Best practices for upgrading Amazon RDS for MySQL 8.0 to 8.4 with prechecks, Blue/Green, and rollback

This article provides a comprehensive guide for upgrading Amazon RDS for MySQL 8.0 to 8.4 with minimal downtime and rollback capability.

• MySQL 8.0 standard support ends July 31, 2026; upgrade to 8.4 LTS recommended
• Phase 1: Run MySQL Shell upgrade checker on snapshot to identify compatibility issues before production upgrade
• Phase 2: Use RDS Blue/Green Deployments for minimal downtime (typically 5 seconds or less) during upgrade
• Phase 3: Set up reverse replication for rollback capability using native replication or AWS DMS
• Key compatibility changes include mysql_native_password deprecation and restrict_fk_on_non_standard_key parameter
• Pre-upgrade checks identify errors (blocking), warnings (evaluate), and notices (informational)
• Multiple parameter default values change in MySQL 8.4; review and adjust parameter group accordingly
• Binlog retention must be at least 24 hours to support rollback path setup
• Native replication preferred over AWS DMS for homogeneous MySQL-to-MySQL migration
• Clean up temporary resources after upgrade completion to avoid additional charges

This three-phase approach provides a tested, reversible upgrade path with minimal production impact, reducing risk for major version upgrades.