClusterGroupUpgrade CR with the du-upgrade-operator-catsrc-policy policy and the subscription policies created from the common PolicyGenTemplate and the target clusters to the cgu-operator-upgrade.yml file, as shown in the following example:
```
apiVersion: ran.openshift.io/v1alpha1
kind: ClusterGroupUpgrade
metadata:
  name: cgu-operator-upgrade
  namespace: default
spec:
  managedPolicies:
  - du-upgrade-operator-catsrc-policy 1
  - common-subscriptions-policy 2
  preCaching: false
  clusters:
  - spoke1
  remediationStrategy:
    maxConcurrency: 1
  enable: false
```
  1
  The policy is needed by the image pre-caching feature to retrieve the operator images from the catalog source.
  2
  The policy contains Operator subscriptions. If you have followed the structure and content of the reference PolicyGenTemplates, all Operator subscriptions are grouped into the common-subscriptions-policy policy.
  Note
  One ClusterGroupUpgrade CR can only pre-cache the images of the desired Operators defined in the subscription policy from one catalog source included in the ClusterGroupUpgrade CR. If the desired Operators are from different catalog sources, such as in the example of the SRIOV-FEC Operator, another ClusterGroupUpgrade CR must be created with du-upgrade-fec-catsrc-policy and du-upgrade-subscriptions-fec-policy policies for the SRIOV-FEC Operator images pre-caching and update.
2. Apply the ClusterGroupUpgrade CR to the hub cluster by running the following command:
```
$ oc apply -f cgu-operator-upgrade.yml
```

Optional: Pre-cache the images for the Operator update.

Before starting image pre-caching, verify the subscription policy is NonCompliant at this point by running the following command:

$ oc get policy common-subscriptions-policy -n <policy_namespace>

Example output

NAME                          REMEDIATION ACTION   COMPLIANCE STATE     AGE
common-subscriptions-policy   inform               NonCompliant         27d

Enable pre-caching in the ClusterGroupUpgrade CR by running the following command:

$ oc --namespace=default patch clustergroupupgrade.ran.openshift.io/cgu-operator-upgrade \
--patch '{"spec":{"preCaching": true}}' --type=merge

Monitor the process and wait for the pre-caching to complete. Check the status of pre-caching by running the following command on the managed cluster:
```
$ oc get cgu cgu-operator-upgrade -o jsonpath='{.status.precaching.status}'
```

Check if the pre-caching is completed before starting the update by running the following command:

$ oc get cgu -n default cgu-operator-upgrade -ojsonpath='{.status.conditions}' | jq

Example output

[
    {
      "lastTransitionTime": "2022-03-08T20:49:08.000Z",
      "message": "The ClusterGroupUpgrade CR is not enabled",
      "reason": "UpgradeNotStarted",
      "status": "False",
      "type": "Ready"
    },
    {
      "lastTransitionTime": "2022-03-08T20:55:30.000Z",
      "message": "Precaching is completed",
      "reason": "PrecachingCompleted",
      "status": "True",
      "type": "PrecachingDone"
    }
]

Start the Operator update.
1. Enable the cgu-operator-upgrade ClusterGroupUpgrade CR and disable pre-caching to start the Operator update by running the following command:
```
$ oc --namespace=default patch clustergroupupgrade.ran.openshift.io/cgu-operator-upgrade \
--patch '{"spec":{"enable":true, "preCaching": false}}' --type=merge
```
2. Monitor the process. Upon completion, ensure that the policy is compliant by running the following command:
```
$ oc get policies --all-namespaces
```

Additional resources

For more information about updating GitOps ZTP, see Upgrading GitOps ZTP.
Troubleshooting missed Operator updates due to out-of-date policy compliance states.

18.12.1.3.1. Troubleshooting missed Operator updates due to out-of-date policy compliance states

In some scenarios, Topology Aware Lifecycle Manager (TALM) might miss Operator updates due to an out-of-date policy compliance state.

After a catalog source update, it takes time for the Operator Lifecycle Manager (OLM) to update the subscription status. The status of the subscription policy might continue to show as compliant while TALM decides whether remediation is needed. As a result, the Operator specified in the subscription policy does not get upgraded.

To avoid this scenario, add another catalog source configuration to the PolicyGenTemplate and specify this configuration in the subscription for any Operators that require an update.

Procedure

Add a catalog source configuration in the PolicyGenTemplate resource:

- fileName: DefaultCatsrc.yaml
      remediationAction: inform
      policyName: "operator-catsrc-policy"
      metadata:
        name: redhat-operators-disconnected
      spec:
        displayName: Red Hat Operators Catalog
        image: registry.example.com:5000/olm/redhat-operators-disconnected:v{product-version}
        updateStrategy:
          registryPoll:
            interval: 1h
      status:
        connectionState:
            lastObservedState: READY
- fileName: DefaultCatsrc.yaml
      remediationAction: inform
      policyName: "operator-catsrc-policy"
      metadata:
        name: redhat-operators-disconnected-v2 1
      spec:
        displayName: Red Hat Operators Catalog v2 2
        image: registry.example.com:5000/olm/redhat-operators-disconnected:<version> 3
        updateStrategy:
          registryPoll:
            interval: 1h
      status:
        connectionState:
            lastObservedState: READY

1: Update the name for the new configuration.
2: Update the display name for the new configuration.
3: Update the index image URL. This fileName.spec.image field overrides any configuration in the DefaultCatsrc.yaml file.

Update the Subscription resource to point to the new configuration for Operators that require an update:
```
apiVersion: operators.coreos.com/v1alpha1
kind: Subscription
metadata:
  name: operator-subscription
  namespace: operator-namspace
# ...
spec:
  source: redhat-operators-disconnected-v2 1
# ...
```
1
Enter the name of the additional catalog source configuration that you defined in the PolicyGenTemplate resource.

18.12.1.4. Performing a platform and an Operator update together

You can perform a platform and an Operator update at the same time.

Prerequisites

Install the Topology Aware Lifecycle Manager (TALM).
Update GitOps Zero Touch Provisioning (ZTP) to the latest version.
Provision one or more managed clusters with GitOps ZTP.
Log in as a user with cluster-admin privileges.
Create RHACM policies in the hub cluster.

Procedure

Create the PolicyGenTemplate CR for the updates by following the steps described in the "Performing a platform update" and "Performing an Operator update" sections.
Apply the prep work for the platform and the Operator update.
1. Save the content of the ClusterGroupUpgrade CR with the policies for platform update preparation work, catalog source updates, and target clusters to the cgu-platform-operator-upgrade-prep.yml file, for example:
```
apiVersion: ran.openshift.io/v1alpha1
kind: ClusterGroupUpgrade
metadata:
  name: cgu-platform-operator-upgrade-prep
  namespace: default
spec:
  managedPolicies:
  - du-upgrade-platform-upgrade-prep
  - du-upgrade-operator-catsrc-policy
  clusterSelector:
  - group-du-sno
  remediationStrategy:
    maxConcurrency: 10
  enable: true
```
2. Apply the cgu-platform-operator-upgrade-prep.yml file to the hub cluster by running the following command:
```
$ oc apply -f cgu-platform-operator-upgrade-prep.yml
```
3. Monitor the process. Upon completion, ensure that the policy is compliant by running the following command:
```
$ oc get policies --all-namespaces
```
Create the ClusterGroupUpdate CR for the platform and the Operator update with the spec.enable field set to false.
1. Save the contents of the platform and Operator update ClusterGroupUpdate CR with the policies and the target clusters to the cgu-platform-operator-upgrade.yml file, as shown in the following example:
```
apiVersion: ran.openshift.io/v1alpha1
kind: ClusterGroupUpgrade
metadata:
  name: cgu-du-upgrade
  namespace: default
spec:
  managedPolicies:
  - du-upgrade-platform-upgrade 1
  - du-upgrade-operator-catsrc-policy 2
  - common-subscriptions-policy 3
  preCaching: true
  clusterSelector:
  - group-du-sno
  remediationStrategy:
    maxConcurrency: 1
  enable: false
```
  1
  This is the platform update policy.
  2
  This is the policy containing the catalog source information for the Operators to be updated. It is needed for the pre-caching feature to determine which Operator images to download to the managed cluster.
  3
  This is the policy to update the Operators.
2. Apply the cgu-platform-operator-upgrade.yml file to the hub cluster by running the following command:
```
$ oc apply -f cgu-platform-operator-upgrade.yml
```
Optional: Pre-cache the images for the platform and the Operator update.
1. Enable pre-caching in the ClusterGroupUpgrade CR by running the following command:
```
$ oc --namespace=default patch clustergroupupgrade.ran.openshift.io/cgu-du-upgrade \
--patch '{"spec":{"preCaching": true}}' --type=merge
```
2. Monitor the update process and wait for the pre-caching to complete. Check the status of pre-caching by running the following command on the managed cluster:
```
$ oc get jobs,pods -n openshift-talm-pre-cache
```
3. Check if the pre-caching is completed before starting the update by running the following command:
```
$ oc get cgu cgu-du-upgrade -ojsonpath='{.status.conditions}'
```
Start the platform and Operator update.
1. Enable the cgu-du-upgrade ClusterGroupUpgrade CR to start the platform and the Operator update by running the following command:
```
$ oc --namespace=default patch clustergroupupgrade.ran.openshift.io/cgu-du-upgrade \
--patch '{"spec":{"enable":true, "preCaching": false}}' --type=merge
```
2. Monitor the process. Upon completion, ensure that the policy is compliant by running the following command:
```
$ oc get policies --all-namespaces
```
  Note
  The CRs for the platform and Operator updates can be created from the beginning by configuring the setting to spec.enable: true. In this case, the update starts immediately after pre-caching completes and there is no need to manually enable the CR.
  Both pre-caching and the update create extra resources, such as policies, placement bindings, placement rules, managed cluster actions, and managed cluster view, to help complete the procedures. Setting the afterCompletion.deleteObjects field to true deletes all these resources after the updates complete.

18.12.1.5. Removing Performance Addon Operator subscriptions from deployed clusters

In earlier versions of OpenShift Container Platform, the Performance Addon Operator provided automatic, low latency performance tuning for applications. In OpenShift Container Platform 4.11 or later, these functions are part of the Node Tuning Operator.

Do not install the Performance Addon Operator on clusters running OpenShift Container Platform 4.11 or later. If you upgrade to OpenShift Container Platform 4.11 or later, the Node Tuning Operator automatically removes the Performance Addon Operator.

Note

You need to remove any policies that create Performance Addon Operator subscriptions to prevent a re-installation of the Operator.

The reference DU profile includes the Performance Addon Operator in the PolicyGenTemplate CR common-ranGen.yaml. To remove the subscription from deployed managed clusters, you must update common-ranGen.yaml.

Note

If you install Performance Addon Operator 4.10.3-5 or later on OpenShift Container Platform 4.11 or later, the Performance Addon Operator detects the cluster version and automatically hibernates to avoid interfering with the Node Tuning Operator functions. However, to ensure best performance, remove the Performance Addon Operator from your OpenShift Container Platform 4.11 clusters.

