OpenShift Container Platform

Scale a compute machine set manually

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

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

Prerequisites

Install an OpenShift Container Platform cluster and the oc command line.
Log in to oc as a user with cluster-admin permission.

Procedure

View the compute machine sets that are in the cluster by running the following command:
```
$ oc get machinesets.machine.openshift.io -n openshift-machine-api
```
The compute machine sets are listed in the form of <clusterid>-worker-<aws-region-az>.
View the compute machines that are in the cluster by running the following command:
```
$ oc get machines.machine.openshift.io -n openshift-machine-api
```

Set the annotation on the compute machine that you want to delete by running the following command:

$ oc annotate machines.machine.openshift.io/<machine_name> -n openshift-machine-api machine.openshift.io/delete-machine="true"

Scale the compute machine set by running one of the following commands:

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

Or:

$ oc edit machinesets.machine.openshift.io <machineset> -n openshift-machine-api

You can alternatively apply the following YAML to scale the compute machine set:

apiVersion: machine.openshift.io/v1beta1
kind: MachineSet
metadata:
  name: <machineset>
  namespace: openshift-machine-api
spec:
  replicas: 2

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

By default, the machine controller tries to drain the node that is backed by the machine until it succeeds. In some situations, such as with a misconfigured pod disruption budget, the drain operation might not be able to succeed. If the drain operation fails, the machine controller cannot proceed removing the machine.

You can skip draining the node by annotating machine.openshift.io/exclude-node-draining in a specific machine.

Verification

Verify the deletion of the intended machine by running the following command:
```
$ oc get machines.machine.openshift.io
```