ApsaraDB RDS keeps your database software up to date through two upgrade paths: upgrades triggered by a manual instance restart, and mandatory updates initiated by the system in rare critical situations.
How upgrades work
Manual restart (most cases)
When you manually restart an ApsaraDB RDS instance, the system updates the database software to the latest compatible minor engine version. This is the standard, non-mandatory upgrade path and covers the vast majority of minor version upgrades.
System-initiated mandatory update (rare cases)
In rare cases — such as fatal major bugs and security vulnerabilities — ApsaraDB RDS initiates a mandatory update during the maintenance window. This applies to all instance editions except Basic Edition.
Usage notes
Temporary disconnection only: Mandatory updates cause temporary database disconnections. No other adverse impact occurs if your application uses a properly configured database connection pool.
Control upgrade timing: To prevent mandatory updates from running during peak hours, set a maintenance window using the console or API. See Set the maintenance window of an ApsaraDB RDS for MySQL instance.