Prerequisites

Create a Git repository where you manage your custom site configuration data. The repository must be accessible from the hub cluster and be defined as a source repository for ArgoCD.
Update to OpenShift Container Platform 4.11 or later.
Log in as a user with cluster-admin privileges.

Procedure

Change the complianceType to mustnothave for the Performance Addon Operator namespace, Operator group, and subscription in the common-ranGen.yaml file.

 -  fileName: PaoSubscriptionNS.yaml
    policyName: "subscriptions-policy"
    complianceType: mustnothave
 -  fileName: PaoSubscriptionOperGroup.yaml
    policyName: "subscriptions-policy"
    complianceType: mustnothave
 -  fileName: PaoSubscription.yaml
    policyName: "subscriptions-policy"
    complianceType: mustnothave

Merge the changes with your custom site repository and wait for the ArgoCD application to synchronize the change to the hub cluster. The status of the common-subscriptions-policy policy changes to Non-Compliant.
Apply the change to your target clusters by using the Topology Aware Lifecycle Manager. For more information about rolling out configuration changes, see the "Additional resources" section.
Monitor the process. When the status of the common-subscriptions-policy policy for a target cluster is Compliant, the Performance Addon Operator has been removed from the cluster. Get the status of the common-subscriptions-policy by running the following command:
```
$ oc get policy -n ztp-common common-subscriptions-policy
```
Delete the Performance Addon Operator namespace, Operator group and subscription CRs from .spec.sourceFiles in the common-ranGen.yaml file.
Merge the changes with your custom site repository and wait for the ArgoCD application to synchronize the change to the hub cluster. The policy remains compliant.

18.12.1.6. Pre-caching user-specified images with TALM on single-node OpenShift clusters

You can pre-cache application-specific workload images on single-node OpenShift clusters before upgrading your applications.

You can specify the configuration options for the pre-caching jobs using the following custom resources (CR):

PreCachingConfig CR
ClusterGroupUpgrade CR

Note

All fields in the PreCachingConfig CR are optional.

Example PreCachingConfig CR

apiVersion: ran.openshift.io/v1alpha1
kind: PreCachingConfig
metadata:
  name: exampleconfig
  namespace: exampleconfig-ns
spec:
  overrides: 1
    platformImage: quay.io/openshift-release-dev/ocp-release@sha256:3d5800990dee7cd4727d3fe238a97e2d2976d3808fc925ada29c559a47e2e1ef
    operatorsIndexes:
      - registry.example.com:5000/custom-redhat-operators:1.0.0
    operatorsPackagesAndChannels:
      - local-storage-operator: stable
      - ptp-operator: stable
      - sriov-network-operator: stable
  spaceRequired: 30 Gi 2
  excludePrecachePatterns: 3
    - aws
    - vsphere
  additionalImages: 4
    - quay.io/exampleconfig/application1@sha256:3d5800990dee7cd4727d3fe238a97e2d2976d3808fc925ada29c559a47e2e1ef
    - quay.io/exampleconfig/application2@sha256:3d5800123dee7cd4727d3fe238a97e2d2976d3808fc925ada29c559a47adfaef
    - quay.io/exampleconfig/applicationN@sha256:4fe1334adfafadsf987123adfffdaf1243340adfafdedga0991234afdadfsa09

1: By default, TALM automatically populates the platformImage, operatorsIndexes, and the operatorsPackagesAndChannels fields from the policies of the managed clusters. You can specify values to override the default TALM-derived values for these fields.
2: Specifies the minimum required disk space on the cluster. If unspecified, TALM defines a default value for OpenShift Container Platform images. The disk space field must include an integer value and the storage unit. For example: 40 GiB, 200 MB, 1 TiB.
3: Specifies the images to exclude from pre-caching based on image name matching.
4: Specifies the list of additional images to pre-cache.

Example ClusterGroupUpgrade CR with PreCachingConfig CR reference

apiVersion: ran.openshift.io/v1alpha1
kind: ClusterGroupUpgrade
metadata:
  name: cgu
spec:
  preCaching: true 1
  preCachingConfigRef:
    name: exampleconfig 2
    namespace: exampleconfig-ns 3

1: The preCaching field set to true enables the pre-caching job.
2: The preCachingConfigRef.name field specifies the PreCachingConfig CR that you want to use.
3: The preCachingConfigRef.namespace specifies the namespace of the PreCachingConfig CR that you want to use.

18.12.1.6.1. Creating the custom resources for pre-caching

You must create the PreCachingConfig CR before or concurrently with the ClusterGroupUpgrade CR.

Create the PreCachingConfig CR with the list of additional images you want to pre-cache.

apiVersion: ran.openshift.io/v1alpha1
kind: PreCachingConfig
metadata:
  name: exampleconfig
  namespace: default 1
spec:
[...]
  spaceRequired: 30Gi 2
  additionalImages:
    - quay.io/exampleconfig/application1@sha256:3d5800990dee7cd4727d3fe238a97e2d2976d3808fc925ada29c559a47e2e1ef
    - quay.io/exampleconfig/application2@sha256:3d5800123dee7cd4727d3fe238a97e2d2976d3808fc925ada29c559a47adfaef
    - quay.io/exampleconfig/applicationN@sha256:4fe1334adfafadsf987123adfffdaf1243340adfafdedga0991234afdadfsa09

1: The namespace must be accessible to the hub cluster.
2: It is recommended to set the minimum disk space required field to ensure that there is sufficient storage space for the pre-cached images.

Create a ClusterGroupUpgrade CR with the preCaching field set to true and specify the PreCachingConfig CR created in the previous step:

apiVersion: ran.openshift.io/v1alpha1
kind: ClusterGroupUpgrade
metadata:
  name: cgu
  namespace: default
spec:
  clusters:
  - sno1
  - sno2
  preCaching: true
  preCachingConfigRef:
  - name: exampleconfig
    namespace: default
  managedPolicies:
    - du-upgrade-platform-upgrade
    - du-upgrade-operator-catsrc-policy
    - common-subscriptions-policy
  remediationStrategy:
    timeout: 240

Warning

Once you install the images on the cluster, you cannot change or delete them.

When you want to start pre-caching the images, apply the ClusterGroupUpgrade CR by running the following command:
```
$ oc apply -f cgu.yaml
```

TALM verifies the ClusterGroupUpgrade CR.

From this point, you can continue with the TALM pre-caching workflow.

Note

All sites are pre-cached concurrently.

Verification

Check the pre-caching status on the hub cluster where the ClusterUpgradeGroup CR is applied by running the following command:

$ oc get cgu <cgu_name> -n <cgu_namespace> -oyaml

Example output

  precaching:
    spec:
      platformImage: quay.io/openshift-release-dev/ocp-release@sha256:3d5800990dee7cd4727d3fe238a97e2d2976d3808fc925ada29c559a47e2e1ef
      operatorsIndexes:
        - registry.example.com:5000/custom-redhat-operators:1.0.0
      operatorsPackagesAndChannels:
        - local-storage-operator: stable
        - ptp-operator: stable
        - sriov-network-operator: stable
      excludePrecachePatterns:
        - aws
        - vsphere
      additionalImages:
        - quay.io/exampleconfig/application1@sha256:3d5800990dee7cd4727d3fe238a97e2d2976d3808fc925ada29c559a47e2e1ef
        - quay.io/exampleconfig/application2@sha256:3d5800123dee7cd4727d3fe238a97e2d2976d3808fc925ada29c559a47adfaef
        - quay.io/exampleconfig/applicationN@sha256:4fe1334adfafadsf987123adfffdaf1243340adfafdedga0991234afdadfsa09
      spaceRequired: "30"
    status:
      sno1: Starting
      sno2: Starting

The pre-caching configurations are validated by checking if the managed policies exist. Valid configurations of the ClusterGroupUpgrade and the PreCachingConfig CRs result in the following statuses:

Example output of valid CRs

- lastTransitionTime: "2023-01-01T00:00:01Z"
  message: All selected clusters are valid
  reason: ClusterSelectionCompleted
  status: "True"
  type: ClusterSelected
- lastTransitionTime: "2023-01-01T00:00:02Z"
  message: Completed validation
  reason: ValidationCompleted
  status: "True"
  type: Validated
- lastTransitionTime: "2023-01-01T00:00:03Z"
  message: Precaching spec is valid and consistent
  reason: PrecacheSpecIsWellFormed
  status: "True"
  type: PrecacheSpecValid
- lastTransitionTime: "2023-01-01T00:00:04Z"
  message: Precaching in progress for 1 clusters
  reason: InProgress
  status: "False"
  type: PrecachingSucceeded

Example of an invalid PreCachingConfig CR

Type:    "PrecacheSpecValid"
Status:  False,
Reason:  "PrecacheSpecIncomplete"
Message: "Precaching spec is incomplete: failed to get PreCachingConfig resource due to PreCachingConfig.ran.openshift.io "<pre-caching_cr_name>" not found"

You can find the pre-caching job by running the following command on the managed cluster:

$ oc get jobs -n openshift-talo-pre-cache

Example of pre-caching job in progress

NAME        COMPLETIONS       DURATION      AGE
pre-cache   0/1               1s            1s

You can check the status of the pod created for the pre-caching job by running the following command:

$ oc describe pod pre-cache -n openshift-talo-pre-cache

Example of pre-caching job in progress

Type        Reason              Age    From              Message
Normal      SuccesfulCreate     19s    job-controller    Created pod: pre-cache-abcd1

You can get live updates on the status of the job by running the following command:
```
$ oc logs -f pre-cache-abcd1 -n openshift-talo-pre-cache
```

To verify the pre-cache job is successfully completed, run the following command:

$ oc describe pod pre-cache -n openshift-talo-pre-cache

Example of completed pre-cache job

Type        Reason              Age    From              Message
Normal      SuccesfulCreate     5m19s  job-controller    Created pod: pre-cache-abcd1
Normal      Completed           19s    job-controller    Job completed

To verify that the images are successfully pre-cached on the single-node OpenShift, do the following:
1. Enter into the node in debug mode:
```
$ oc debug node/cnfdf00.example.lab
```
2. Change root to host:
```
$ chroot /host/
```
3. Search for the desired images:
```
$ sudo podman images | grep <operator_name>
```

Additional resources

For more information about the TALM pre-caching workflow, see Using the container image pre-cache feature.

18.12.2. About the auto-created ClusterGroupUpgrade CR for GitOps ZTP

TALM has a controller called ManagedClusterForCGU that monitors the Ready state of the ManagedCluster CRs on the hub cluster and creates the ClusterGroupUpgrade CRs for GitOps Zero Touch Provisioning (ZTP).

For any managed cluster in the Ready state without a ztp-done label applied, the ManagedClusterForCGU controller automatically creates a ClusterGroupUpgrade CR in the ztp-install namespace with its associated RHACM policies that are created during the GitOps ZTP process. TALM then remediates the set of configuration policies that are listed in the auto-created ClusterGroupUpgrade CR to push the configuration CRs to the managed cluster.

