Switch over a MySQL cluster

You can initiate a switchover for a MySQL Replication Cluster. Then KubeBlocks switches the instance roles.

Before you start

• Make sure the cluster is running normally.

• Check whether the following role probe parameters exist to verify whether the role probe is enabled.

  kubectl get cd apecloud-mysql -o yaml
  >
  probes:
    roleProbe:
      failureThreshold: 2
      periodSeconds: 1
      timeoutSeconds: 1

Initiate the switchover

You can switch over a secondary of a MySQL Replication to the primary role, and the former primary instance to a secondary one.

• Initiate a switchover with a specified new primary instance.

  kbcli cluster promote mycluster --instance='mycluster-mysql-1'

• If there are multiple components, you can use --components to specify a component.

  kbcli cluster promote mycluster --instance='mycluster-mysql-1' --components='apecloud-mysql'

Verify the switchover

Check the instance status to verify whether the switchover is performed successfully.

kbcli cluster list-instances

Handle an exception

If an error occurs, refer to Handle an exception to troubleshoot the operation.