Amazon S3

Size of the files on S3?

From 0 Bytes to 5 TB

What is the data consistency model for S3?

• Read after Write consistency for PUTS of new Objects
• Eventual Consistency for overwrite PUTS and DELETES (can take some time to propagate)

S3 is object based. What do objects consist of?

• key (This is the name of the object)
• value (This is the data and is made up of a sequence of bytes)
• version ID (very important for versioning)
• metadata (data about data you are storing)

What are the different Tiers/Classes of storage for S3?

• S3 Standard : 99.99% availability, 99.999999999% durability, stored redundantly across multiple devices in multiple facilities, and is
  designed to sustain the loss of 2 facilities concurrently. No retrieval fees
• S3 – IA (Infrequently Accessed) : For data that is accessed less frequently, but requires rapid access when needed. Lower fee than S3, but you are charged a retrieval fee.
• S3 One Zone – IA : want a lower cost option for infrequently accessed data, but do not require the multiple AZ data resilience.
• Glacier : Very cheap, but used for archival only. Expedited (higher fees less retrieval time — within minutes),
  Standard (3-5 hours) or Bulk (5-12 hours).

S3 Charges?

Charged for

• Storage
• Requests
• Data Transfer Pricing (when you transfer data from one region to another)
• Transfer Acceleration

What is S3 Transfer Acceleration?

Amazon S3 Transfer Acceleration enables fast, easy, and secure transfer of files over long distances between your end users and an S3 bucket.

Transfer Acceleration takes advantage of Amazon CloudFront’s globally distributed edge locations. As the data arrives at an edge location, data
is routed to Amazon S3 over an optimized path.

What are the Server Side Encryption options for S3?

• SSE with Amazon S3 Managed Keys (SSE-S3)
• SSE with KMS (SSE-KMS)
• SSE with Customer Provided Keys (SSE-C)

What are the two options for controlling access to a S3 bucket?

• Bucket ACL
• Bucket Policies

S3 Versioning characteristics?

• Stores all versions of an object (including all writes and even if you delete an object)
• Great backup tool
• Once enabled, versioning cannot be disabled, only suspended
• Integrates with Lifecycles rules
• Versioning’s MFA Delete capability, which uses multi-factor authentication, can be used to provide an additional layer of security.

Cross replication on S3?

• Versioning must be enabled on both the source and destination buckets
• Regions must be unique
• Files in an existing bucket are not replicated automatically. All subsequent updated files will be replicated automatically.
• You cannot replicate to multiple buckets or use daisy chaining (at this time)
• Delete markers are replicated
• Deleting individual versions or delete markers will not be replicated

Lifecycle Management in S3?

• Can be used in conjunction with versioning
• Can be applied to current versions and previous versions
• Following actions can now be done:
  • Transition to the Standard IA storage class
  • Archive to Glacier Storage Class
  • Permanently Delete