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Switch over a MySQL cluster

You can initiate a switchover for an ApeCloud MySQL RaftGroup by executing the kbcli or kubectl command. 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: 3
    periodSeconds: 2
    timeoutSeconds: 1

Initiate the switchover

You can switch over a follower of an ApeCloud MySQL RaftGroup to the leader role, and the former leader instance to a follower.

  • Initiate a switchover with no leader instance specified.

    kbcli cluster promote mycluster
  • Initiate a switchover with a specified new leader instance.

    kbcli cluster promote mycluster --instance='mycluster-mysql-2'
  • If there are multiple components, you can use --component to specify a component.

    kbcli cluster promote mycluster --instance='mycluster-mysql-2' --component='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.