Changing the AZ of a Standby DB Instance

Scenarios

You can migrate a standby DB instance to another AZ in the same region as the original AZ.

Constraints

Only when a DB instance is available and its storage is not full, you can migrate its standby instance to another AZ.

Precautions

• Before the migration, check the resource usage of your DB instance to prevent resource overload from affecting workloads and the migration progress.
• During the migration, if there is a large amount of data being written to the primary instance (in synchronous replication mode), the write operations may be blocked after the migration.
• DDL operations will be suspended during the migration. To prevent service interruption, perform the migration during off-peak hours.
• After the migration, check your workloads and verify data.
• The migration duration is in direct proportion to the instance data volume.

Procedure

1. Log in to the management console.
2. Click in the upper left corner of the page and choose Databases > Relational Database Service.
3. On the Instances page, locate the target DB instance and choose More > Migrate Standby Instance to Another AZ in the Operation column.
4. On the displayed page, select a target AZ and click Submit.
5. Check the DB instance status on the Instances page.
   • During the migration process, the DB instance status is Migrating standby DB instance. You can view the progress on the Task Center page. For details, see Task Center.
   • In the upper right corner of the DB instance list, click to refresh the list. After the migration is complete, the DB instance status will become Available.
   • On the Overview page, find AZ and check the AZ hosting the standby DB instance.