A primary/secondary switchover on an ApsaraDB RDS for MySQL instance is triggered by one of three events: vulnerability fixing, manual operations, or instance failures.
Vulnerability fixing
When Alibaba Cloud detects a vulnerability that may affect normal instance operation, the system first applies the fix to the secondary instance, then initiates a switchover during the maintenance window to transfer your workloads to the patched secondary instance.
If a high-risk vulnerability is detected, the switchover is triggered immediately and does not wait for the maintenance window.
No action is required. After the switchover completes, the instance status changes to Running.
Manual operations
A switchover is triggered manually by you or an authorized Alibaba Cloud technical expert. No further action is required after the switchover completes.
Instance failures
When Alibaba Cloud detects a failure that may affect normal instance operation, the system automatically initiates a switchover to transfer your workloads to the secondary instance.
If your instance experienced an unexpected switchover due to a failure, check the Primary/Secondary Switching Logs on the Service Availability page to identify the failure event.
After a switchover
After any switchover completes, the instance status changes to Running and the instance resumes normal operation. No additional steps are needed.
To view the switchover history, log on to the ApsaraDB RDS console, go to the Service Availability page of the instance, and check the Primary/Secondary Switching Logs section.
