Non-production RDS databases keeping automated backups for more than 7 days
What does ZopNight detect here?
ZopNight reads `BackupRetentionPeriod` on dev and test RDS instances and singles out those above 7 days. Extra retention days add backup storage that Amazon RDS bills once it passes the free allowance, but ZopNight cannot yet measure that billable excess per database, so no finding or dollar figure appears until it can.
Signal and threshold
| Field | Value |
|---|---|
| Rule IDs | RC-032 |
| Category | rightsizing |
| Severity | low |
| Metric | none — pure configuration read |
| Threshold | BackupRetentionPeriod > 7 days on a dev/test database |
| Source | ZopNight |
| Permissions used | rds:DescribeDBInstances · rds:DescribeDBSnapshots |
Where it applies
Where the backup bill comes from
Amazon RDS keeps automated backups for the retention period you set, from 0 to 35 days per the retention period docs. The CLI and API default is 1 day, while the console default is 7. Longer retention means more backup storage, and the RDS for MySQL pricing page explains the allowance: there is no additional charge for backup storage up to 100% of your total database storage in a Region. Above that, every extra GB is billed. Manual snapshots count toward the same Regional total.
On a development or QA database, 30 days of point-in-time recovery is rarely needed. A week is usually enough to undo a bad migration.
Listing retention settings yourself
aws rds describe-db-instances \ --query 'DBInstances[?BackupRetentionPeriod > `7`].[DBInstanceIdentifier,BackupRetentionPeriod,AllocatedStorage]' \ --output table
aws rds describe-db-snapshots --snapshot-type manual \ --query 'DBSnapshots[].[DBSnapshotIdentifier,DBInstanceIdentifier,AllocatedStorage]'Compare the Region’s total backup usage on your bill with the sum of AllocatedStorage to see
whether you are past the free allowance at all.
What ZopNight checks
- The database name matches a dev or test pattern and no environment tag says production.
- The retention period RDS reports for the instance is greater than 7 days.
- ZopNight has a monthly cost for the instance.
Why no finding appears today
ZopNight will only show this recommendation with a real dollar figure, and the backup usage data it has today is not accurate enough to produce one. It sums the allocated size of snapshots without netting off the free allowance or separating automated from manual backups, which could overstate the charge many times over. Rather than publish an inflated saving, the rule raises nothing until it can price the billed backup storage for each database. The checks above still run, so the rule is ready once that data is available.
What the saving would be
Reducing retention from, say, 35 to 7 days removes 28 days of automated backups. The saving is the backup storage those days occupy above the free allowance, at the Regional backup storage rate. If the Region is under the allowance, the saving is zero, which is why a flat estimate would be wrong.
Shortening retention on a non-production database
- Check with the owning team that nothing depends on restores older than 7 days.
- Take a manual snapshot first if you want one long-lived restore point; manual snapshots are independent of automated backups and the retention setting does not remove them.
- Apply the change:
aws rds modify-db-instance --db-instance-identifier dev-app-db --backup-retention-period 7 --apply-immediately