If there are no policies for the managed cluster at the time when the cluster becomes Ready, a ClusterGroupUpgrade CR with no policies is created. Upon completion of the ClusterGroupUpgrade the managed cluster is labeled as ztp-done. If there are policies that you want to apply for that managed cluster, manually create a ClusterGroupUpgrade as a day-2 operation.

Example of an auto-created ClusterGroupUpgrade CR for GitOps ZTP

apiVersion: ran.openshift.io/v1alpha1
kind: ClusterGroupUpgrade
metadata:
  generation: 1
  name: spoke1
  namespace: ztp-install
  ownerReferences:
  - apiVersion: cluster.open-cluster-management.io/v1
    blockOwnerDeletion: true
    controller: true
    kind: ManagedCluster
    name: spoke1
    uid: 98fdb9b2-51ee-4ee7-8f57-a84f7f35b9d5
  resourceVersion: "46666836"
  uid: b8be9cd2-764f-4a62-87d6-6b767852c7da
spec:
  actions:
    afterCompletion:
      addClusterLabels:
        ztp-done: "" 1
      deleteClusterLabels:
        ztp-running: ""
      deleteObjects: true
    beforeEnable:
      addClusterLabels:
        ztp-running: "" 2
  clusters:
  - spoke1
  enable: true
  managedPolicies:
  - common-spoke1-config-policy
  - common-spoke1-subscriptions-policy
  - group-spoke1-config-policy
  - spoke1-config-policy
  - group-spoke1-validator-du-policy
  preCaching: false
  remediationStrategy:
    maxConcurrency: 1
    timeout: 240

1: Applied to the managed cluster when TALM completes the cluster configuration.
2: Applied to the managed cluster when TALM starts deploying the configuration policies.

18.13. Expanding single-node OpenShift clusters with GitOps ZTP

You can expand single-node OpenShift clusters with GitOps Zero Touch Provisioning (ZTP). When you add worker nodes to single-node OpenShift clusters, the original single-node OpenShift cluster retains the control plane node role. Adding worker nodes does not require any downtime for the existing single-node OpenShift cluster.

Note

Although there is no specified limit on the number of worker nodes that you can add to a single-node OpenShift cluster, you must revaluate the reserved CPU allocation on the control plane node for the additional worker nodes.

If you require workload partitioning on the worker node, you must deploy and remediate the managed cluster policies on the hub cluster before installing the node. This way, the workload partitioning MachineConfig objects are rendered and associated with the worker machine config pool before the GitOps ZTP workflow applies the MachineConfig ignition file to the worker node.

It is recommended that you first remediate the policies, and then install the worker node. If you create the workload partitioning manifests after installing the worker node, you must drain the node manually and delete all the pods managed by daemon sets. When the managing daemon sets create the new pods, the new pods undergo the workload partitioning process.

Important

Adding worker nodes to single-node OpenShift clusters with GitOps ZTP is a Technology Preview feature only. Technology Preview features are not supported with Red Hat production service level agreements (SLAs) and might not be functionally complete. Red Hat does not recommend using them in production. These features provide early access to upcoming product features, enabling customers to test functionality and provide feedback during the development process.

For more information about the support scope of Red Hat Technology Preview features, see Technology Preview Features Support Scope.

Additional resources

For more information about single-node OpenShift clusters tuned for vDU application deployments, see Reference configuration for deploying vDUs on single-node OpenShift.
For more information about worker nodes, see Adding worker nodes to single-node OpenShift clusters.
For information about removing a worker node from an expanded single-node OpenShift cluster, see Removing managed cluster nodes by using the command line interface.

18.13.1. Applying profiles to the worker node

You can configure the additional worker node with a DU profile.

You can apply a RAN distributed unit (DU) profile to the worker node cluster using the GitOps Zero Touch Provisioning (ZTP) common, group, and site-specific PolicyGenTemplate resources. The GitOps ZTP pipeline that is linked to the ArgoCD policies application includes the following CRs that you can find in the out/argocd/example/policygentemplates folder when you extract the ztp-site-generate container:

common-ranGen.yaml
group-du-sno-ranGen.yaml
example-sno-site.yaml
ns.yaml
kustomization.yaml

Configuring the DU profile on the worker node is considered an upgrade. To initiate the upgrade flow, you must update the existing policies or create additional ones. Then, you must create a ClusterGroupUpgrade CR to reconcile the policies in the group of clusters.

18.13.2. (Optional) Ensuring PTP and SR-IOV daemon selector compatibility

If the DU profile was deployed using the GitOps Zero Touch Provisioning (ZTP) plugin version 4.11 or earlier, the PTP and SR-IOV Operators might be configured to place the daemons only on nodes labelled as master. This configuration prevents the PTP and SR-IOV daemons from operating on the worker node. If the PTP and SR-IOV daemon node selectors are incorrectly configured on your system, you must change the daemons before proceeding with the worker DU profile configuration.

Procedure

Check the daemon node selector settings of the PTP Operator on one of the spoke clusters:
```
$ oc get ptpoperatorconfig/default -n openshift-ptp -ojsonpath='{.spec}' | jq
```
Example output for PTP Operator
```
{"daemonNodeSelector":{"node-role.kubernetes.io/master":""}} 1
```
1
If the node selector is set to master, the spoke was deployed with the version of the GitOps ZTP plugin that requires changes.
Check the daemon node selector settings of the SR-IOV Operator on one of the spoke clusters:
```
$  oc get sriovoperatorconfig/default -n \
openshift-sriov-network-operator -ojsonpath='{.spec}' | jq
```
Example output for SR-IOV Operator
```
{"configDaemonNodeSelector":{"node-role.kubernetes.io/worker":""},"disableDrain":false,"enableInjector":true,"enableOperatorWebhook":true} 1
```
1
If the node selector is set to master, the spoke was deployed with the version of the GitOps ZTP plugin that requires changes.

In the group policy, add the following complianceType and spec entries:

spec:
    - fileName: PtpOperatorConfig.yaml
      policyName: "config-policy"
      complianceType: mustonlyhave
      spec:
        daemonNodeSelector:
          node-role.kubernetes.io/worker: ""
    - fileName: SriovOperatorConfig.yaml
      policyName: "config-policy"
      complianceType: mustonlyhave
      spec:
        configDaemonNodeSelector:
          node-role.kubernetes.io/worker: ""

Important

Changing the daemonNodeSelector field causes temporary PTP synchronization loss and SR-IOV connectivity loss.

Commit the changes in Git, and then push to the Git repository being monitored by the GitOps ZTP ArgoCD application.

18.13.3. PTP and SR-IOV node selector compatibility

The PTP configuration resources and SR-IOV network node policies use node-role.kubernetes.io/master: "" as the node selector. If the additional worker nodes have the same NIC configuration as the control plane node, the policies used to configure the control plane node can be reused for the worker nodes. However, the node selector must be changed to select both node types, for example with the "node-role.kubernetes.io/worker" label.

18.13.4. Using PolicyGenTemplate CRs to apply worker node policies to worker nodes

You can create policies for worker nodes.

Procedure

Create the following policy template:

apiVersion: ran.openshift.io/v1
kind: PolicyGenTemplate
metadata:
  name: "example-sno-workers"
  namespace: "example-sno"
spec:
  bindingRules:
    sites: "example-sno" 1
  mcp: "worker" 2
  sourceFiles:
    - fileName: MachineConfigGeneric.yaml 3
      policyName: "config-policy"
      metadata:
        labels:
          machineconfiguration.openshift.io/role: worker
        name: enable-workload-partitioning
      spec:
        config:
          storage:
            files:
            - contents:
                source: data:text/plain;charset=utf-8;base64,W2NyaW8ucnVudGltZS53b3JrbG9hZHMubWFuYWdlbWVudF0KYWN0aXZhdGlvbl9hbm5vdGF0aW9uID0gInRhcmdldC53b3JrbG9hZC5vcGVuc2hpZnQuaW8vbWFuYWdlbWVudCIKYW5ub3RhdGlvbl9wcmVmaXggPSAicmVzb3VyY2VzLndvcmtsb2FkLm9wZW5zaGlmdC5pbyIKcmVzb3VyY2VzID0geyAiY3B1c2hhcmVzIiA9IDAsICJjcHVzZXQiID0gIjAtMyIgfQo=
              mode: 420
              overwrite: true
              path: /etc/crio/crio.conf.d/01-workload-partitioning
              user:
                name: root
            - contents:
                source: data:text/plain;charset=utf-8;base64,ewogICJtYW5hZ2VtZW50IjogewogICAgImNwdXNldCI6ICIwLTMiCiAgfQp9Cg==
              mode: 420
              overwrite: true
              path: /etc/kubernetes/openshift-workload-pinning
              user:
                name: root
    - fileName: PerformanceProfile.yaml
      policyName: "config-policy"
      metadata:
        name: openshift-worker-node-performance-profile
      spec:
        cpu: 4
          isolated: "4-47"
          reserved: "0-3"
        hugepages:
          defaultHugepagesSize: 1G
          pages:
            - size: 1G
              count: 32
        realTimeKernel:
          enabled: true
    - fileName: TunedPerformancePatch.yaml
      policyName: "config-policy"
      metadata:
        name: performance-patch-worker
      spec:
        profile:
          - name: performance-patch-worker
            data: |
              [main]
              summary=Configuration changes profile inherited from performance created tuned
              include=openshift-node-performance-openshift-worker-node-performance-profile
              [bootloader]
              cmdline_crash=nohz_full=4-47 5
              [sysctl]
              kernel.timer_migration=1
              [scheduler]
              group.ice-ptp=0:f:10:*:ice-ptp.*
              [service]
              service.stalld=start,enable
              service.chronyd=stop,disable
        recommend:
        - profile: performance-patch-worker

1: The policies are applied to all clusters with this label.
2: The MCP field must be set to worker.
3: This generic MachineConfig CR is used to configure workload partitioning on the worker node.
4: The cpu.isolated and cpu.reserved fields must be configured for each particular hardware platform.
5: The cmdline_crash CPU set must match the cpu.isolated set in the PerformanceProfile section.

A generic MachineConfig CR is used to configure workload partitioning on the worker node. You can generate the content of crio and kubelet configuration files.

Add the created policy template to the Git repository monitored by the ArgoCD policies application.
Add the policy in the kustomization.yaml file.
Commit the changes in Git, and then push to the Git repository being monitored by the GitOps ZTP ArgoCD application.

To remediate the new policies to your spoke cluster, create a TALM custom resource:

$ cat <<EOF | oc apply -f -
apiVersion: ran.openshift.io/v1alpha1
kind: ClusterGroupUpgrade
metadata:
  name: example-sno-worker-policies
  namespace: default
spec:
  backup: false
  clusters:
  - example-sno
  enable: true
  managedPolicies:
  - group-du-sno-config-policy
  - example-sno-workers-config-policy
  - example-sno-config-policy
  preCaching: false
  remediationStrategy:
    maxConcurrency: 1
EOF

18.13.5. Adding worker nodes to single-node OpenShift clusters with GitOps ZTP

You can add one or more worker nodes to existing single-node OpenShift clusters to increase available CPU resources in the cluster.

