Performing a DR Switchover for the DWS Cluster

Application Scenarios

• Switching to the DR Cluster: Perform a switchover when the DR cluster is running properly. You can perform a DR switchover when the DR task is in the Running state.
• Performing an exception Switchover: Perform a switchover when the DR cluster is abnormal or the production cluster is faulty. You can perform such a switchover when the DR task is in the Abnormal state.
• Performing a DR Switchback: Perform a DR switchback after an exception switchover. Before the DR switchback, ensure that the original production cluster has been restored (you can contact technical support for assistance). The following figure shows the process.
  Figure 1 Exception switchover and switchback
  

Switching to the DR Cluster

Recovery Point Objective (RPO) refers to the point in time to which a system and data must be restored after a disaster occurs. The RPO is not 0, but data can be restored to at least the latest DR success time of the production cluster. For details, see Viewing DR Information.

1. Log in to the DWS console.
2. In the navigation pane on the left, choose Cluster > Management > DR Tasks.
3. Click More in the Operation column of the target DR task and select Switch to DR Cluster.
4. In the displayed dialog box, click OK.

   The DR status will change to DR switching. During this period, the original production cluster is unavailable.

   After the switchover is successful, the DR status will change to the original status.

Performing an exception Switchover

The production cluster is unavailable, the DR cluster is normal, and the DR status is Abnormal. DR exception switchover is supported only by clusters running version 8.1.2 or later.

1. Log in to the DWS console.
2. In the navigation pane on the left, choose Cluster > Management > DR Tasks.
3. Choose More > Exception Switchover in the Operation column of the target DR task.
4. In the displayed dialog box, click OK.
   • The Status will change to Switchover in progress.
   • After the switchover is successful, the DR status will change to the original status. In this procedure, the DR status will change back to Abnormal.
   • Before a switchover, check the latest synchronization time in the DR cluster. The DR cluster will serve as a production cluster after an exception switchover, but the data that failed to be synchronized from the original production cluster to the DR cluster will not exist in the DR cluster.

Performing a DR Switchback

After an exception switchover, if you have confirmed that the original production cluster was recovered, you can perform a switchback. DR switchback is supported only by clusters running version 8.1.2 or later.

1. Log in to the DWS console.
2. In the navigation pane on the left, choose Cluster > Management > DR Tasks.
3. Click More in the Operation column of a DR task and select DR Recovery.
4. In the displayed dialog box, set Synchronization Mode to Incremental or Full. You are advised to set Synchronization Mode to Incremental during DR rebuilding.
5. Click OK.
   • The Status will change to Recovering.
   • After the DR recovery is successful, the Status will change to Running.
   • During a DR switchback, data in the DR cluster will be deleted, and the DR relationship will be re-established with the new production cluster.