Upgrading a Minor Version

Scenarios

RDS for MySQL supports minor version upgrades to improve performance, add new functions, and fix bugs.

Precautions

• The upgrade will cause the DB instance to reboot and briefly interrupt services. To limit the impact of the upgrade, perform the upgrade during off-peak hours, or ensure that your applications support automatic reconnection.
• A minor version upgrade involves switchovers between primary and standby instances, which cause a brief service interruption. Besides, there can be two waits of up to 10s for a single SQL statement to update or write data because the default replication between primary and standby instances is semi-synchronous. To avoid the waits, change the replication mode to asynchronous before the upgrade.
• If primary and standby DB instances are deployed in the same AZ, a minor version upgrade will trigger a switchover. If they are deployed in different AZs, a minor version upgrade will trigger two switchovers.
• When you upgrade a minor version of a primary DB instance, minor versions of read replicas (if any) will also be upgraded automatically (they cannot be upgraded separately). Perform the upgrade during off-peak hours because the DB instance will be rebooted after the upgrade is complete.
• If your RDS instance is involved in a DRS task, upgrading the minor version may cause the DRS task to fail.
  You are advised to check the retention period of RDS instance binlogs before upgrading the minor version.

  • If the binlogs are within the retention period, the DRS task will automatically restart after the minor version is upgraded.
  • If the binlogs are beyond the retention period, you need to reconfigure or recreate a DRS task.
• A minor version upgrade cannot be rolled back after the upgrade is complete. If the upgrade fails, the DB instance will be automatically rolled back to the source version.
• You are advised to perform a full backup before upgrading a minor version.
• A minor version can be upgraded in minutes. Do not perform any of the following operations during an upgrade, as they can significantly increase the upgrade time:
  • Frequent access to system databases or tables such as performance_schema and mysql
  • Frequent writes causing a replication delay or high dirty page ratio of the buffer pool
• DDL operations on events, such as CREATE EVENT, DROP EVENT, and ALTER EVENT, are not allowed during a minor version upgrade. If there is any DDL operation, handle it by referring to What Can I Do If a DDL Operation Is Being Performed on the Primary Node During a Minor Version Upgrade?

Constraints

• If the replication delay between primary and standby DB instances is longer than 300 seconds, the minor version cannot be upgraded.
• Minor versions cannot be upgraded for DB instances with abnormal nodes.

Procedure

1. Log in to the management console.
2. Click in the upper left corner of the page and choose Databases > Relational Database Service.
3. On the Instances page, click the instance name to go to the Overview page.
4. On the Overview page, click Upgrade Minor Version next to DB Engine Version.

5. In the displayed dialog box, select a scheduled time and click OK.
6. After the upgrade is complete, the minor version of your instance becomes the latest minor version.