Design S3 Lifecycle Policies to automatically transition objects between storage classes and delete expired data for maximum cost efficiency.
S3 Lifecycle Policies — Automate Storage Cost Reduction
S3 Lifecycle Policies automatically transition objects to cheaper storage classes or delete them after a specified period. Without lifecycle policies, old files accumulate in expensive Standard storage forever.
Teacher Note: Lifecycle Policies are like automatic filing rules for your digital storage. After 30 days, move emails from inbox to archive. After 1 year, delete archived emails. Same principle: after 30 days, move S3 files to cheaper storage. After 7 years, delete them.
Lifecycle Transition Timeline
Day 0: Object created in S3 Standard ($0.023/GB)
Day 30: Move to Standard-IA ($0.0125/GB) -- 46% savings
[Minimum 30-day stay required before transitioning to IA]
Day 90: Move to Intelligent-Tiering or Glacier Instant
[Minimum 90-day stay in IA before moving to Glacier Instant]
Day 180: Move to Glacier Flexible ($0.0036/GB) -- 84% savings
Day 365: Move to Glacier Deep Archive ($0.00099/GB) -- 96% savings
Day 2555: Delete (7 years = compliance requirement met)
Common Lifecycle Policy Examples
| Use Case | Policy |
|---|
| Application logs | Standard (30d) → Standard-IA (60d) → Glacier (90d) → Delete (365d) |
| Database backups | Standard (7d) → Standard-IA (30d) → Glacier (90d) → Delete (2555d) |
| User uploads | Standard forever (active content — no lifecycle) |
| Compliance archives | Standard (1d) → Glacier Deep Archive → never delete (7+ years) |
Lifecycle Policy Pitfalls
- Minimum storage duration: Standard-IA and One Zone-IA have 30-day minimum — deleting before 30 days still charges 30 days
- Glacier Flexible has 90-day minimum — charged for full 90 days even if deleted earlier
- Glacier Deep Archive has 180-day minimum
- Transition from Standard to Standard-IA: objects must be at least 128KB (smaller objects are not cost-effective to transition)
Exam Tip: Lifecycle Policies are automatic and cost nothing to configure. They are one of the easiest ways to reduce S3 costs — often 60-80% savings on log data. Always implement lifecycle policies on log buckets, backup buckets, and any bucket storing time-sensitive data.