Right-sizing
- Definition
- Matching provisioned resource size and type to actual measured workload requirements — continuously, not once.
- The single highest-impact cost optimization action for most organizations.
- What it involves
- Downsize over-provisioned instances; move to a newer or Arm-based (Graviton) family for better price-performance.
- Delete idle resources: unattached EBS volumes, unassociated Elastic IPs, idle load balancers, old snapshots.
- Move storage to the right class with lifecycle policies.
- Tooling
- AWS Compute Optimizer — ML-driven recommendations with a specific target instance type.
- AWS Cost Explorer right-sizing reports.
- AWS Trusted Advisor idle and underutilized resource checks.
- Amazon CloudWatch for the underlying utilization data (install the agent for memory metrics).
- Sequence that matters
- Rightsize before buying Reserved Instances or Savings Plans — otherwise you commit to paying for capacity you did not need.