8.2. Workload partitioning

Procedure

1. Update the MicroShift config.yaml file to include the kubelet configuration file to enable and configure CPU Manager for the workloads:

   • Create the kubelet configuration file in the path /etc/kubernetes/openshift-workload-pinning. The kubelet configuration directs the kubelet to modify the node resources based on the capacity and allocatable CPUs.

     kubelet configuration example

     # ...
     {
       "management": {
         "cpuset": "0,6,7" 

     1

     
       }
     }
     # ...

     1

     The cpuset applies to a machine with 8 VCPUs (4 cores) and is valid throughout the document.

   • Update the MicroShift config.yaml file in the path /etc/microshift/config.yaml. Embed the kubelet configuration in the MicroShift config.yaml file to enable and configure CPU Manager for the workloads.

     MicroShift config.yaml example

     # ...
     kubelet:
       reservedSystemCPUs: 0,6,7 

     1

     
       cpuManagerPolicy: static
       cpuManagerPolicyOptions:
         full-pcpus-only: "true" 

     2

     
       cpuManagerReconcilePeriod: 5s
     # ...

     1

     Exclusive cpuset for the system daemons and the interrupts/timers.

     2

     kubelet configuration sets the CPUManagerPolicyOptions option to full-pcpus-only to ensure allocation of whole cores to the containers workload.

2. Create the CRI-O systemd and configuration files:

   • Create the CRI-O configuration file in the path /etc/crio/crio.conf.d/20-microshift-workload-partition.conf which overrides the default configuration that already exists in the 11-microshift-ovn.conf file.

     CRI-O configuration example

     # ...
     [crio.runtime]
     infra_ctr_cpuset = "0,6,7"
     
     [crio.runtime.workloads.management]
     activation_annotation = "target.workload.openshift.io/management"
     annotation_prefix = "resources.workload.openshift.io"
     resources = { "cpushares" = 0, "cpuset" = "0,6,7" }
     # ...

   • Create the systemd file for CRI-O in the path /etc/systemd/system/crio.service.d/microshift-cpuaffinity.conf.

     CRI-O systemd configuration example

     # ...
     [Service]
     CPUAffinity=0,6,7
     # ...

3. Create and update the systemd configuration file with CPUAffinity value for the MicroShift and CRI-O services:

   • Create the MicroShift services systemd file in the path /etc/systemd/system/microshift.service.d/microshift-cpuaffinity.conf. MicroShift will be pinned using the systemd CPUAffinity value.

     MicroShift services systemd configuration example

     # ...
     [Service]
     CPUAffinity=0,6,7
     # ...

   • Update the CPUAffinity value in the MicroShift ovs-vswitchd systemd file in the path /etc/systemd/system/ovs-vswitchd.service.d/microshift-cpuaffinity.conf.

     MicroShift ovs-vswitchd systemd configuration example

     # ...
     [Service]
     CPUAffinity=0,6,7
     # ...

   • Update the CPUAffinity value in the MicroShift ovsdb-server systemd file in the path /etc/systemd/system/ovsdb-server.service.d/microshift-cpuaffinity.conf

     MicroShift ovsdb-server systemd configuration example

     # ...
     [Service]
     CPUAffinity=0,6,7
     # ...