Unable to upgrade mysql_aurora version 2.12.24 to mysql_auroa_3.0.x version

I understand you're having difficulty upgrading your Aurora MySQL cluster from version 2.12.24 to version 3.0.x in the us-west-2 region, while you were successful in the ap-south-1 region. This situation suggests that there might be specific issues with the cluster in us-west-2 that are preventing the upgrade. Here are some potential reasons and steps to troubleshoot:

1. Global Database Configuration: If your Aurora cluster is part of a global database, you need to follow a specific process for upgrading. This involves removing all secondary regions from the global cluster, upgrading the primary region, and then re-adding the secondary regions.

2. Upgrade Prechecks: Aurora runs prechecks before initiating the upgrade process. These prechecks might be failing in the us-west-2 cluster. Common issues that cause precheck failures include:

   • Schema inconsistencies
   • Orphaned FULLTEXT indexes
   • Objects with reserved keywords
   • Tables with invalid characters in column definitions

3. XA Transactions: If there are any XA transactions in the prepared state, they need to be committed or rolled back before the upgrade can proceed.

4. Large Number of Tables: If your cluster has a substantial number of tables, it can extend the duration of the precheck and upgrade process. Consider reviewing and eliminating unused tables.

5. High Number of Undo Records: A high number of undo records can result in a long upgrade time. Check the RollbackSegmentHistoryListLength (HLL) metric and consider performing the upgrade when this value is low.

6. Large Ongoing Write Transactions: If there are large transactions with many uncommitted changes, they can cause prolonged upgrades.

7. Long-running or Uncommitted Idle Transactions: These can block the upgrade prechecks and cause failures.

To resolve this issue:

1. Check the Aurora logs for any specific error messages related to the upgrade failure.
2. Run the upgrade prechecks manually if possible to identify any issues.
3. Address any of the above-mentioned problems if they are present in your us-west-2 cluster.
4. If you're dealing with a global database, ensure you're following the correct upgrade process for global clusters.
5. Consider contacting AWS Support if you continue to face issues, as they can provide more targeted assistance based on your specific cluster configuration and any error messages you're receiving.

Remember, it's crucial to upgrade your Aurora MySQL version 2 clusters to version 3 before the end of standard support on October 31, 2024, to take advantage of new features and optimizations.
Sources
Upgrading Aurora MySQL by modifying the engine version - Amazon Aurora
Amazon Aurora MySQL version 2 (with MySQL 5.7 compatibility) to version 3 (with MySQL 8.0 compatibility) upgrade checklist, Part 2 | AWS Database Blog
Amazon Aurora MySQL version 2 (with MySQL 5.7 compatibility) to version 3 (with MySQL 8.0 compatibility) upgrade checklist, Part 1 | AWS Database Blog