Prerequisites

Install and configure RHACM 2.6 or later in an OpenShift Container Platform 4.11 or later bare-metal hub cluster
Install Topology Aware Lifecycle Manager in the hub cluster
Install Red Hat OpenShift GitOps in the hub cluster
Use the GitOps ZTP ztp-site-generate container image version 4.12 or later
Deploy a managed single-node OpenShift cluster with GitOps ZTP
Configure the Central Infrastructure Management as described in the RHACM documentation
Configure the DNS serving the cluster to resolve the internal API endpoint api-int.<cluster_name>.<base_domain>

Procedure

If you deployed your cluster by using the example-sno.yaml SiteConfig manifest, add your new worker node to the spec.clusters['example-sno'].nodes list:

nodes:
- hostName: "example-node2.example.com"
  role: "worker"
  bmcAddress: "idrac-virtualmedia+https://[1111:2222:3333:4444::bbbb:1]/redfish/v1/Systems/System.Embedded.1"
  bmcCredentialsName:
    name: "example-node2-bmh-secret"
  bootMACAddress: "AA:BB:CC:DD:EE:11"
  bootMode: "UEFI"
  nodeNetwork:
    interfaces:
      - name: eno1
        macAddress: "AA:BB:CC:DD:EE:11"
    config:
      interfaces:
        - name: eno1
          type: ethernet
          state: up
          macAddress: "AA:BB:CC:DD:EE:11"
          ipv4:
            enabled: false
          ipv6:
            enabled: true
            address:
            - ip: 1111:2222:3333:4444::1
              prefix-length: 64
      dns-resolver:
        config:
          search:
          - example.com
          server:
          - 1111:2222:3333:4444::2
      routes:
        config:
        - destination: ::/0
          next-hop-interface: eno1
          next-hop-address: 1111:2222:3333:4444::1
          table-id: 254

Create a BMC authentication secret for the new host, as referenced by the bmcCredentialsName field in the spec.nodes section of your SiteConfig file:

apiVersion: v1
data:
  password: "password"
  username: "username"
kind: Secret
metadata:
  name: "example-node2-bmh-secret"
  namespace: example-sno
type: Opaque

Commit the changes in Git, and then push to the Git repository that is being monitored by the GitOps ZTP ArgoCD application.
When the ArgoCD cluster application synchronizes, two new manifests appear on the hub cluster generated by the GitOps ZTP plugin:
- BareMetalHost
- NMStateConfig
  Important
  The cpuset field should not be configured for the worker node. Workload partitioning for worker nodes is added through management policies after the node installation is complete.

Verification

You can monitor the installation process in several ways.

Check if the preprovisioning images are created by running the following command:

$ oc get ppimg -n example-sno

Example output

NAMESPACE       NAME            READY   REASON
example-sno     example-sno     True    ImageCreated
example-sno     example-node2   True    ImageCreated

Check the state of the bare-metal hosts:

$ oc get bmh -n example-sno

Example output

NAME            STATE          CONSUMER   ONLINE   ERROR   AGE
example-sno     provisioned               true             69m
example-node2   provisioning              true             4m50s 1

1: The provisioning state indicates that node booting from the installation media is in progress.

Continuously monitor the installation process:

Watch the agent install process by running the following command:

$ oc get agent -n example-sno --watch

Example output

NAME                                   CLUSTER   APPROVED   ROLE     STAGE
671bc05d-5358-8940-ec12-d9ad22804faa   example-sno   true       master   Done
[...]
14fd821b-a35d-9cba-7978-00ddf535ff37   example-sno   true       worker   Starting installation
14fd821b-a35d-9cba-7978-00ddf535ff37   example-sno   true       worker   Installing
14fd821b-a35d-9cba-7978-00ddf535ff37   example-sno   true       worker   Writing image to disk
[...]
14fd821b-a35d-9cba-7978-00ddf535ff37   example-sno   true       worker   Waiting for control plane
[...]
14fd821b-a35d-9cba-7978-00ddf535ff37   example-sno   true       worker   Rebooting
14fd821b-a35d-9cba-7978-00ddf535ff37   example-sno   true       worker   Done

When the worker node installation is finished, the worker node certificates are approved automatically. At this point, the worker appears in the ManagedClusterInfo status. Run the following command to see the status:

$ oc get managedclusterinfo/example-sno -n example-sno -o \
jsonpath='{range .status.nodeList[*]}{.name}{"\t"}{.conditions}{"\t"}{.labels}{"\n"}{end}'

Example output

example-sno	[{"status":"True","type":"Ready"}]	{"node-role.kubernetes.io/master":"","node-role.kubernetes.io/worker":""}
example-node2	[{"status":"True","type":"Ready"}]	{"node-role.kubernetes.io/worker":""}

18.14. Pre-caching images for single-node OpenShift deployments

In environments with limited bandwidth where you use the GitOps Zero Touch Provisioning (ZTP) solution to deploy a large number of clusters, you want to avoid downloading all the images that are required for bootstrapping and installing OpenShift Container Platform. The limited bandwidth at remote single-node OpenShift sites can cause long deployment times. The factory-precaching-cli tool allows you to pre-stage servers before shipping them to the remote site for ZTP provisioning.

The factory-precaching-cli tool does the following:

Downloads the RHCOS rootfs image that is required by the minimal ISO to boot.
Creates a partition from the installation disk labelled as data.
Formats the disk in xfs.
Creates a GUID Partition Table (GPT) data partition at the end of the disk, where the size of the partition is configurable by the tool.
Copies the container images required to install OpenShift Container Platform.
Copies the container images required by ZTP to install OpenShift Container Platform.
Optional: Copies Day-2 Operators to the partition.

Important

The factory-precaching-cli tool is a Technology Preview feature only. Technology Preview features are not supported with Red Hat production service level agreements (SLAs) and might not be functionally complete. Red Hat does not recommend using them in production. These features provide early access to upcoming product features, enabling customers to test functionality and provide feedback during the development process.

For more information about the support scope of Red Hat Technology Preview features, see Technology Preview Features Support Scope.

18.14.1. Getting the factory-precaching-cli tool

The factory-precaching-cli tool Go binary is publicly available in the Telco RAN distributed unit (DU) tools container image. The factory-precaching-cli tool Go binary in the container image is executed on the server running an RHCOS live image using podman. If you are working in a disconnected environment or have a private registry, you need to copy the image there so you can download the image to the server.

Procedure

Pull the factory-precaching-cli tool image by running the following command:
```
# podman pull quay.io/openshift-kni/telco-ran-tools:latest
```

Verification

To check that the tool is available, query the current version of the factory-precaching-cli tool Go binary:

# podman run quay.io/openshift-kni/telco-ran-tools:latest -- factory-precaching-cli -v

Example output

factory-precaching-cli version 20221018.120852+main.feecf17

18.14.2. Booting from a live operating system image

You can use the factory-precaching-cli tool with to boot servers where only one disk is available and external disk drive cannot be attached to the server.

Warning

RHCOS requires the disk to not be in use when the disk is about to be written with an RHCOS image.

Depending on the server hardware, you can mount the RHCOS live ISO on the blank server using one of the following methods:

Using the Dell RACADM tool on a Dell server.
Using the HPONCFG tool on a HP server.
Using the Redfish BMC API.

Note

It is recommended to automate the mounting procedure. To automate the procedure, you need to pull the required images and host them on a local HTTP server.

Prerequisites

You powered up the host.
You have network connectivity to the host.

Procedure

This example procedure uses the Redfish BMC API to mount the RHCOS live ISO.

Mount the RHCOS live ISO:

Check virtual media status:

$ curl --globoff -H "Content-Type: application/json" -H \
"Accept: application/json" -k -X GET --user ${username_password} \
https://$BMC_ADDRESS/redfish/v1/Managers/Self/VirtualMedia/1 | python -m json.tool

Mount the ISO file as a virtual media:

$ curl --globoff -L -w "%{http_code} %{url_effective}\\n" -ku ${username_password} -H "Content-Type: application/json" -H "Accept: application/json" -d '{"Image": "http://[$HTTPd_IP]/RHCOS-live.iso"}' -X POST https://$BMC_ADDRESS/redfish/v1/Managers/Self/VirtualMedia/1/Actions/VirtualMedia.InsertMedia

Set the boot order to boot from the virtual media once:

$ curl --globoff  -L -w "%{http_code} %{url_effective}\\n"  -ku ${username_password}  -H "Content-Type: application/json" -H "Accept: application/json" -d '{"Boot":{ "BootSourceOverrideEnabled": "Once", "BootSourceOverrideTarget": "Cd", "BootSourceOverrideMode": "UEFI"}}' -X PATCH https://$BMC_ADDRESS/redfish/v1/Systems/Self

Reboot and ensure that the server is booting from virtual media.

Additional resources

For more information about the butane utility, see About Butane.
For more information about creating a custom live RHCOS ISO, see Creating a custom live RHCOS ISO for remote server access.
For more information about using the Dell RACADM tool, see Integrated Dell Remote Access Controller 9 RACADM CLI Guide.
For more information about using the HP HPONCFG tool, see Using HPONCFG.
For more information about using the Redfish BMC API, see Booting from an HTTP-hosted ISO image using the Redfish API.

18.14.3. Partitioning the disk

To run the full pre-caching process, you have to boot from a live ISO and use the factory-precaching-cli tool from a container image to partition and pre-cache all the artifacts required.

A live ISO or RHCOS live ISO is required because the disk must not be in use when the operating system (RHCOS) is written to the device during the provisioning. Single-disk servers can also be enabled with this procedure.

Prerequisites

You have a disk that is not partitioned.
You have access to the quay.io/openshift-kni/telco-ran-tools:latest image.
You have enough storage to install OpenShift Container Platform and pre-cache the required images.

Procedure

Verify that the disk is cleared:

# lsblk

Example output

NAME    MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
loop0     7:0    0  93.8G  0 loop /run/ephemeral
loop1     7:1    0 897.3M  1 loop /sysroot
sr0      11:0    1   999M  0 rom  /run/media/iso
nvme0n1 259:1    0   1.5T  0 disk

Erase any file system, RAID or partition table signatures from the device:

# wipefs -a /dev/nvme0n1

Example output

/dev/nvme0n1: 8 bytes were erased at offset 0x00000200 (gpt): 45 46 49 20 50 41 52 54
/dev/nvme0n1: 8 bytes were erased at offset 0x1749a955e00 (gpt): 45 46 49 20 50 41 52 54
/dev/nvme0n1: 2 bytes were erased at offset 0x000001fe (PMBR): 55 aa

Important

The tool fails if the disk is not empty because it uses partition number 1 of the device for pre-caching the artifacts.

18.14.3.1. Creating the partition

Once the device is ready, you create a single partition and a GPT partition table. The partition is automatically labelled as data and created at the end of the device. Otherwise, the partition will be overridden by the coreos-installer.

Important

The coreos-installer requires the partition to be created at the end of the device and to be labelled as data. Both requirements are necessary to save the partition when writing the RHCOS image to the disk.

Prerequisites

The container must run as privileged due to formatting host devices.
You have to mount the /dev folder so that the process can be executed inside the container.

