Chapter 3. Reference design specifications
3.1. Telco core and RAN DU reference design specifications Copy linkLink copied to clipboard!
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 Copy linkLink copied to clipboard!
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 Copy linkLink copied to clipboard!
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.
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 Copy linkLink copied to clipboard!
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.
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.
NoteRed Hat prioritizes the servicing of requests for deviations based on partner engagement priorities.
3.2. Telco RAN DU reference design specification Copy linkLink copied to clipboard!
3.2.1. Telco RAN DU 4.14 reference design overview Copy linkLink copied to clipboard!
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 Copy linkLink copied to clipboard!
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.
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. |
Using custom CRs alongside the reference CRs in GitOps ZTP |
You can now use custom CRs alongside the reference configuration CRs provided in the |
Using custom node labels in the |
You can now use the |
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. |
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. |
PTP events and metrics |
The |
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. |
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: |
Set | single-node OpenShift clusters that run DU workloads require logging and log forwarding. |
3.2.1.2. Deployment architecture overview Copy linkLink copied to clipboard!
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
3.2.2. Telco RAN DU use model overview Copy linkLink copied to clipboard!
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 Copy linkLink copied to clipboard!
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
ortcpSocket
. - 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.
-
Do not use exec probes if a CNF uses CPU pinning. Use other probe implementations, for example,
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 Copy linkLink copied to clipboard!
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 4Secret
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 usageNoteYou 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])
query=avg_over_time(pod:container_cpu_usage:sum{namespace="openshift-kube-apiserver"}[30m])
Copy to Clipboard Copied! Toggle word wrap Toggle overflow - 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 Copy linkLink copied to clipboard!
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.
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.
3.2.2.4. Hub cluster management characteristics Copy linkLink copied to clipboard!
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
andobservability-controller
add-ons. SetObservability
to the default configuration.ImportantConfiguring 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.
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 Copy linkLink copied to clipboard!
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
Ensure that components that are not included in the telco RAN DU profile do not affect the CPU resources allocated to workload applications.
Out of tree drivers are not supported.
3.2.3. Telco RAN DU 4.14 reference design components Copy linkLink copied to clipboard!
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 Copy linkLink copied to clipboard!
- 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 thespec.clusters.nodes
field in theSiteConfig
CR that you use to install the cluster. For example:nodes: - hostName: "example-node1.example.com" ironicInspect: "enabled"
nodes: - hostName: "example-node1.example.com" ironicInspect: "enabled"
Copy to Clipboard Copied! Toggle word wrap Toggle overflow NoteThe telco RAN DU reference
SiteConfig
does not enable theironicInspect
field by default.- Limits and requirements
- Hyperthreading must be enabled
- Engineering considerations
Tune all settings for maximum performance
NoteYou can tune firmware selections for power savings at the expense of performance as required.
3.2.3.2. Node Tuning Operator Copy linkLink copied to clipboard!
- 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 profilePerformanceProfile
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.
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.
NoteYou 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.
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 Copy linkLink copied to clipboard!
- 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 Copy linkLink copied to clipboard!
- 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) andvfio
(DPDK) devices are supported. - Engineering considerations
-
Customer variation on the configuration and number of
SriovNetwork
andSriovNetworkNodePolicy
custom resources (CRs) is expected. -
IOMMU kernel command-line settings are applied with a
MachineConfig
CR at install time. This ensures that theSriovOperator
CR does not cause a reboot of the node when adding them.
-
Customer variation on the configuration and number of
3.2.3.5. Logging Copy linkLink copied to clipboard!
- 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.
NoteUse of fluentd in the RAN use model is deprecated.
3.2.3.6. SRIOV-FEC Operator Copy linkLink copied to clipboard!
- 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 thePF
requires the usage ofvfio-token
that is injected into Pods. TheVF
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.
-
The SRIOV-FEC Operator uses CPU cores from the
3.2.3.7. Local Storage Operator Copy linkLink copied to clipboard!
- 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 ofPV
resources that you create depends on your requirements. - Engineering considerations
-
Create backing storage for
PV
CRs before creating thePV
. 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.
