When adjusting database resources at the AZ level, you may consider deactivating all AZs with a low resource utilization. In this case, you need to migrate the data in these AZs to other AZs without affecting the normal operations of the current business.
Solution
For convenience considerations, we recommend that you migrate data with the following solutions.
If the current instance is deployed in one single AZ, and all resources in the AZ are to be deactivated, you can use the following data migration scheme:
If the current instance is deployed in multiple AZs, and its master or replica AZ is to be deactivated:
If the master AZ is to be deactivated, manually promote the replica AZ to master AZ, add a new replica for the instance and specify another AZ for it, and delete the replica node in the original master AZ.
If the AZ of the current instance is to be changed, data needs to be migrated as detailed below. We recommend that you perform the migration during the maintenance time. For more information, see Setting Maintenance Time.
1. Upgrade the current single-AZ deployed instance to a multi-AZ deployed instance as instructed in Upgrading to Multi-AZ Deployment.
After upgrading to multi-AZ deployment, you can see the
icon next to the AZ of the instance in the AZ column in the instance list or in the Basic Info section on the Instance Details page.
Hover over
and you can see that the AZ information of the master and replica nodes of the current instance has not changed.
2. Promote the AZ of the new replica to master AZ.
In the instance list, find the target instance, and click Instance ID.
Enter the Instance Details page, select Node Management tab, and click Promote Replica to Master to set the AZ of replica node as the master AZ. For more information, see Manually Promoting to Master Node (Group).
3. Delete all nodes in the original master AZ to clear resources.
Notes:
On the Node Management tab in the console, you can see that the original master AZ has been automatically switched to the replica AZ, and all nodes in it have been changed to replica nodes.
On the instance management page, click More > Delete Replica.
On the Configure page, select replicas to be deleted for standard architecture and the replica group for cluster architecture, and click OK.
Multi-AZ deployment
If the master AZ is to be deactivated, data needs to be migrated as detailed below. We recommend that you perform the migration during the maintenance time. For more information, see Setting Maintenance Time.
1. Manually promote a replica AZ to master AZ. For more information, see step3 in single-AZ deployment inAZ Migration Scheme > Directions.