Procedure

In the following example, the size of the partition is 250 GiB due to allow pre-caching the DU profile for Day 2 Operators.

Run the container as privileged and partition the disk:
```
# podman run -v /dev:/dev --privileged \
--rm quay.io/openshift-kni/telco-ran-tools:latest -- \
factory-precaching-cli partition \ 1
-d /dev/nvme0n1 \ 2
-s 250 3
```
1
Specifies the partitioning function of the factory-precaching-cli tool.
2
Defines the root directory on the disk.
3
Defines the size of the disk in GB.

Check the storage information:

# lsblk

Example output

NAME        MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
loop0         7:0    0  93.8G  0 loop /run/ephemeral
loop1         7:1    0 897.3M  1 loop /sysroot
sr0          11:0    1   999M  0 rom  /run/media/iso
nvme0n1     259:1    0   1.5T  0 disk
└─nvme0n1p1 259:3    0   250G  0 part

Verification

You must verify that the following requirements are met:

The device has a GPT partition table
The partition uses the latest sectors of the device.
The partition is correctly labeled as data.

Query the disk status to verify that the disk is partitioned as expected:

# gdisk -l /dev/nvme0n1

Example output

GPT fdisk (gdisk) version 1.0.3

Partition table scan:
  MBR: protective
  BSD: not present
  APM: not present
  GPT: present

Found valid GPT with protective MBR; using GPT.
Disk /dev/nvme0n1: 3125627568 sectors, 1.5 TiB
Model: Dell Express Flash PM1725b 1.6TB SFF
Sector size (logical/physical): 512/512 bytes
Disk identifier (GUID): CB5A9D44-9B3C-4174-A5C1-C64957910B61
Partition table holds up to 128 entries
Main partition table begins at sector 2 and ends at sector 33
First usable sector is 34, last usable sector is 3125627534
Partitions will be aligned on 2048-sector boundaries
Total free space is 2601338846 sectors (1.2 TiB)

Number  Start (sector)    End (sector)  Size       Code  Name
   1      2601338880      3125627534   250.0 GiB   8300  data

18.14.3.2. Mounting the partition

After verifying that the disk is partitioned correctly, you can mount the device into /mnt.

Important

It is recommended to mount the device into /mnt because that mounting point is used during GitOps ZTP preparation.

Verify that the partition is formatted as xfs:

# lsblk -f /dev/nvme0n1

Example output

NAME        FSTYPE LABEL UUID                                 MOUNTPOINT
nvme0n1
└─nvme0n1p1 xfs          1bee8ea4-d6cf-4339-b690-a76594794071

Mount the partition:
```
# mount /dev/nvme0n1p1 /mnt/
```

Verification

Check that the partition is mounted:

# lsblk

Example output

NAME        MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
loop0         7:0    0  93.8G  0 loop /run/ephemeral
loop1         7:1    0 897.3M  1 loop /sysroot
sr0          11:0    1   999M  0 rom  /run/media/iso
nvme0n1     259:1    0   1.5T  0 disk
└─nvme0n1p1 259:2    0   250G  0 part /var/mnt 1

1: The mount point is /var/mnt because the /mnt folder in RHCOS is a link to /var/mnt.

18.14.4. Downloading the images

The factory-precaching-cli tool allows you to download the following images to your partitioned server:

OpenShift Container Platform images
Operator images that are included in the distributed unit (DU) profile for 5G RAN sites
Operator images from disconnected registries

Note

The list of available Operator images can vary in different OpenShift Container Platform releases.

18.14.4.1. Downloading with parallel workers

The factory-precaching-cli tool uses parallel workers to download multiple images simultaneously. You can configure the number of workers with the --parallel or -p option. The default number is set to 80% of the available CPUs to the server.

Note

Your login shell may be restricted to a subset of CPUs, which reduces the CPUs available to the container. To remove this restriction, you can precede your commands with taskset 0xffffffff, for example:

# taskset 0xffffffff podman run --rm quay.io/openshift-kni/telco-ran-tools:latest factory-precaching-cli download --help

18.14.4.2. Preparing to download the OpenShift Container Platform images

To download OpenShift Container Platform container images, you need to know the multicluster engine version. When you use the --du-profile flag, you also need to specify the Red Hat Advanced Cluster Management (RHACM) version running in the hub cluster that is going to provision the single-node OpenShift.

Prerequisites

You have RHACM and the multicluster engine Operator installed.
You partitioned the storage device.
You have enough space for the images on the partitioned device.
You connected the bare-metal server to the Internet.
You have a valid pull secret.

Procedure

Check the RHACM version and the multicluster engine version by running the following commands in the hub cluster:

$ oc get csv -A | grep -i advanced-cluster-management

Example output

open-cluster-management                            advanced-cluster-management.v2.6.3           Advanced Cluster Management for Kubernetes   2.6.3                 advanced-cluster-management.v2.6.3                Succeeded

$ oc get csv -A | grep -i multicluster-engine

Example output

multicluster-engine                                cluster-group-upgrades-operator.v0.0.3       cluster-group-upgrades-operator              0.0.3                                                                   Pending
multicluster-engine                                multicluster-engine.v2.1.4                   multicluster engine for Kubernetes           2.1.4                 multicluster-engine.v2.0.3                        Succeeded
multicluster-engine                                openshift-gitops-operator.v1.5.7             Red Hat OpenShift GitOps                     1.5.7                 openshift-gitops-operator.v1.5.6-0.1664915551.p   Succeeded
multicluster-engine                                openshift-pipelines-operator-rh.v1.6.4       Red Hat OpenShift Pipelines                  1.6.4                 openshift-pipelines-operator-rh.v1.6.3            Succeeded

To access the container registry, copy a valid pull secret on the server to be installed:
1. Create the .docker folder:
```
$ mkdir /root/.docker
```
2. Copy the valid pull in the config.json file to the previously created .docker/ folder:
```
$ cp config.json /root/.docker/config.json 1
```
  1
  /root/.docker/config.json is the default path where podman checks for the login credentials for the registry.

Note

If you use a different registry to pull the required artifacts, you need to copy the proper pull secret. If the local registry uses TLS, you need to include the certificates from the registry as well.

18.14.4.3. Downloading the OpenShift Container Platform images

The factory-precaching-cli tool allows you to pre-cache all the container images required to provision a specific OpenShift Container Platform release.

Procedure

Pre-cache the release by running the following command:

# podman run -v /mnt:/mnt -v /root/.docker:/root/.docker --privileged --rm quay.io/openshift-kni/telco-ran-tools -- \
   factory-precaching-cli download \ 1
   -r 4.14.0 \ 2
   --acm-version 2.6.3 \ 3
   --mce-version 2.1.4 \ 4
   -f /mnt \ 5
   --img quay.io/custom/repository 6

1: Specifies the downloading function of the factory-precaching-cli tool.
2: Defines the OpenShift Container Platform release version.
3: Defines the RHACM version.
4: Defines the multicluster engine version.
5: Defines the folder where you want to download the images on the disk.
6: Optional. Defines the repository where you store your additional images. These images are downloaded and pre-cached on the disk.

Example output

Generated /mnt/imageset.yaml
Generating list of pre-cached artifacts...
Processing artifact [1/176]: ocp-v4.0-art-dev@sha256_6ac2b96bf4899c01a87366fd0feae9f57b1b61878e3b5823da0c3f34f707fbf5
Processing artifact [2/176]: ocp-v4.0-art-dev@sha256_f48b68d5960ba903a0d018a10544ae08db5802e21c2fa5615a14fc58b1c1657c
Processing artifact [3/176]: ocp-v4.0-art-dev@sha256_a480390e91b1c07e10091c3da2257180654f6b2a735a4ad4c3b69dbdb77bbc06
Processing artifact [4/176]: ocp-v4.0-art-dev@sha256_ecc5d8dbd77e326dba6594ff8c2d091eefbc4d90c963a9a85b0b2f0e6155f995
Processing artifact [5/176]: ocp-v4.0-art-dev@sha256_274b6d561558a2f54db08ea96df9892315bb773fc203b1dbcea418d20f4c7ad1
Processing artifact [6/176]: ocp-v4.0-art-dev@sha256_e142bf5020f5ca0d1bdda0026bf97f89b72d21a97c9cc2dc71bf85050e822bbf
...
Processing artifact [175/176]: ocp-v4.0-art-dev@sha256_16cd7eda26f0fb0fc965a589e1e96ff8577e560fcd14f06b5fda1643036ed6c8
Processing artifact [176/176]: ocp-v4.0-art-dev@sha256_cf4d862b4a4170d4f611b39d06c31c97658e309724f9788e155999ae51e7188f
...
Summary:

Release:                            4.14.0
Hub Version:                        2.6.3
ACM Version:                        2.6.3
MCE Version:                        2.1.4
Include DU Profile:                 No
Workers:                            83

Verification

Check that all the images are compressed in the target folder of server:

$ ls -l /mnt 1

1: It is recommended that you pre-cache the images in the /mnt folder.

Example output

-rw-r--r--. 1 root root  136352323 Oct 31 15:19 ocp-v4.0-art-dev@sha256_edec37e7cd8b1611d0031d45e7958361c65e2005f145b471a8108f1b54316c07.tgz
-rw-r--r--. 1 root root  156092894 Oct 31 15:33 ocp-v4.0-art-dev@sha256_ee51b062b9c3c9f4fe77bd5b3cc9a3b12355d040119a1434425a824f137c61a9.tgz
-rw-r--r--. 1 root root  172297800 Oct 31 15:29 ocp-v4.0-art-dev@sha256_ef23d9057c367a36e4a5c4877d23ee097a731e1186ed28a26c8d21501cd82718.tgz
-rw-r--r--. 1 root root  171539614 Oct 31 15:23 ocp-v4.0-art-dev@sha256_f0497bb63ef6834a619d4208be9da459510df697596b891c0c633da144dbb025.tgz
-rw-r--r--. 1 root root  160399150 Oct 31 15:20 ocp-v4.0-art-dev@sha256_f0c339da117cde44c9aae8d0bd054bceb6f19fdb191928f6912a703182330ac2.tgz
-rw-r--r--. 1 root root  175962005 Oct 31 15:17 ocp-v4.0-art-dev@sha256_f19dd2e80fb41ef31d62bb8c08b339c50d193fdb10fc39cc15b353cbbfeb9b24.tgz
-rw-r--r--. 1 root root  174942008 Oct 31 15:33 ocp-v4.0-art-dev@sha256_f1dbb81fa1aa724e96dd2b296b855ff52a565fbef003d08030d63590ae6454df.tgz
-rw-r--r--. 1 root root  246693315 Oct 31 15:31 ocp-v4.0-art-dev@sha256_f44dcf2c94e4fd843cbbf9b11128df2ba856cd813786e42e3da1fdfb0f6ddd01.tgz
-rw-r--r--. 1 root root  170148293 Oct 31 15:00 ocp-v4.0-art-dev@sha256_f48b68d5960ba903a0d018a10544ae08db5802e21c2fa5615a14fc58b1c1657c.tgz
-rw-r--r--. 1 root root  168899617 Oct 31 15:16 ocp-v4.0-art-dev@sha256_f5099b0989120a8d08a963601214b5c5cb23417a707a8624b7eb52ab788a7f75.tgz
-rw-r--r--. 1 root root  176592362 Oct 31 15:05 ocp-v4.0-art-dev@sha256_f68c0e6f5e17b0b0f7ab2d4c39559ea89f900751e64b97cb42311a478338d9c3.tgz
-rw-r--r--. 1 root root  157937478 Oct 31 15:37 ocp-v4.0-art-dev@sha256_f7ba33a6a9db9cfc4b0ab0f368569e19b9fa08f4c01a0d5f6a243d61ab781bd8.tgz
-rw-r--r--. 1 root root  145535253 Oct 31 15:26 ocp-v4.0-art-dev@sha256_f8f098911d670287826e9499806553f7a1dd3e2b5332abbec740008c36e84de5.tgz
-rw-r--r--. 1 root root  158048761 Oct 31 15:40 ocp-v4.0-art-dev@sha256_f914228ddbb99120986262168a705903a9f49724ffa958bb4bf12b2ec1d7fb47.tgz
-rw-r--r--. 1 root root  167914526 Oct 31 15:37 ocp-v4.0-art-dev@sha256_fa3ca9401c7a9efda0502240aeb8d3ae2d239d38890454f17fe5158b62305010.tgz
-rw-r--r--. 1 root root  164432422 Oct 31 15:24 ocp-v4.0-art-dev@sha256_fc4783b446c70df30b3120685254b40ce13ba6a2b0bf8fb1645f116cf6a392f1.tgz
-rw-r--r--. 1 root root  306643814 Oct 31 15:11 troubleshoot@sha256_b86b8aea29a818a9c22944fd18243fa0347c7a2bf1ad8864113ff2bb2d8e0726.tgz

