When Does a Master/Standby Switchover Occur?¶
A master/standby switchover may occur in the following scenarios:
A master/standby switchover operation is initiated on the DCS Console.
If the master node of a master/standby instance fails, a master/standby switchover will be triggered.
For example, running commands that consume a lot of resources, such as KEYS commands, will cause CPU usage to spike and as result triggers a master/standby switchover.
If you restart a master/standby instance on the DCS console, a master/standby switchover will be triggered.
If you scale up a single-node or master/standby instance, a master/standby switchover will be triggered.
During scale-up, a new standby node with the new specifications is created. After full and incremental data on the master node is synchronized to the standby node, a master/standby switchover is performed and the original node is deleted.
After a master/standby switchover occurs, you will receive a notification. Check whether the client services are running properly. If not, check whether the TCP connection is normal and whether it can be re-established after the master/standby switchover to restore the services.