# RDS Excessive Backup Retention

> Backup retention beyond 7 days on dev/test RDS databases exceeds the non-production ceiling. ZopNight classifies them but permanently abstains from quantifying today: the backup_chargeable_bytes signal sums gross snapshot storage without netting AWS's free allowance, so any dollar figure would overstate the real RDS:ChargedBackupUsage charge.

Source: https://zop.dev/integrations/aws/recommendations/rds-excessive-backup-retention
Updated: 2026-08-19

---

## Reading retention days from discoverer metadata

- resource.Name: dev/test pattern (with prod env-tag as an authoritative veto via isProdEnvTag)
- Metadata["backup_retention_days"] (JSON int, discoverer-stamped from BackupRetentionPeriod, not a Tag, since the prior retentionDaysFromTags read was a dead contract); must be > maxNonProdRetentionDays
- PricingAware: per-resource monthly cost
- Metadata["backup_chargeable_bytes"] (stringified int64): the producer discoverer/internal/provider/aws/rds_backup_enrichment.go does stamp this key on live data (wired as aws-rds-backup, enrichment flag defaults ON), so it is not a producer gap. It is, however, not billing-truth: it sums the gross AllocatedStorage of every DescribeDBSnapshots result (automated and manual) with no netting of [AWS's free backup allowance, which covers 100% of total provisioned DB storage in the region](https://aws.amazon.com/rds/pricing/) and no automated/manual split, so it can overstate the true RDS:ChargedBackupUsage charge by a large, effectively unbounded factor that the cost cap does not meaningfully bound.

## The non-production retention ceiling

```text
maxNonProdRetentionDays=7
```

## Why this rule never puts a dollar figure on it

backupSavings currently always returns "not quantified". The rule permanently abstains on dollar quantification (never fires a recommendation) rather than price off the unreliable backup_chargeable_bytes signal described above, so it never fabricates a cost-driven saving. The rds-snapshot SKU rate plumbing (SetSKURates/TargetSKUCandidates) is retained un-read so a future rebase onto the real billed RDS:ChargedBackupUsage CUR/billing line item (netted against the region free allowance, automated-snapshots-only) only needs to change backupSavings' body. Classification (dev/test name, prod-env veto, retention threshold, pricing presence) still runs but cannot currently produce a recommendation.

## Trimming retention back to 7 days

1. Evaluate if retention > 7 days is needed for this non-production database
2. Go to RDS Console → Modify → Backup retention period
3. Set to 7 days for non-production workloads
4. Consider using manual snapshots for longer retention needs

## No metrics, only the backup storage SKU rate

None (SKURatesAware: rds-snapshot backup-storage SKU rate)