18.14.4.4. Downloading the Operator images

You can also pre-cache Day-2 Operators used in the 5G Radio Access Network (RAN) Distributed Unit (DU) cluster configuration. The Day-2 Operators depend on the installed OpenShift Container Platform version.

Important

You need to include the RHACM hub and multicluster engine Operator versions by using the --acm-version and --mce-version flags so the factory-precaching-cli tool can pre-cache the appropriate containers images for RHACM and the multicluster engine Operator.

Procedure

Pre-cache the Operator images:

# podman run -v /mnt:/mnt -v /root/.docker:/root/.docker --privileged --rm quay.io/openshift-kni/telco-ran-tools:latest -- factory-precaching-cli download \ 1
   -r 4.14.0 \ 2
   --acm-version 2.6.3 \ 3
   --mce-version 2.1.4 \ 4
   -f /mnt \ 5
   --img quay.io/custom/repository 6
   --du-profile -s 7

1: Specifies the downloading function of the factory-precaching-cli tool.
2: Defines the OpenShift Container Platform release version.
3: Defines the RHACM version.
4: Defines the multicluster engine version.
5: Defines the folder where you want to download the images on the disk.
6: Optional. Defines the repository where you store your additional images. These images are downloaded and pre-cached on the disk.
7: Specifies pre-caching the Operators included in the DU configuration.

Example output

Generated /mnt/imageset.yaml
Generating list of pre-cached artifacts...
Processing artifact [1/379]: ocp-v4.0-art-dev@sha256_7753a8d9dd5974be8c90649aadd7c914a3d8a1f1e016774c7ac7c9422e9f9958
Processing artifact [2/379]: ose-kube-rbac-proxy@sha256_c27a7c01e5968aff16b6bb6670423f992d1a1de1a16e7e260d12908d3322431c
Processing artifact [3/379]: ocp-v4.0-art-dev@sha256_370e47a14c798ca3f8707a38b28cfc28114f492bb35fe1112e55d1eb51022c99
...
Processing artifact [378/379]: ose-local-storage-operator@sha256_0c81c2b79f79307305e51ce9d3837657cf9ba5866194e464b4d1b299f85034d0
Processing artifact [379/379]: multicluster-operators-channel-rhel8@sha256_c10f6bbb84fe36e05816e873a72188018856ad6aac6cc16271a1b3966f73ceb3
...
Summary:

Release:                            4.14.0
Hub Version:                        2.6.3
ACM Version:                        2.6.3
MCE Version:                        2.1.4
Include DU Profile:                 Yes
Workers:                            83

18.14.4.5. Pre-caching custom images in disconnected environments

The --generate-imageset argument stops the factory-precaching-cli tool after the ImageSetConfiguration custom resource (CR) is generated. This allows you to customize the ImageSetConfiguration CR before downloading any images. After you customized the CR, you can use the --skip-imageset argument to download the images that you specified in the ImageSetConfiguration CR.

You can customize the ImageSetConfiguration CR in the following ways:

Add Operators and additional images
Remove Operators and additional images
Change Operator and catalog sources to local or disconnected registries

Procedure

Pre-cache the images:

# podman run -v /mnt:/mnt -v /root/.docker:/root/.docker --privileged --rm quay.io/openshift-kni/telco-ran-tools:latest -- factory-precaching-cli download \ 1
   -r 4.14.0 \ 2
   --acm-version 2.6.3 \ 3
   --mce-version 2.1.4 \ 4
   -f /mnt \ 5
   --img quay.io/custom/repository 6
   --du-profile -s \ 7
   --generate-imageset 8

1: Specifies the downloading function of the factory-precaching-cli tool.
2: Defines the OpenShift Container Platform release version.
3: Defines the RHACM version.
4: Defines the multicluster engine version.
5: Defines the folder where you want to download the images on the disk.
6: Optional. Defines the repository where you store your additional images. These images are downloaded and pre-cached on the disk.
7: Specifies pre-caching the Operators included in the DU configuration.
8: The --generate-imageset argument generates the ImageSetConfiguration CR only, which allows you to customize the CR.

Example output

Generated /mnt/imageset.yaml

Example ImageSetConfiguration CR

apiVersion: mirror.openshift.io/v1alpha2
kind: ImageSetConfiguration
mirror:
  platform:
    channels:
    - name: stable-4.14
      minVersion: 4.14.0 1
      maxVersion: 4.14.0
  additionalImages:
    - name: quay.io/custom/repository
  operators:
    - catalog: registry.redhat.io/redhat/redhat-operator-index:v4.14
      packages:
        - name: advanced-cluster-management 2
          channels:
             - name: 'release-2.6'
               minVersion: 2.6.3
               maxVersion: 2.6.3
        - name: multicluster-engine 3
          channels:
             - name: 'stable-2.1'
               minVersion: 2.1.4
               maxVersion: 2.1.4
        - name: local-storage-operator 4
          channels:
            - name: 'stable'
        - name: ptp-operator 5
          channels:
            - name: 'stable'
        - name: sriov-network-operator 6
          channels:
            - name: 'stable'
        - name: cluster-logging 7
          channels:
            - name: 'stable'
        - name: lvms-operator 8
          channels:
            - name: 'stable-4.14'
        - name: amq7-interconnect-operator 9
          channels:
            - name: '1.10.x'
        - name: bare-metal-event-relay 10
          channels:
            - name: 'stable'
    - catalog: registry.redhat.io/redhat/certified-operator-index:v4.14
      packages:
        - name: sriov-fec 11
          channels:
            - name: 'stable'

1: The platform versions match the versions passed to the tool.
2 3: The versions of RHACM and the multicluster engine Operator match the versions passed to the tool.
4 5 6 7 8 9 10 11: The CR contains all the specified DU Operators.

Customize the catalog resource in the CR:

apiVersion: mirror.openshift.io/v1alpha2
kind: ImageSetConfiguration
mirror:
  platform:
[...]
  operators:
    - catalog: eko4.cloud.lab.eng.bos.redhat.com:8443/redhat/certified-operator-index:v4.14
      packages:
        - name: sriov-fec
          channels:
            - name: 'stable'

When you download images by using a local or disconnected registry, you have to first add certificates for the registries that you want to pull the content from.

To avoid any errors, copy the registry certificate into your server:
```
# cp /tmp/eko4-ca.crt /etc/pki/ca-trust/source/anchors/.
```
Then, update the certificates trust store:
```
# update-ca-trust
```
Mount the host /etc/pki folder into the factory-cli image:
```
# podman run -v /mnt:/mnt -v /root/.docker:/root/.docker -v /etc/pki:/etc/pki --privileged --rm quay.io/openshift-kni/telco-ran-tools:latest -- \
factory-precaching-cli download \ 1
   -r 4.14.0 \ 2
   --acm-version 2.6.3 \ 3
   --mce-version 2.1.4 \ 4
   -f /mnt \ 5
   --img quay.io/custom/repository 6
   --du-profile -s \ 7
   --skip-imageset 8
```
1
Specifies the downloading function of the factory-precaching-cli tool.
2
Defines the OpenShift Container Platform release version.
3
Defines the RHACM version.
4
Defines the multicluster engine version.
5
Defines the folder where you want to download the images on the disk.
6
Optional. Defines the repository where you store your additional images. These images are downloaded and pre-cached on the disk.
7
Specifies pre-caching the Operators included in the DU configuration.
8
The --skip-imageset argument allows you to download the images that you specified in your customized ImageSetConfiguration CR.

Download the images without generating a new imageSetConfiguration CR:

# podman run -v /mnt:/mnt -v /root/.docker:/root/.docker --privileged --rm quay.io/openshift-kni/telco-ran-tools:latest -- factory-precaching-cli download -r 4.14.0 \
--acm-version 2.6.3 --mce-version 2.1.4 -f /mnt \
--img quay.io/custom/repository \
--du-profile -s \
--skip-imageset

Additional resources

To access the online Red Hat registries, see OpenShift installation customization tools.
For more information about using the multicluster engine, see About cluster lifecycle with the multicluster engine operator.

