Simple Storage Services, S3 provides developers and IT teams with secure, durable, high-scalable object storage.

Amazon S3 is easy to use, with a simple web service interface to store and retrieve any amount of data from anywhere on the web.

S3 is a safe place to store your files. It's Object-based storage.

The data is spread across multiple devices and facilities.

• S3 is Object-based, allows you to upload files. It storage files only, not suitable to install an operating system or database on.
• Files can be from 0 Bytes to 5TB.
• There is unlimited storage, no storage maximum.
• Files are stored in Buckets.
• S3 is a universal namespace. That is, names must be unique globally. Any Bucket we create will have a unique web address.
• Bucket name example: https://s3-eu-west-1.amazonaws.com/acloudguru
• When you upload a file to S3, you will receive a HTTP 200 code if the upload was successful.
• Built for 99.99% availability for the S3 platform.
• Amazon Guarantee 99.9% availability
• Amazon guarantees 99.999999999% durability for S3 information. (Remember 11 x 9s). Amazon 對用戶上傳到 S3 的 file 有極高的保證不會遺失或損毀
• Tiered Storage Available
• Lifecycle Management
• