Explanation
Why the waste happens and who it affects.
These instances may be remnants of retired applications, paused development environments, or workloads that were migrated elsewhere. If an instance shows no active connections and sustained inactivity across CPU and memory metrics, it is likely idle and generating unnecessary costs.
Billing model
The pricing dimensions that drive this cost.
RDS instances are billed based on the selected instance class (vCPU and memory), per second with a 10-minute minimum after a billable status change, while running. Additional charges may apply for storage, backup retention, Multi-AZ replication, and provisioned IOPS-regardless of workload activity.
How to detect
5 checks to find it in your estate.
- Identify RDS instances that have been running continuously during the lookback period
- Review performance metrics to confirm low or zero CPU and memory usage
- Check connection logs and query metrics to validate the absence of active database traffic
- Confirm with owners or application teams whether the instance is still in use
- Evaluate whether snapshots or backups exist that could support future recovery needs
How to fix
How to remove the waste.
Delete the inactive instance after validating that it is no longer required, taking a final snapshot if data retention is necessary. Stopping the instance only suits short pauses: RDS automatically starts a stopped instance after 7 consecutive days, and provisioned storage and backups are still billed while it is stopped. Review and remove associated resources such as storage, backups, or read replicas to fully eliminate residual costs.
Documentation
Vendor references for pricing and configuration.