18.14.5. Pre-caching images in GitOps ZTP

The SiteConfig manifest defines how an OpenShift cluster is to be installed and configured. In the GitOps Zero Touch Provisioning (ZTP) provisioning workflow, the factory-precaching-cli tool requires the following additional fields in the SiteConfig manifest:

clusters.ignitionConfigOverride
nodes.installerArgs
nodes.ignitionConfigOverride

Example SiteConfig with additional fields

apiVersion: ran.openshift.io/v1
kind: SiteConfig
metadata:
  name: "example-5g-lab"
  namespace: "example-5g-lab"
spec:
  baseDomain: "example.domain.redhat.com"
  pullSecretRef:
    name: "assisted-deployment-pull-secret"
  clusterImageSetNameRef: "img4.9.10-x86-64-appsub" 1
  sshPublicKey: "ssh-rsa ..."
  clusters:
  - clusterName: "sno-worker-0"
    clusterImageSetNameRef: "eko4-img4.11.5-x86-64-appsub" 2
    clusterLabels:
      group-du-sno: ""
      common-411: true
      sites : "example-5g-lab"
      vendor: "OpenShift"
    clusterNetwork:
      - cidr: 10.128.0.0/14
        hostPrefix: 23
    machineNetwork:
      - cidr: 10.19.32.192/26
    serviceNetwork:
      - 172.30.0.0/16
    networkType: "OVNKubernetes"
    additionalNTPSources:
      - clock.corp.redhat.com
    ignitionConfigOverride:
      '{
        "ignition": {
          "version": "3.1.0"
        },
        "systemd": {
          "units": [
            {
              "name": "var-mnt.mount",
              "enabled": true,
              "contents": "[Unit]\nDescription=Mount partition with artifacts\nBefore=precache-images.service\nBindsTo=precache-images.service\nStopWhenUnneeded=true\n\n[Mount]\nWhat=/dev/disk/by-partlabel/data\nWhere=/var/mnt\nType=xfs\nTimeoutSec=30\n\n[Install]\nRequiredBy=precache-images.service"
            },
            {
              "name": "precache-images.service",
              "enabled": true,
              "contents": "[Unit]\nDescription=Extracts the precached images in discovery stage\nAfter=var-mnt.mount\nBefore=agent.service\n\n[Service]\nType=oneshot\nUser=root\nWorkingDirectory=/var/mnt\nExecStart=bash /usr/local/bin/extract-ai.sh\n#TimeoutStopSec=30\n\n[Install]\nWantedBy=multi-user.target default.target\nWantedBy=agent.service"
            }
          ]
        },
        "storage": {
          "files": [
            {
              "overwrite": true,
              "path": "/usr/local/bin/extract-ai.sh",
              "mode": 755,
              "user": {
                "name": "root"
              },
              "contents": {
                "source": "data:,%23%21%2Fbin%2Fbash%0A%0AFOLDER%3D%22%24%7BFOLDER%3A-%24%28pwd%29%7D%22%0AOCP_RELEASE_LIST%3D%22%24%7BOCP_RELEASE_LIST%3A-ai-images.txt%7D%22%0ABINARY_FOLDER%3D%2Fvar%2Fmnt%0A%0Apushd%20%24FOLDER%0A%0Atotal_copies%3D%24%28sort%20-u%20%24BINARY_FOLDER%2F%24OCP_RELEASE_LIST%20%7C%20wc%20-l%29%20%20%23%20Required%20to%20keep%20track%20of%20the%20pull%20task%20vs%20total%0Acurrent_copy%3D1%0A%0Awhile%20read%20-r%20line%3B%0Ado%0A%20%20uri%3D%24%28echo%20%22%24line%22%20%7C%20awk%20%27%7Bprint%241%7D%27%29%0A%20%20%23tar%3D%24%28echo%20%22%24line%22%20%7C%20awk%20%27%7Bprint%242%7D%27%29%0A%20%20podman%20image%20exists%20%24uri%0A%20%20if%20%5B%5B%20%24%3F%20-eq%200%20%5D%5D%3B%20then%0A%20%20%20%20%20%20echo%20%22Skipping%20existing%20image%20%24tar%22%0A%20%20%20%20%20%20echo%20%22Copying%20%24%7Buri%7D%20%5B%24%7Bcurrent_copy%7D%2F%24%7Btotal_copies%7D%5D%22%0A%20%20%20%20%20%20current_copy%3D%24%28%28current_copy%20%2B%201%29%29%0A%20%20%20%20%20%20continue%0A%20%20fi%0A%20%20tar%3D%24%28echo%20%22%24uri%22%20%7C%20%20rev%20%7C%20cut%20-d%20%22%2F%22%20-f1%20%7C%20rev%20%7C%20tr%20%22%3A%22%20%22_%22%29%0A%20%20tar%20zxvf%20%24%7Btar%7D.tgz%0A%20%20if%20%5B%20%24%3F%20-eq%200%20%5D%3B%20then%20rm%20-f%20%24%7Btar%7D.gz%3B%20fi%0A%20%20echo%20%22Copying%20%24%7Buri%7D%20%5B%24%7Bcurrent_copy%7D%2F%24%7Btotal_copies%7D%5D%22%0A%20%20skopeo%20copy%20dir%3A%2F%2F%24%28pwd%29%2F%24%7Btar%7D%20containers-storage%3A%24%7Buri%7D%0A%20%20if%20%5B%20%24%3F%20-eq%200%20%5D%3B%20then%20rm%20-rf%20%24%7Btar%7D%3B%20current_copy%3D%24%28%28current_copy%20%2B%201%29%29%3B%20fi%0Adone%20%3C%20%24%7BBINARY_FOLDER%7D%2F%24%7BOCP_RELEASE_LIST%7D%0A%0A%23%20workaround%20while%20https%3A%2F%2Fgithub.com%2Fopenshift%2Fassisted-service%2Fpull%2F3546%0A%23cp%20%2Fvar%2Fmnt%2Fmodified-rhcos-4.10.3-x86_64-metal.x86_64.raw.gz%20%2Fvar%2Ftmp%2F.%0A%0Aexit%200"
              }
            },
            {
              "overwrite": true,
              "path": "/usr/local/bin/agent-fix-bz1964591",
              "mode": 755,
              "user": {
                "name": "root"
              },
              "contents": {
                "source": "data:,%23%21%2Fusr%2Fbin%2Fsh%0A%0A%23%20This%20script%20is%20a%20workaround%20for%20bugzilla%201964591%20where%20symlinks%20inside%20%2Fvar%2Flib%2Fcontainers%2F%20get%0A%23%20corrupted%20under%20some%20circumstances.%0A%23%0A%23%20In%20order%20to%20let%20agent.service%20start%20correctly%20we%20are%20checking%20here%20whether%20the%20requested%0A%23%20container%20image%20exists%20and%20in%20case%20%22podman%20images%22%20returns%20an%20error%20we%20try%20removing%20the%20faulty%0A%23%20image.%0A%23%0A%23%20In%20such%20a%20scenario%20agent.service%20will%20detect%20the%20image%20is%20not%20present%20and%20pull%20it%20again.%20In%20case%0A%23%20the%20image%20is%20present%20and%20can%20be%20detected%20correctly%2C%20no%20any%20action%20is%20required.%0A%0AIMAGE%3D%24%28echo%20%241%20%7C%20sed%20%27s%2F%3A.%2A%2F%2F%27%29%0Apodman%20image%20exists%20%24IMAGE%20%7C%7C%20echo%20%22already%20loaded%22%20%7C%7C%20echo%20%22need%20to%20be%20pulled%22%0A%23podman%20images%20%7C%20grep%20%24IMAGE%20%7C%7C%20podman%20rmi%20--force%20%241%20%7C%7C%20true"
              }
            }
          ]
        }
      }'
    nodes:
      - hostName: "snonode.sno-worker-0.example.domain.redhat.com"
        role: "master"
        bmcAddress: "idrac-virtualmedia+https://10.19.28.53/redfish/v1/Systems/System.Embedded.1"
        bmcCredentialsName:
          name: "worker0-bmh-secret"
        bootMACAddress: "e4:43:4b:bd:90:46"
        bootMode: "UEFI"
        rootDeviceHints:
          deviceName: /dev/disk/by-path/pci-0000:01:00.0-scsi-0:2:0:0
        installerArgs: '["--save-partlabel", "data"]'
        ignitionConfigOverride: |
           {
            "ignition": {
              "version": "3.1.0"
            },
            "systemd": {
              "units": [
                {
                  "name": "var-mnt.mount",
                  "enabled": true,
                  "contents": "[Unit]\nDescription=Mount partition with artifacts\nBefore=precache-ocp-images.service\nBindsTo=precache-ocp-images.service\nStopWhenUnneeded=true\n\n[Mount]\nWhat=/dev/disk/by-partlabel/data\nWhere=/var/mnt\nType=xfs\nTimeoutSec=30\n\n[Install]\nRequiredBy=precache-ocp-images.service"
                },
                {
                  "name": "precache-ocp-images.service",
                  "enabled": true,
                  "contents": "[Unit]\nDescription=Extracts the precached OCP images into containers storage\nAfter=var-mnt.mount\nBefore=machine-config-daemon-pull.service nodeip-configuration.service\n\n[Service]\nType=oneshot\nUser=root\nWorkingDirectory=/var/mnt\nExecStart=bash /usr/local/bin/extract-ocp.sh\nTimeoutStopSec=60\n\n[Install]\nWantedBy=multi-user.target"
                }
              ]
            },
            "storage": {
              "files": [
                {
                  "overwrite": true,
                  "path": "/usr/local/bin/extract-ocp.sh",
                  "mode": 755,
                  "user": {
                    "name": "root"
                  },
                  "contents": {
                    "source": "data:,%23%21%2Fbin%2Fbash%0A%0AFOLDER%3D%22%24%7BFOLDER%3A-%24%28pwd%29%7D%22%0AOCP_RELEASE_LIST%3D%22%24%7BOCP_RELEASE_LIST%3A-ocp-images.txt%7D%22%0ABINARY_FOLDER%3D%2Fvar%2Fmnt%0A%0Apushd%20%24FOLDER%0A%0Atotal_copies%3D%24%28sort%20-u%20%24BINARY_FOLDER%2F%24OCP_RELEASE_LIST%20%7C%20wc%20-l%29%20%20%23%20Required%20to%20keep%20track%20of%20the%20pull%20task%20vs%20total%0Acurrent_copy%3D1%0A%0Awhile%20read%20-r%20line%3B%0Ado%0A%20%20uri%3D%24%28echo%20%22%24line%22%20%7C%20awk%20%27%7Bprint%241%7D%27%29%0A%20%20%23tar%3D%24%28echo%20%22%24line%22%20%7C%20awk%20%27%7Bprint%242%7D%27%29%0A%20%20podman%20image%20exists%20%24uri%0A%20%20if%20%5B%5B%20%24%3F%20-eq%200%20%5D%5D%3B%20then%0A%20%20%20%20%20%20echo%20%22Skipping%20existing%20image%20%24tar%22%0A%20%20%20%20%20%20echo%20%22Copying%20%24%7Buri%7D%20%5B%24%7Bcurrent_copy%7D%2F%24%7Btotal_copies%7D%5D%22%0A%20%20%20%20%20%20current_copy%3D%24%28%28current_copy%20%2B%201%29%29%0A%20%20%20%20%20%20continue%0A%20%20fi%0A%20%20tar%3D%24%28echo%20%22%24uri%22%20%7C%20%20rev%20%7C%20cut%20-d%20%22%2F%22%20-f1%20%7C%20rev%20%7C%20tr%20%22%3A%22%20%22_%22%29%0A%20%20tar%20zxvf%20%24%7Btar%7D.tgz%0A%20%20if%20%5B%20%24%3F%20-eq%200%20%5D%3B%20then%20rm%20-f%20%24%7Btar%7D.gz%3B%20fi%0A%20%20echo%20%22Copying%20%24%7Buri%7D%20%5B%24%7Bcurrent_copy%7D%2F%24%7Btotal_copies%7D%5D%22%0A%20%20skopeo%20copy%20dir%3A%2F%2F%24%28pwd%29%2F%24%7Btar%7D%20containers-storage%3A%24%7Buri%7D%0A%20%20if%20%5B%20%24%3F%20-eq%200%20%5D%3B%20then%20rm%20-rf%20%24%7Btar%7D%3B%20current_copy%3D%24%28%28current_copy%20%2B%201%29%29%3B%20fi%0Adone%20%3C%20%24%7BBINARY_FOLDER%7D%2F%24%7BOCP_RELEASE_LIST%7D%0A%0Aexit%200"
                  }
                }
              ]
            }
           }
        nodeNetwork:
          config:
            interfaces:
              - name: ens1f0
                type: ethernet
                state: up
                macAddress: "AA:BB:CC:11:22:33"
                ipv4:
                  enabled: true
                  dhcp: true
                ipv6:
                  enabled: false
          interfaces:
            - name: "ens1f0"
              macAddress: "AA:BB:CC:11:22:33"

1: Specifies the cluster image set used for deployment, unless you specify a different image set in the spec.clusters.clusterImageSetNameRef field.
2: Specifies the cluster image set used to deploy an individual cluster. If defined, it overrides the spec.clusterImageSetNameRef at the site level.

