How do I resolve a preupgrade check failure in Amazon RDS for MySQL?

Short description

If your DB instance experiences a preupgrade check failure, then your Amazon RDS for MySQL version upgrade is stopped. When incompatibilities are detected, Amazon RDS provides a log file for you to review the details of the failed precheck.

Note: There are different prechecks that are built into the MySQL database and Amazon RDS. Also, prechecks aren't run for upgrades for versions lower than MySQL 5.7. For upgrades from MySQL 5.6 to MySQL 5.7, prechecks are limited to detecting orphan tables and sufficient storage space to rebuild tables.

Resolution

When you perform an upgrade from MySQL 5.6.x to 5.7.x, or from MySQL 5.7.x to 8.0.x, Amazon RDS automatically runs prechecks. The prechecks detect any data incompatibilities that might affect your upgrade. Prechecks are designed to minimize any unplanned downtime during a version upgrade.

If you experience a preupgrade check failure during one of these version upgrades, review the PrePatchCompatibility log file generated by Amazon RDS. You can view the PrePatchCompatibility log file under Logs & eventsin the Amazon RDS console. Then, review the details of the listed incompatibility issues and correct the issue. In most cases, the log entry will include a link to the Amazon RDS for MySQL documentation on how to correct the incompatibility.

Tip: It's a best practice to test your DB instance before a major version upgrade.