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Version: release-0.8

Switch over a MongoDB cluster

You can initiate a switchover for a MongoDB ReplicaSet by executing the kbcli or kubectl command. Then KubeBlocks modifies 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 mongodb -o yaml
    >
    probes:
    roleProbe:
    failureThreshold: 3
    periodSeconds: 2
    timeoutSeconds: 1

Initiate the switchover

You can switch over a secondary of a MongoDB ReplicaSet to the primary role, and the former primary instance to a secondary.

  • Switchover with no primary instance specified

    kbcli cluster promote mycluster
  • Switchover with a specified new primary instance

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

    kbcli cluster promote mycluster --instance='mycluster-mongodb-2' --component='mongodb'

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 exaception to troubleshoot the operation.