18.14.5.1. Understanding the clusters.ignitionConfigOverride field

The clusters.ignitionConfigOverride field adds a configuration in Ignition format during the GitOps ZTP discovery stage. The configuration includes systemd services in the ISO mounted in virtual media. This way, the scripts are part of the discovery RHCOS live ISO and they can be used to load the Assisted Installer (AI) images.

systemd services: The systemd services are var-mnt.mount and precache-images.services. The precache-images.service depends on the disk partition to be mounted in /var/mnt by the var-mnt.mount unit. The service calls a script called extract-ai.sh.
extract-ai.sh: The extract-ai.sh script extracts and loads the required images from the disk partition to the local container storage. When the script finishes successfully, you can use the images locally.
agent-fix-bz1964591: The agent-fix-bz1964591 script is a workaround for an AI issue. To prevent AI from removing the images, which can force the agent.service to pull the images again from the registry, the agent-fix-bz1964591 script checks if the requested container images exist.

18.14.5.2. Understanding the nodes.installerArgs field

The nodes.installerArgs field allows you to configure how the coreos-installer utility writes the RHCOS live ISO to disk. You need to indicate to save the disk partition labeled as data because the artifacts saved in the data partition are needed during the OpenShift Container Platform installation stage.

The extra parameters are passed directly to the coreos-installer utility that writes the live RHCOS to disk. On the next reboot, the operating system starts from the disk.

You can pass several options to the coreos-installer utility:

OPTIONS:
...
    -u, --image-url <URL>
            Manually specify the image URL

    -f, --image-file <path>
            Manually specify a local image file

    -i, --ignition-file <path>
            Embed an Ignition config from a file

    -I, --ignition-url <URL>
            Embed an Ignition config from a URL
...
        --save-partlabel <lx>...
            Save partitions with this label glob

        --save-partindex <id>...
            Save partitions with this number or range
...
        --insecure-ignition
            Allow Ignition URL without HTTPS or hash

18.14.5.3. Understanding the nodes.ignitionConfigOverride field

Similarly to clusters.ignitionConfigOverride, the nodes.ignitionConfigOverride field allows the addition of configurations in Ignition format to the coreos-installer utility, but at the OpenShift Container Platform installation stage. When the RHCOS is written to disk, the extra configuration included in the GitOps ZTP discovery ISO is no longer available. During the discovery stage, the extra configuration is stored in the memory of the live OS.

Note

At this stage, the number of container images extracted and loaded is bigger than in the discovery stage. Depending on the OpenShift Container Platform release and whether you install the Day-2 Operators, the installation time can vary.

At the installation stage, the var-mnt.mount and precache-ocp.services systemd services are used.

precache-ocp.service: The precache-ocp.service depends on the disk partition to be mounted in /var/mnt by the var-mnt.mount unit. The precache-ocp.service service calls a script called extract-ocp.sh.
Important
To extract all the images before the OpenShift Container Platform installation, you must execute precache-ocp.service before executing the machine-config-daemon-pull.service and nodeip-configuration.service services.
extract-ocp.sh: The extract-ocp.sh script extracts and loads the required images from the disk partition to the local container storage. When the script finishes successfully, you can use the images locally.

When you upload the SiteConfig and the optional PolicyGenTemplates custom resources (CRs) to the Git repo, which Argo CD is monitoring, you can start the GitOps ZTP workflow by syncing the CRs with the hub cluster.

18.14.6. Troubleshooting

18.14.6.1. Rendered catalog is invalid

When you download images by using a local or disconnected registry, you might see the The rendered catalog is invalid error. This means that you are missing certificates of the new registry you want to pull content from.

Note

The factory-precaching-cli tool image is built on a UBI RHEL image. Certificate paths and locations are the same on RHCOS.

Example error

Generating list of pre-cached artifacts...
error: unable to run command oc-mirror -c /mnt/imageset.yaml file:///tmp/fp-cli-3218002584/mirror --ignore-history --dry-run: Creating directory: /tmp/fp-cli-3218002584/mirror/oc-mirror-workspace/src/publish
Creating directory: /tmp/fp-cli-3218002584/mirror/oc-mirror-workspace/src/v2
Creating directory: /tmp/fp-cli-3218002584/mirror/oc-mirror-workspace/src/charts
Creating directory: /tmp/fp-cli-3218002584/mirror/oc-mirror-workspace/src/release-signatures
backend is not configured in /mnt/imageset.yaml, using stateless mode
backend is not configured in /mnt/imageset.yaml, using stateless mode
No metadata detected, creating new workspace
level=info msg=trying next host error=failed to do request: Head "https://eko4.cloud.lab.eng.bos.redhat.com:8443/v2/redhat/redhat-operator-index/manifests/v4.11": x509: certificate signed by unknown authority host=eko4.cloud.lab.eng.bos.redhat.com:8443

The rendered catalog is invalid.

Run "oc-mirror list operators --catalog CATALOG-NAME --package PACKAGE-NAME" for more information.

error: error rendering new refs: render reference "eko4.cloud.lab.eng.bos.redhat.com:8443/redhat/redhat-operator-index:v4.11": error resolving name : failed to do request: Head "https://eko4.cloud.lab.eng.bos.redhat.com:8443/v2/redhat/redhat-operator-index/manifests/v4.11": x509: certificate signed by unknown authority

Procedure

Copy the registry certificate into your server:

# cp /tmp/eko4-ca.crt /etc/pki/ca-trust/source/anchors/.

Update the certificates truststore:
```
# update-ca-trust
```

Mount the host /etc/pki folder into the factory-cli image:

# podman run -v /mnt:/mnt -v /root/.docker:/root/.docker -v /etc/pki:/etc/pki --privileged -it --rm quay.io/openshift-kni/telco-ran-tools:latest -- \
factory-precaching-cli download -r 4.14.0 --acm-version 2.5.4 \
   --mce-version 2.0.4 -f /mnt \--img quay.io/custom/repository
   --du-profile -s --skip-imageset

Legal Notice

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Modified versions must remove all Red Hat trademarks.

Portions adapted from https://github.com/kubernetes-incubator/service-catalog/ with modifications by Red Hat.

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Scalability and performance

Scaling your OpenShift Container Platform cluster and tuning performance in production environments

Chapter 1. OpenShift Container Platform scalability and performance overview

Recommended performance and scalability practices

Telco reference design specifications

Planning, optimization, and measurement

Chapter 2. Recommended performance and scalability practices

2.1. Recommended control plane practices

2.1.1. Recommended practices for scaling the cluster

2.1.2. Control plane node sizing

2.1.2.1. Selecting a larger Amazon Web Services instance type for control plane machines

2.1.2.1.1. Changing the Amazon Web Services instance type by using a control plane machine set

2.1.2.1.2. Changing the Amazon Web Services instance type by using the AWS console

2.2. Recommended infrastructure practices

2.2.1. Infrastructure node sizing

2.2.2. Scaling the Cluster Monitoring Operator

2.2.3. Prometheus database storage requirements

2.2.4. Configuring cluster monitoring

2.2.5. Additional resources

2.3. Recommended etcd practices

2.3.1. Recommended etcd practices

2.3.2. Moving etcd to a different disk

2.3.3. Defragmenting etcd data

2.3.3.1. Automatic defragmentation

2.3.3.2. Manual defragmentation

2.3.4. Setting tuning parameters for etcd

2.3.4.1. Changing hardware speed tolerance

Chapter 3. Reference design specifications

3.1. Telco core and RAN DU reference design specifications

3.1.1. Reference design specifications for telco 5G deployments

3.1.2. Reference design scope

3.1.3. Deviations from the reference design

3.2. Telco RAN DU reference design specification

3.2.1. Telco RAN DU 4.14 reference design overview

3.2.1.1. OpenShift Container Platform 4.14 features for telco RAN DU

3.2.1.2. Deployment architecture overview

3.2.2. Telco RAN DU use model overview

3.2.2.1. Telco RAN DU application workloads

3.2.2.2. Telco RAN DU representative reference application workload characteristics

3.2.2.3. Telco RAN DU worker node cluster resource utilization

3.2.2.4. Hub cluster management characteristics

3.2.2.5. Telco RAN DU RDS components

3.2.3. Telco RAN DU 4.14 reference design components

3.2.3.1. Host firmware tuning

3.2.3.2. Node Tuning Operator

3.2.3.3. PTP Operator

3.2.3.4. SR-IOV Operator

3.2.3.5. Logging

3.2.3.6. SRIOV-FEC Operator

3.2.3.7. Local Storage Operator

3.2.3.8. LVMS Operator

3.2.3.9. Workload partitioning

3.2.3.10. Cluster tuning

3.2.3.11. Machine configuration

3.2.3.12. Reference design deployment components

3.2.3.12.1. Red Hat Advanced Cluster Management (RHACM)

3.2.3.12.2. Topology Aware Lifecycle Manager (TALM)

3.2.3.12.3. GitOps and GitOps ZTP plugins

3.2.3.12.4. Agent-based installer

3.2.3.13. Additional components

3.2.3.13.1. Bare Metal Event Relay

3.2.4. Telco RAN distributed unit (DU) reference configuration CRs

3.2.4.1. Day 2 Operators reference CRs

3.2.4.2. Cluster tuning reference CRs

3.2.4.3. Machine configuration reference CRs

3.2.4.4. YAML reference

3.2.4.4.1. Day 2 Operators reference YAML

3.2.4.4.2. Cluster tuning reference YAML

3.2.4.4.3. Machine configuration reference YAML

3.2.5. Telco RAN DU reference configuration software specifications

3.2.5.1. Telco RAN DU 4.14 validated software components

3.3. Telco core reference design specification

3.3.1. Telco core 4.14 reference design overview

3.3.1.1. OpenShift Container Platform 4.14 features for telco core

3.3.2. Telco core 4.14 use model overview

3.3.2.1. Common baseline model

3.3.2.1.1. Engineering Considerations common use model

3.3.2.1.2. Application workloads

3.3.3. Telco core reference design components

3.3.3.1. CPU partitioning and performance tuning