Software upgrade
ApsaraDB for RDS automatically applies new database engine versions to keep instances secure and stable. Understanding when and how upgrades occur lets you plan maintenance schedules and minimize application impact.
How upgrades work
Minor version upgrades are non-mandatory in almost all cases. The system upgrades the database engine to the latest compatible version only when you manually restart an RDS instance.
In rare cases — such as fatal major bugs and security vulnerabilities — RDS initiates a mandatory upgrade for affected instances during their maintenance window. Basic Edition instances are excluded from mandatory upgrades. A mandatory upgrade causes a brief database disconnection. If your application uses a connection pool that is configured properly, the disconnection has no adverse effect.
Set the maintenance window
Configure the maintenance window to prevent mandatory upgrades from running during peak hours. Use the console or API to adjust the window at any time.
For instructions, see Set the maintenance window of an ApsaraDB RDS for MySQL instance.