This topic describes the reasons why a primary/secondary switchover is triggered for an ApsaraDB RDS for MySQL instance.

A primary/secondary switchover is triggered due to one of the following reasons:

  • Vulnerabilities

    Alibaba Cloud detects vulnerabilities in each RDS instance. An RDS instance may fail to run as normal due to vulnerabilities. If this occurs, ApsaraDB RDS fixes the vulnerabilities in the secondary RDS instance of an RDS instance. Then, ApsaraDB RDS initiates a primary/secondary switchover during the specified maintenance window to switch your workloads over to the secondary RDS instance. For more information, see Set the maintenance window of an ApsaraDB RDS for MySQL instance. In most cases, if ApsaraDB RDS detects a high-risk vulnerability in an RDS instance, ApsaraDB RDS fixes the high-risk vulnerability at the earliest opportunity and triggers a primary/secondary switchover.

  • Manual operations

    You or an authorized Alibaba Cloud technical expert manually performs a primary/secondary switchover.

  • Instance failures

    Alibaba Cloud detects failures in each RDS instance. An RDS instance may fail to run as normal due to failures. If this occurs, ApsaraDB RDS initiates a primary/secondary switchover to switch your workloads over to the secondary RDS instance of an RDS instance. This minimizes the impacts of the failures.

After a primary/secondary switchover is complete, the status of an RDS instance shows as Running. You do not need to perform other operations, and an RDS instance can run as normal. If you want to view the primary/secondary switchover logs, go to the Primary/Secondary Switching Logs section of the Service Availability page in the ApsaraDB RDS console.

Primary/Secondary Switching Logs