Restarting an instance is a common operations and maintenance (O&M) operation. It is used to update the system, save configurations, handle cases where the number of database connections reaches the upper limit, or resolve performance issues.
Prerequisites
The instance must be in the Running status.
Impact
Restarting an instance causes a temporary service interruption. We recommend that you restart your instance during off-peak hours and ensure that your application has an automatic reconnection mechanism. Before you restart the instance, pause all write operations and make the necessary business arrangements. Proceed with caution.
Procedure
Log on to the RDS console. In the navigation pane on the left, click RDS Custom > Instances. Then, select a region at the top of the page.
Restart an instance.
Restart a single instance: In the Actions column of the target instance, click .

Alternatively, go to the Basic Information page of the instance and click the Instance Restart button.
Restart one or more instances: Select one or more instances, and then click Restart at the bottom of the page.

In the dialog box, click OK and wait for the instance to restart. After the restart is complete, the instance Status changes to Running.
Related API
Restart an RDS Custom instance: RebootRCInstance