Day 17 - S3 Advanced Features

Date: 2025-09-30 (Tuesday)
Status: “Done”

Lecture Notes

Amazon S3 Static Website Hosting

Host static websites (HTML, CSS, JS, images) directly from S3.

Key Capabilities

  • Simple setup: A few steps to enable static website hosting on a bucket.
  • Low cost: Pay standard S3 storage and data transfer; no separate web server charges.
  • Elastic scaling: Automatically handles traffic spikes.
  • CDN integration: Easily front with Amazon CloudFront for global performance.

Static Website Configuration:

{
  "IndexDocument": {
    "Suffix": "index.html"
  },
  "ErrorDocument": {
    "Key": "error.html"
  }
}

Cross-Origin Resource Sharing (CORS)

CORS allows web resources (fonts, JavaScript, etc.) on one domain to request resources from another domain.

Configuring CORS on S3

  • Define policies: Specify which origins are permitted to access a bucket’s content.
  • Control methods: Allow specific HTTP methods (GET, PUT, POST, etc.).
  • Security posture: Prevent unauthorized cross-origin access.

CORS Configuration Example:

[
  {
    "AllowedHeaders": ["*"],
    "AllowedMethods": ["GET", "HEAD"],
    "AllowedOrigins": ["https://example.com"],
    "ExposeHeaders": ["ETag"],
    "MaxAgeSeconds": 3000
  }
]

Performance and Object Key Design

Object key naming can significantly affect S3 performance:

  • Randomized prefixes: Distribute keys across partitions for higher parallelism.
  • Avoid sequential prefixes: Don’t use monotonically increasing prefixes (e.g., timestamps) for high-throughput workloads.
  • Parallel access: Structure keys to enable concurrent reads/writes.

Key Design Best Practices:

❌ Bad:  2025-09-30-file1.jpg, 2025-09-30-file2.jpg
✅ Good: a1b2/2025-09-30-file1.jpg, c3d4/2025-09-30-file2.jpg

S3 Glacier – Long-Term Archival

S3 Glacier classes are optimized for ultra–low-cost long-term storage.

Retrieval Options

  • Expedited / Fast: Minutes; highest cost.
  • Standard: 3–5 hours; balanced cost.
  • Bulk: 5–12 hours; lowest cost for large restores.

Glacier Deep Archive

The lowest-cost class for multi-year retention, with ~12-hour retrieval times.

Hands-On Labs

Lab 57 – Amazon S3 & CloudFront (Part 2)

  1. Configure Public Objects → 57-5
  2. Test Website → 57-6
  3. Block All Public Access → 57-7.1
  4. Configure CloudFront → 57-7.2
  5. Test CloudFront → 57-7.3
  6. Bucket Versioning → 57-8