How Does a Cloud Database Perform a Primary/Standby Switchover?

Failover (Automatic)

It is also called out-planned handover. If the primary DB instance fails, the system will automatically switch to the standby DB instance within 5 minutes. No human intervention is required. The connection IP address remains unchanged. DB instances cannot be accessed during the failover. You need to configure automatic reconnections between applications and RDS DB instances to ensure near-continuous availability.

Switchover (Manual)

It is also called out-planned handover. When a DB instance is running properly, you can manually perform a primary/standby switchover as required.

1. Log in to the management console.
2. Click in the upper left corner and select a region and a project.
3. Click Service List. Under Database, click Relational Database Service. The RDS console is displayed.
4. On the Instance Management page, click the target DB instance.
5. In the DB Information area on the displayed Basic Information page, click Switch in the DB Instance Type field.

   Alternatively, click in the DB instance topology on the Basic Information page to perform a primary/standby switchover.

   

   Primary/standby switchover may cause service interruption for some seconds or minutes (determined by the replication delay). If the primary/standby synchronization delay is too long, a small amount of data may get lost. To prevent traffic congestion, you are advised to perform switchover during off-peak hours.

6. In the Switch Primary/Standby Instances dialog box, click Yes to switch between the primary and standby DB instances.

   If the replication status is Available and the replication delay is greater than 300s, the primary/standby switchover task cannot be delivered.

7. After a switchover is successful, you can view and manage the DB instance on the Instance Management page.
   • During the switchover process, the DB instance status is Switchover in progress.
   • In the upper right corner of the DB instance list, click to refresh the list. After the switchover is successful, the DB instance status will become Available