Changing the AZ of a Standby DB Instance

You can migrate a standby DB instance to another AZ in the same region as the original AZ. The migration speed is about 150 MB/s. If a large amount of data is written during the migration, there may be a long replication delay between the primary and standby instances after the migration.

• RDS for MySQL primary/standby instances support standby instance migration to another AZ.
• Before changing the AZ of a standby instance, ensure that there are enough resources in the primary AZ and new standby AZ.
• Batch write operations during peak hours may cause migration failures. To ensure successful migration, perform the migration during off-peak hours.
• DDL operations and scheduled events will be suspended during migration. To prevent service interruptions, perform the migration during off-peak hours.
• During the migration, snapshots are taken for instances. However, full backups will not be triggered d once the migration is complete.

1. Log in to the management console.
2. Click in the upper left corner and select a region and a project.
3. Click in the upper left corner of the page and choose Database > Relational Database Service.
4. On the Instances page, locate the target DB instance and choose More > Migrate Standby DB Instance in the Operation column.
5. Select the target AZ and click Submit.
6. 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 Basic Information page, find AZ and check the AZ hosting the standby DB instance.