PolarDB:Manage three-zone instances

Change the primary zone of an instance

1. Log on to the PolarDB for Xscale console.
2. In the top navigation bar, select the region where the target instance is located.
3. On the Instances page, click the PolarDB-X 2.0 tab.
4. Find the target instance and click its ID.
5. On the Basic information page of the instance, click Specify Primary Zone in the Topological information section.
6. In the Specify Primary Zone dialog box, select the zone that you want to specify as the primary zone of the instance and click OK.
   Important Primary zone change operations cause transient connections. We recommend that you change the primary zone during off-peak hours.

   After you change the primary zone of the instance, the status of the instance changes to HA switching. After the status of the instance becomes Running, the primary zone of the instance is changed to the specified zone.

How to resolve the issue in which specific leader nodes are not deployed in the primary zone of the instance

• Q: The system uses data nodes of an instance in high availability mode. As a result, specific data nodes that are not deployed in the primary zone of the instance are used as leader data nodes.
• A: To resolve this issue, click Specify Primary Zone in the Topological information section on the Basic information page of the instance. In the Primary Zone drop-down list, select the ID of the primary zone of the instance and click OK.

  The status of the instance changes to HA switching. After the status of the instance becomes Running, you can view that the zones of all leader data nodes and Global Meta Service (GMS) nodes are the same as the primary zone of the instance.

  Important Primary zone change operations cause transient connections. We recommend that you change the primary zone during off-peak hours.