-
Create backing storage for
3.2.3.8. LVMS Operator Copy linkLink copied to clipboard!
- New in this release
- No reference design updates in this release
- New in this release
-
Simplified LVMS
deviceSelector
logic -
LVM Storage with
ext4
andPV
resources
-
Simplified LVMS
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
Copy to Clipboard Copied! Toggle word wrap Toggle overflow - 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 Copy linkLink copied to clipboard!
- 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
cpuPartitioningMode: AllNodes
Copy to Clipboard Copied! Toggle word wrap Toggle overflow -
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
-
Configure partitions with extra
- Limits and requirements
-
Namespace
andPod
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 Copy linkLink copied to clipboard!
- New in this release
You can remove the Image Registry Operator by using the cluster capabilities feature.
NoteYou configure cluster capabilities by using the
spec.clusters.installConfigOverrides
field in theSiteConfig
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:
Expand 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
andtelemeter
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.NoteThe 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 Copy linkLink copied to clipboard!
- New in this release
-
Set
rcu_normal
after node recovery
-
Set
- 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 podimagePullPolicy
field toAlways
.Expand 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 Copy linkLink copied to clipboard!
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) Copy linkLink copied to clipboard!
- 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.
-
A single hub cluster supports up to 3500 deployed single-node OpenShift clusters with 5
- 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.
-
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
3.2.3.12.2. Topology Aware Lifecycle Manager (TALM) Copy linkLink copied to clipboard!
- 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
-
Progressively applies updates to fleets of clusters in user-configurable batches by using
- 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:Copy to Clipboard Copied! Toggle word wrap Toggle overflow
- 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. ThePreCachingConfig
CR must be applied before referencing it in theClusterGroupUpgrade
CR. - Create a recovery partition during installation if you opt to use the TALM backup and restore feature.
-
The
3.2.3.12.3. GitOps and GitOps ZTP plugins Copy linkLink copied to clipboard!
- 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 onPolicyGenTemplate
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 thekustomization.yaml
file. You add user-provided CRs to this subdirectory that you use with the predefined CRs that are specified in thePolicyGenTemplate
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:
- 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 thekustomization.yaml
file, which includes thePolicyGenTemplate
as a generator.NoteAlternative locations for the
/source-crs
directory are not supported in this context.
-
300
- 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 theSiteConfig
. With this feature, you can deploy multiple OpenShift Container Platform versions to managed clusters simultaneously. -
The
extraManifestPath
field of theSiteConfig
CR is deprecated from OpenShift Container Platform 4.15 and later. Use the newextraManifests.searchPaths
field instead.
-
To avoid confusion or unintentional overwriting of files when updating content, use unique and distinguishable names for user-provided CRs in the
3.2.3.12.4. Agent-based installer Copy linkLink copied to clipboard!
- 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.
NoteYou 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 Copy linkLink copied to clipboard!
3.2.3.13.1. Bare Metal Event Relay Copy linkLink copied to clipboard!
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.
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 Copy linkLink copied to clipboard!
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.
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 Copy linkLink copied to clipboard!
