Upgrade strategies for Amazon RDS for MySQL 8.0 to 8.4

This article provides comprehensive guidance on upgrading Amazon RDS for MySQL 8.0 to 8.4 before the July 31, 2026 end-of-standard-support deadline.

• MySQL 8.0 reaches end of standard support on July 31, 2026; extended support available for additional cost
• Extended support costs $292-$1,728/month depending on deployment type and instance class
• Key MySQL 8.4 changes: caching_sha2_password replaces mysql_native_password, SOURCE/REPLICA terminology replaces MASTER/SLAVE, InnoDB defaults changed
• RDS runs mandatory prechecks automatically; incompatibilities reported in PrePatchCompatibility.log file
• Three upgrade methods available: in-place upgrade (minutes-hours downtime), Blue/Green deployment (under 5 seconds downtime), snapshot restore (hours downtime)
• Blue/Green deployments recommended for production; offers immediate rollback capability
• Test upgrades on non-production copies using snapshots or read replicas before production
• Upgrade read replicas before primary instance; Multi-AZ standby instances upgraded automatically
• Create new mysql8.4 parameter group; review custom parameters against new defaults
• Monitor CloudWatch metrics and slow query logs post-upgrade; warm database buffer pool before full traffic

Plan MySQL 8.0 to 8.4 upgrades early, test thoroughly, and use Blue/Green deployments for critical production workloads to minimize downtime and risk.