Ref: https://learn.cantrill.io/courses/1820301/lectures/41301484 and https://learn.cantrill.io/courses/1820301/lectures/41301485

• Summary
• Contents:

Overview of S3 Storage and Classes

• 🔧 S3 is quite cheap for the value it provides, but it additionally offers different tiers of storage classes that can save even more costs
  • Different tradeoffs between costs and other features (retrievability speed and costs, data replication…)
• S3 storage characteristics:
  • 11 nines of durability (99.9…9% durability)
    • For 10million objects, expect 1 object loss every 10k years
    • ‼️ When you use S3 PUT operation, if S3 responds with HTTP/1.1 200 OK, then the object has been stored durably in S3!
  • Content-MD5 Checksums & CRCs (Cyclic Redundant Checks) → detect and fix any data corruption
  • Data replication across at least 3 AZs → regional resilience
    • ‼️ Exception: One-Zone Infrequent Access storage class!
  • First-byte latency of milliseconds EXCEPT for archival classes
    • Objects can be made publicly available (e.g. via static website hosting or URLs)
• Billing (assuming no free tier):
  • GB/month fee for data stored (different depending on storage class)
  • $1/GB of data transferred OUT of S3 (data transfer IN is free)
  • Fee per 1k requests
  • Additional billing for different storage classes (see each class for details)
  • Documentation: https://aws.amazon.com/s3/pricing/
• Storage Classes:
  1. Amazon S3 storage classes → “warm” storage
     • S3 Standard
     • S3 Infrequent Access (IA)
     • S3 One-Zone Infrequent Access (1Z-IA)
  2. Amazon S3 Glacier storage classes → “cold” storage → archival purposes
     • S3 Glacier Instant Retrieval (IR)
     • S3 Glacier Flexible Retrieval (FR) = S3 Glacier (old name)
     • S3 Glacier Deep Archive (DA)
  3. Amazon S3 Intelligent Tiering (special class)
  • Documentation: https://aws.amazon.com/s3/storage-classes/

S3 Standard → Default

Diagram: https://github.com/acantril/aws-sa-associate-saac03/blob/main/0700-SIMPLE_STORAGE_SERVICE(S3)/00_LEARNINGAIDS/S3StorageClasses-1.png

• 🔧 Default storage class
  • For frequently-accessed data which is important and NOT replaceable!
• No penalties, no discounts, most balanced class of storage when considering features & compromises
  • No retrieval fee, no minimum storage duration, no minimum object size
  • Normal S3 billing

S3 Standard-Infrequent Access (IA)

Diagram: https://github.com/acantril/aws-sa-associate-saac03/blob/main/0700-SIMPLE_STORAGE_SERVICE(S3)/00_LEARNINGAIDS/S3StorageClasses-2.png

• 🔧 Storage costs ~½ of S3 Standard
  • In exchange: there's retrieval fee, minimum storage duration, and minimum object size
  • For infrequently-accessed data (~1x/month) which is important and NOT replaceable!
• Save costs on storage… but have extra billing:
  • ∃ retrieval fee per GB of data → overall costs increase with frequent data access!
    • ❗ IN ADDITION to transfer fee
  • ∃ minimum duration charge of 30 days
    • Objects can be stored for less time, but charged as if they were stored for 30 days
  • ∃ minimum capacity charge of 128kB per object
    • If objects are smaller, you still pay like if they were 128kB
• 💡 Good choice if you don't access data frequently, you want to store objects long-term, and don't want to store lots of small objects