Component | Reference CR | Optional | New in this release |
---|---|---|---|
Cluster logging | No | No | |
Cluster logging | No | No | |
Cluster logging | No | No | |
Cluster logging | No | No | |
Cluster logging | No | No | |
Local Storage Operator | Yes | No | |
Local Storage Operator | Yes | No | |
Local Storage Operator | Yes | No | |
Local Storage Operator | Yes | No | |
Local Storage Operator | Yes | No | |
Node Tuning Operator | No | No | |
Node Tuning Operator | No | No | |
PTP fast event notifications | Yes | No | |
PTP Operator | No | No | |
PTP Operator | No | Yes | |
PTP Operator | No | No | |
PTP Operator | No | No | |
PTP Operator | No | No | |
PTP Operator | No | No | |
PTP Operator | No | No | |
SR-IOV FEC Operator | Yes | No | |
SR-IOV FEC Operator | Yes | No | |
SR-IOV FEC Operator | Yes | No | |
SR-IOV FEC Operator | Yes | No | |
SR-IOV Operator | No | No | |
SR-IOV Operator | No | No | |
SR-IOV Operator | No | No | |
SR-IOV Operator | No | No | |
SR-IOV Operator | No | No | |
SR-IOV Operator | No | No |
3.2.4.2. Cluster tuning reference CRs Copy linkLink copied to clipboard!
Component | Reference CR | Optional | New in this release |
---|---|---|---|
Cluster capabilities | No | No | |
Disabling network diagnostics | No | No | |
Monitoring configuration | No | No | |
OperatorHub | No | No | |
OperatorHub | No | No | |
OperatorHub | No | No | |
OperatorHub | No | No |
3.2.4.3. Machine configuration reference CRs Copy linkLink copied to clipboard!
Component | Reference CR | Optional | New in this release |
---|---|---|---|
Container runtime (crun) | No | No | |
Container runtime (crun) | No | No | |
Disabling CRI-O wipe | No | No | |
Disabling CRI-O wipe | No | No | |
Enabling kdump | No | Yes | |
Enabling kdump | No | Yes | |
Enabling kdump | No | No | |
Enabling kdump | No | No | |
Kubelet configuration and container mount hiding | No | No | |
Kubelet configuration and container mount hiding | No | No | |
One-shot time sync | No | Yes | |
One-shot time sync | No | Yes | |
SCTP | No | No | |
SCTP | No | No | |
Set RCU Normal | No | No | |
Set RCU Normal | No | No | |
SR-IOV related kernel arguments | No | Yes | |
SR-IOV related kernel arguments | No | No |
3.2.4.4. YAML reference Copy linkLink copied to clipboard!
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 Copy linkLink copied to clipboard!
ClusterLogForwarder.yaml
ClusterLogging.yaml
ClusterLogNS.yaml
ClusterLogOperGroup.yaml
ClusterLogSubscription.yaml
StorageClass.yaml
StorageLV.yaml
StorageNS.yaml
StorageOperGroup.yaml
StorageSubscription.yaml
PerformanceProfile.yaml
TunedPerformancePatch.yaml
PtpOperatorConfigForEvent.yaml
PtpConfigBoundary.yaml
PtpConfigGmWpc.yaml
PtpConfigSlave.yaml
PtpOperatorConfig.yaml
PtpSubscription.yaml
PtpSubscriptionNS.yaml
PtpSubscriptionOperGroup.yaml
AcceleratorsNS.yaml
apiVersion: v1 kind: Namespace metadata: name: vran-acceleration-operators annotations: {}
apiVersion: v1
kind: Namespace
metadata:
name: vran-acceleration-operators
annotations: {}
AcceleratorsOperGroup.yaml
AcceleratorsSubscription.yaml
SriovFecClusterConfig.yaml
SriovNetwork.yaml
SriovNetworkNodePolicy.yaml
SriovOperatorConfig.yaml
SriovSubscription.yaml
SriovSubscriptionNS.yaml
SriovSubscriptionOperGroup.yaml
3.2.4.4.2. Cluster tuning reference YAML Copy linkLink copied to clipboard!
example-sno.yaml
DisableSnoNetworkDiag.yaml
ReduceMonitoringFootprint.yaml
DisableOLMPprof.yaml
DefaultCatsrc.yaml
DisconnectedICSP.yaml
OperatorHub.yaml
3.2.4.4.3. Machine configuration reference YAML Copy linkLink copied to clipboard!
enable-crun-master.yaml
enable-crun-worker.yaml
99-crio-disable-wipe-master.yaml
99-crio-disable-wipe-worker.yaml
05-kdump-config-master.yaml
05-kdump-config-worker.yaml
06-kdump-master.yaml
06-kdump-worker.yaml
01-container-mount-ns-and-kubelet-conf-master.yaml
01-container-mount-ns-and-kubelet-conf-worker.yaml
99-sync-time-once-master.yaml
99-sync-time-once-worker.yaml
03-sctp-machine-config-master.yaml
03-sctp-machine-config-worker.yaml
08-set-rcu-normal-master.yaml
08-set-rcu-normal-worker.yaml
3.2.5. Telco RAN DU reference configuration software specifications Copy linkLink copied to clipboard!
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 Copy linkLink copied to clipboard!
