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Version: release-0.9

Switch over an ApeCloud 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.

    kubectl get cluster mycluster -n demo
    >
    NAME        CLUSTER-DEFINITION   VERSION           TERMINATION-POLICY   STATUS    AGE
    mycluster   apecloud-mysql       ac-mysql-8.0.30   Delete               Running   27m

  • 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 follower of an ApeCloud MySQL RaftGroup to the leader role, and the former leader instance to a follower.

The value of instanceName decides whether a new leader instance is specified for the switchover.

  • Initiate a switchover with no leader instance specified.

    kubectl apply -f -<<EOF
    apiVersion: apps.kubeblocks.io/v1alpha1
    kind: OpsRequest
    metadata:
      name: mycluster-switchover
      namespace: demo
    spec:
      clusterName: mycluster
      type: Switchover
      switchover:
      - componentName: apecloud-mysql
        instanceName: '*'
    EOF

  • Initiate a switchover with a specified new leader instance.

    kubectl apply -f -<<EOF
    apiVersion: apps.kubeblocks.io/v1alpha1
    kind: OpsRequest
    metadata:
      name: mycluster-switchover
      namespace: demo
    spec:
      clusterName: mycluster
      type: Switchover
      switchover:
      - componentName: apecloud-mysql
        instanceName: 'mycluster-mysql-2'
    EOF

Verify the switchover​

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

kubectl get pods -n demo

Handle an exception​

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