Aurora MySQL Global Database Minor Version Update Not Possible

Hi,

Thank you so much for your question.

This upgrade path is currently not supported for in-place upgrade for Global Database cluster as stated in the release note[1], and Amazon Aurora Global Database documents.

Amazon Aurora MySQL3.04.0 release note

To perform a minor version upgrade for an Aurora global database from Aurora MySQL version 3.01, 3.02 or 3.03 to Aurora MySQL version 3.04 or higher, refer to Upgrading Aurora MySQL by modifying the engine version.

Amazon Aurora Global Database document

To perform a minor version upgrade to Aurora MySQL version 3.03.* or higher, or version 2.12.*, use the following process:

1. Remove all secondary Regions from the global cluster. Follow the steps in Removing a cluster from an Amazon Aurora global database.
2. Upgrade the engine version of the primary Region to version 3.03.* or higher, or version 2.12.*, as applicable. Follow the steps in To modify the engine version of a DB cluster.
3. Add secondary Regions to the global cluster. Follow the steps in Adding an AWS Region to an Amazon Aurora global database.

• [1] https://docs.aws.amazon.com/AmazonRDS/latest/AuroraMySQLReleaseNotes/AuroraMySQL.Updates.3040.html
• [2] https://docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide/AuroraMySQL.Updates.Patching.html#AuroraMySQL.Updates.Patching.ModifyEngineVersion

I hope this might help.