When you change the configuration of an ApsaraDB RDS for MySQL instance or upgrade the major engine version of the RDS instance, an instance switchover occurs. As a result, the RDS instance becomes unavailable for less than 30 seconds. You must perform the preceding operations during off-peak hours and make sure that your application is configured to automatically reconnect to the RDS instance.
Impacts
We recommend that you perform operations that involve instance switchovers during off-peak hours and make sure that your application is configured to automatically reconnect to your RDS instance.
If you perform operations that involve instance switchovers on an RDS instance that runs RDS Cluster Edition or RDS High-availability Edition, a primary/secondary switchover occurs. As a result, there can be a service interruption that usually lasts less than 30 seconds. Make sure that your application is configured to automatically reconnect to your database system. For more information, see Switch workloads over between primary and secondary ApsaraDB RDS for MySQL instances.
NoteWhen you change the configuration of an RDS instance, if the resources on the host on which the RDS instance resides are insufficient, the system automatically creates a new RDS instance on a host that has sufficient resources and synchronizes the data of the original RDS instance to the new RDS instance. The synchronization does not affect your use of the original RDS instance. After the synchronization is complete, an instance switchover occurs, and your database system becomes unavailable for approximately 30 to 120 seconds.
If you perform operations that involve instance switchovers on an RDS instance that runs RDS Basic Edition, an instance switchover occurs. As a result, the RDS instance becomes unavailable for a long period of time. The time required for the instance switchover varies based on the volume of data on the RDS instance.
A switchover may take longer when an instance fails.