Manually scaling a machine set

• Prerequisites
• Scaling a machine set manually
• The machine set deletion policy

You can add or remove an instance of a machine in a machine set.

Prerequisites

• If you enabled the cluster-wide proxy and scale up workers not included in networking.machineNetwork[].cidr from the installation configuration, you must add the workers to the Proxy object’s noProxy field to prevent connection issues.

Scaling a machine set manually

To add or remove an instance of a machine in a machine set, you can manually scale the machine set.

This guidance is relevant to fully automated, installer-provisioned infrastructure installations. Customized, user-provisioned infrastructure installations do not have machine sets.

Prerequisites

• Install an OKD cluster and the oc command line.

• Log in to oc as a user with cluster-admin permission.

Procedure

1. View the machine sets that are in the cluster:

   $ oc get machinesets -n openshift-machine-api

   The machine sets are listed in the form of <clusterid>-worker-<aws-region-az>.

2. Scale the machine set:

   $ oc scale --replicas=2 machineset <machineset> -n openshift-machine-api

   Or:

   $ oc edit machineset <machineset> -n openshift-machine-api

   You can scale the machine set up or down. It takes several minutes for the new machines to be available.

The machine set deletion policy

Random, Newest, and Oldest are the three supported deletion options. The default is Random, meaning that random machines are chosen and deleted when scaling machine sets down. The deletion policy can be set according to the use case by modifying the particular machine set:

spec:
  deletePolicy: <delete_policy>
  replicas: <desired_replica_count>

Specific machines can also be prioritized for deletion by adding the annotation machine.openshift.io/cluster-api-delete-machine to the machine of interest, regardless of the deletion policy.