Red Hat build of MicroShift

Enable workload partitioning

To enable workload partitioning on MicroShift, make the following configuration changes:

Update the MicroShift config.yaml file to include the kubelet configuration file.
Create the CRI-O systemd and configuration files.
Create and update the systemd configuration file for the MicroShift and CRI-O services respectively.

Procedure

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" 
  }
}
# ...
```
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 
  cpuManagerPolicy: static
  cpuManagerPolicyOptions:
    full-pcpus-only: "true" 
  cpuManagerReconcilePeriod: 5s
# ...

	Exclusive cpuset for the system daemons and the interrupts/timers.
	kubelet configuration sets the `CPUManagerPolicyOptions` option to `full-pcpus-only` to ensure allocation of whole cores to the containers workload.

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 # ...
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 # ...