Promoting a Read Replica to Primary

Scenarios

RDS enables you to promote a read replica into a single DB instance. When you promote a read replica, replication is stopped. After the promotion is complete, the read replica is available as a single DB instance. This operation does not affect the performance of the original DB instance.

If your DB instance fails and you want to quickly obtain a readable and writable instance, you can promote one of the instance's read replicas to primary.

Constraints

• This function is available only to RDS for MySQL 5.7 and 8.0.
• Only pay-per-use read replicas can be changed to single DB instances.
• This function is unavailable for DB instances with proxy enabled.
• Only general-purpose and Kunpeng general-enhanced read replicas using cloud SSDs can be promoted to single DB instances.

Procedure

1. Log in to the management console.
2. Click in the upper left corner and select a region.
3. Click in the upper left corner of the page and choose Databases > Relational Database Service.
4. On the Instances page, locate the target read replica and choose More > Promote to Primary in the Operation column.
5. View the read replica status on the Instances page.
   • During the promotion, the read replica status is Promoting to primary.
   • Refresh the DB instance list by clicking to see if the promotion is complete. After the promotion is complete, the read replica is disassociated from the original DB instance and is available as a single DB instance.
   • The billing mode on the new DB instance remains unchanged.