How to disable unidling across the cluster?

Solution Unverified - Updated -

Environment

  • OpenShift Container Platform (OCP) 3.9, 3.10 and 3.11

Issue

  • Unidling is causing iptables lock contention.
  • Is there a parameter to disable Unidling using the node-config.yaml?

Resolution

Please take into account that instruction differs between versions.
OCP 3.9

  • Add the parameter enableUnidling, set it to false in the configuration file /etc/origin/node/node-config.yaml.

    ...
 dockerConfig:
  dockerShimRootDirectory: /var/lib/dockershim
  dockerShimSocket: /var/run/dockershim.sock
  execHandlerName: native
enableUnidling: false
imageConfig:
  format: "{{ openshift_imageconfig_format }}"
  latest: false
iptablesSyncPeriod: 30s
...

  • Restart the atomic-openshift-node service.

    # systemctl restart atomic-openshift-node

OCP 3.10 and 3.11

Starting in OpenShift 3.10, the node configuration is managed by making updates to the configmaps for each type of node to be configured.

  • Edit the corresponding configmap. For example, to modify the compute configmap run the following:

    # oc edit cm/node-config-compute -n openshift-node

  • Add parameter enableUnidling, set it to false:

    ...
 dockerConfig:
  dockerShimRootDirectory: /var/lib/dockershim
  dockerShimSocket: /var/run/dockershim.sock
  execHandlerName: native
enableUnidling: false
imageConfig:
  format: "{{ openshift_imageconfig_format }}"
  latest: false
iptablesSyncPeriod: 30s
...

Root Cause

  • By default, the parameter enableUnidling is set to true in the node-config.yaml on the openshift-ansible template.

    openshift-ansible/roles/openshift_node_group/templates/node-config.yaml.j2
...
 dockerConfig:
  dockerShimRootDirectory: /var/lib/dockershim
  dockerShimSocket: /var/run/dockershim.sock
  execHandlerName: native
enableUnidling: true
imageConfig:
  format: "{{ openshift_imageconfig_format }}"
  latest: false
iptablesSyncPeriod: 30s
...

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