1. Check and Confirm Backup Retention

Go to your current "green" DB in the RDS console:

• Under “Maintenance & backups”, check "Backup retention period".

• If it is set to 14 days and the old one was 1 day, this is the cause.

2. Reduce Retention if Acceptable

• If business allows, reduce from 14 days to 3–7 days (or back to 1 if safe).

• This will immediately stop accumulating more snapshot data.

3. Review Snapshots

• Go to RDS → Snapshots, and look at:

  • How many automated backups exist.

  • If there are manual snapshots too (they are also billed).

• Delete old or unnecessary snapshots, especially from the Blue DB (if any linger).

4. Tag and Track

• Use AWS Cost Explorer with resource-level tags to track:

  • Which DB instance or snapshot is contributing to backup charges.

  • This will help identify which backups are costing you.

5. Monitor with AWS Budgets

• Set a budget alert for RDS:ChargedBackupUsage to avoid surprises in future.

🛠 Optional Enhancements

• Enable RDS Lifecycle policies using AWS Backup (more granular control).

• Use RDS storage autoscaling in the future (for better control on provisioned space).

• If using Aurora, check if you're paying for snapshot export to S3 or long-term retention backups.