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.
Component | Software version |
---|---|
Managed cluster version | 4.14 |
Cluster Logging Operator | 5.8 |
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 |
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 | 1.16 |
Topology Aware Lifecycle Manager (TALM) | 4.14 |
3.3. Telco core reference design specification Copy linkLink copied to clipboard!
3.3.1. Telco core 4.14 reference design overview Copy linkLink copied to clipboard!
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 Copy linkLink copied to clipboard!
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.
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. |
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 |
Enabling more control over the C-states for each pod |
The |
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. |
Egress service resource to manage egress traffic for pods behind a load balancer (Technology Preview) |
With this update, you can use an
You can use the
|
3.3.2. Telco core 4.14 use model overview Copy linkLink copied to clipboard!
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
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 Copy linkLink copied to clipboard!
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 Copy linkLink copied to clipboard!
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
setsgloballyDisableIrqLoadBalancing: 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 Copy linkLink copied to clipboard!
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.
-
Guaranteed QoS pods might be used but require correct configuration of reserved and isolated CPUs in the
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.
NoteStartup 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 Copy linkLink copied to clipboard!
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 Copy linkLink copied to clipboard!
- 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"
cpu-load-balancing.crio.io: "disable" cpu-quota.crio.io: "disable" irq-load-balancing.crio.io: "disable"
Copy to Clipboard Copied! Toggle word wrap Toggle overflow 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"
cpu-c-states.crio.io: "disable" cpu-freq-governor.crio.io: "performance"
Copy to Clipboard Copied! Toggle word wrap Toggle overflow
- 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.
-
The minimum reserved capacity (
3.3.3.2. Service Mesh Copy linkLink copied to clipboard!
- 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.
3.3.3.3. Networking Copy linkLink copied to clipboard!
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.
3.3.3.3.1. Cluster Network Operator (CNO) Copy linkLink copied to clipboard!
- 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.
-
Pod egress traffic is handled by kernel routing table with the
3.3.3.3.2. Load Balancer Copy linkLink copied to clipboard!
- 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.
3.3.3.3.3. SR-IOV Copy linkLink copied to clipboard!
- 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.
-
SR-IOV interfaces in
3.3.3.3.4. NMState Operator Copy linkLink copied to clipboard!
- 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.
-
The initial networking configuration is applied using
3.3.3.4. Logging Copy linkLink copied to clipboard!
- 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.
3.3.3.5. Power Management Copy linkLink copied to clipboard!
- 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.
-
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
3.3.3.6. Storage Copy linkLink copied to clipboard!
- 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.
NoteAll 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 Copy linkLink copied to clipboard!
- 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 Copy linkLink copied to clipboard!
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.
3.3.3.7. Monitoring Copy linkLink copied to clipboard!
- 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.
3.3.3.8. Scheduling Copy linkLink copied to clipboard!
- 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
totrue
in theSriovNetworkNodePolicy
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
orrestricted
.- 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.
3.3.3.9. Installation Copy linkLink copied to clipboard!
- 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.
3.3.3.10. Security Copy linkLink copied to clipboard!
- 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.
-
Configure the TAP plugin with the
- 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.
-
For rootless DPDK pod support, the SELinux boolean
3.3.3.11. Scalability Copy linkLink copied to clipboard!
- 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 Copy linkLink copied to clipboard!
3.3.3.12.1. Disconnected environment Copy linkLink copied to clipboard!
- 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 Copy linkLink copied to clipboard!
- 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.
NoteOut of tree drivers are not supported.
- Engineering considerations
- Not applicable
3.3.4. Telco core 4.14 reference configuration CRs Copy linkLink copied to clipboard!
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 Copy linkLink copied to clipboard!
