Usage first
Start with actual load patterns, not just instance class names. The wrong change can raise cost while creating risk.
Insights
RDS rightsizing guide
Database spend often grows quietly. The right rightsizing review looks at real CPU, memory, IOPS, replicas, and failover behavior before making changes.
Replica awareness
Read replicas, Multi-AZ behavior, and failover expectations affect what “right-sized” really means.
Practical outcome
The goal is a smaller bill and a stable system, not a faster migration to a cheaper problem.
Review checklist
What to review before changing RDS
Peak utilization, buffer cache behavior, storage growth, replica requirements, and whether the workload is over-provisioned for its real traffic.
CPU and memory headroom
IOPS and storage type
Replica and failover needs
Peak versus average usage
Cost per environment