Amazon S3 – Consider Deleting or Moving Non-Current Object Versions

Amazon S3 versioning can inadvertently lead to significant cloud storage costs. Non-current object versions continue to consume storage space and incur charges, even when they’re no longer actively used. This policy provides guidance on managing these unnecessary object versions to optimize cloud spending and storage efficiency.

Detailed Explanation

Why This Policy Matters

Object versioning in Amazon S3 is a powerful feature that protects against accidental deletions and provides historical data tracking. However, it can also create hidden cost challenges:

• Each version of an object consumes storage space
• Non-current versions continue to incur storage charges
• Legacy versions can accumulate over time, increasing expenses

Cost Reduction Potential

Implementing an object version management strategy can deliver substantial cost savings:

• Typical Savings: 20-40% reduction in S3 storage costs
• Example Scenario:
  • 100 TB of S3 data with multiple versions
  • Current storage cost: $2,300/month
  • After version cleanup: Potential savings of $460-$920 monthly

Potential Savings Calculation

Total Storage Cost = (Current Version Cost) + (Non-Current Version Cost)

Potential Savings = Non-Current Version Cost × (0.2 - 0.4)

Implementation Guide

Infrastructure as Code Example (Terraform)

resource "aws_s3_bucket" "example" {
  bucket = "my-cost-optimized-bucket"

  versioning {
    enabled = true
  }

  lifecycle_rule {
    enabled = true

    noncurrent_version_expiration {
      days = 30  # Delete non-current versions after 30 days
    }

    noncurrent_version_transition {
      days          = 15
      storage_class = "STANDARD_IA"  # Move to cheaper storage after 15 days
    }
  }
}

Step-by-Step Manual Implementation

1. Review existing S3 bucket configurations
2. Assess current version retention needs
3. Configure lifecycle rules
4. Test and validate configuration
5. Monitor storage costs

Best Practices

• Retention Period: Align with compliance requirements
• Storage Tiering: Use STANDARD_IA or GLACIER for older versions
• Regular Audits: Quarterly version management reviews

Recommended Tools

• AWS S3 Inventory
• AWS Cost Explorer
• Infracost: Helps prevent and identify cost optimization opportunities before deployment

Example Scenarios

Scenario 1: Development Artifact Storage

• Before: 500 GB of accumulated version data
• After: Reduced to 100 GB through intelligent lifecycle management
• Monthly Savings: Approximately $150

Scenario 2: Media Asset Archiving

• Before: Unmanaged video project versions
• After: Automated transition to Glacier storage
• Annual Savings: Up to $3,000

Considerations and Caveats

• Compliance Requirements: Verify data retention policies
• Critical Data: Ensure no accidental deletion of important versions
• Performance Impact: Minimal, but test thoroughly
• Complexity: Requires careful configuration

Frequently Asked Questions (FAQs)