Component | Reference CR | Optional | New in this release |
---|---|---|---|
System reserved capacity | Yes | No | |
System reserved capacity | Yes | No |
3.3.4.2. Storage reference CRs Copy linkLink copied to clipboard!
Component | Reference CR | Optional | New in this release |
---|---|---|---|
External ODF configuration | No | Yes | |
External ODF configuration | No | No | |
External ODF configuration | No | No | |
External ODF configuration | No | No |
3.3.4.3. Networking reference CRs Copy linkLink copied to clipboard!
Component | Reference CR | Optional | New in this release |
---|---|---|---|
Baseline | No | No | |
Baseline | Yes | Yes | |
Load balancer | No | No | |
Load balancer | No | No | |
Load balancer | No | No | |
Load balancer | No | No | |
Load balancer | No | No | |
Load balancer | Yes | No | |
Load balancer | Yes | No | |
Load balancer | No | No | |
Multus - Tap CNI for rootless DPDK pod | No | No | |
SR-IOV Network Operator | Yes | No | |
SR-IOV Network Operator | No | Yes | |
SR-IOV Network Operator | No | Yes | |
SR-IOV Network Operator | No | No | |
SR-IOV Network Operator | No | No | |
SR-IOV Network Operator | No | No |
3.3.4.4. Scheduling reference CRs Copy linkLink copied to clipboard!
Component | Reference CR | Optional | New in this release |
---|---|---|---|
NUMA-aware scheduler | No | No | |
NUMA-aware scheduler | No | No | |
NUMA-aware scheduler | No | No | |
NUMA-aware scheduler | No | No | |
NUMA-aware scheduler | No | No |
3.3.4.5. Other reference CRs Copy linkLink copied to clipboard!
Component | Reference CR | Optional | New in this release |
---|---|---|---|
Additional kernel modules | Yes | No | |
Additional kernel modules | Yes | No | |
Additional kernel modules | Yes | No | |
Cluster logging | No | No | |
Cluster logging | No | No | |
Cluster logging | No | No | |
Cluster logging | No | No | |
Cluster logging | No | Yes | |
Disconnected configuration | No | No | |
Disconnected configuration | No | No | |
Disconnected configuration | No | No | |
Monitoring and observability | Yes | No | |
Power management | No | No |
3.3.4.6. YAML reference Copy linkLink copied to clipboard!
3.3.4.6.1. Resource tuning reference YAML Copy linkLink copied to clipboard!
control-plane-system-reserved.yaml
pid-limits-cr.yaml
3.3.4.6.2. Storage reference YAML Copy linkLink copied to clipboard!
01-rook-ceph-external-cluster-details.secret.yaml
02-ocs-external-storagecluster.yaml
odfNS.yaml
odfOperGroup.yaml
3.3.4.6.3. Networking reference YAML Copy linkLink copied to clipboard!
Network.yaml
networkAttachmentDefinition.yaml
addr-pool.yaml
bfd-profile.yaml
bgp-advr.yaml
bgp-peer.yaml
metallb.yaml
metallbNS.yaml
metallbOperGroup.yaml
metallbSubscription.yaml
mc_rootless_pods_selinux.yaml
sriovNetwork.yaml
sriovNetworkNodePolicy.yaml
SriovOperatorConfig.yaml
SriovSubscription.yaml
SriovSubscriptionNS.yaml
SriovSubscriptionOperGroup.yaml
3.3.4.6.4. Scheduling reference YAML Copy linkLink copied to clipboard!
nrop.yaml
NROPSubscription.yaml
NROPSubscriptionNS.yaml
NROPSubscriptionOperGroup.yaml
sched.yaml
3.3.4.6.5. Other reference YAML Copy linkLink copied to clipboard!
control-plane-load-kernel-modules.yaml
sctp_module_mc.yaml
worker-load-kernel-modules.yaml
ClusterLogForwarder.yaml
ClusterLogging.yaml
ClusterLogNS.yaml
ClusterLogOperGroup.yaml
ClusterLogSubscription.yaml
catalog-source.yaml
icsp.yaml
operator-hub.yaml
monitoring-config-cm.yaml
PerformanceProfile.yaml