Major Version Upgrade of an AWS RDS MySQL Instance

The following email arrived from AWS

[Action Required] Amazon RDS Extended Support opt-in behavior is changing. Upgrade your Amazon RDS for MySQL 5.7 database instances before February 29, 2024 to avoid potential increase in charges

In short, it says to upgrade RDS by February 29, 2024

This instance hadn't had major version maintenance in a long time, so I'm doing the major version upgrade at this timing.

Checking the current version

You can check the MySQL version of an RDS instance from the "Configuration" tab in the RDS console. My instance was on 5.7.43, and RDS standard support ends February 29, 2024 — I need to act fast!

Points to note when doing a major version upgrade

Compared with a minor version upgrade, there are far more fundamental fixes and improvements, so features and queries that worked on the original version may stop working. It's even possible that some features or queries only worked because of a bug in the old version, without you realizing it.

Before applying to production, we recommend building an environment on the post-upgrade version and testing all functionality.

During a major version upgrade, the MySQL binary mysql_upgrade runs and tables are upgraded. The slow_log and general_log tables are also emptied, so if you want to keep that log information, save the contents of the log files before the major version upgrade.

A normal major version upgrade completes in about 10 minutes, though the time varies with the instance type.

Verification steps for the upgrade

1. Check compatibility in the documentation

2. If you use a custom DB parameter group, create a new DB parameter group with the existing settings that are compatible with the new major version, and specify the new DB parameter group when you upgrade the test instance in step 5

3. Create a snapshot of the DB to be upgraded

4. Restore from the snapshot to create a new test DB

5. Upgrade the new test DB to the new version

6. Evaluate the storage used by the upgraded DB and determine whether the upgrade requires additional storage

7. Confirm that the DB on the new version and your application work correctly

Upgrade procedure

Select the DB instance to upgrade and click the [Modify] button.

Select the MySQL version to apply to RDS. This time I'll go with 8.0.35, the newest selectable at this point.

Click the [Continue] button at the very bottom of the screen.

Select [Apply immediately] and click the [Modify DB instance] button.

The status changes to [Upgrading], so wait a while.

After a while, the engine version had become 8.0.35.

That's the end of the major version upgrade.

Checking [Logs & events], there's a DB instance shutdown, so we can see there was downtime. However, it was only about 3 minutes until restarted, so the downtime appears to have been about 3 minutes.

The whole process completed in 8 minutes this time.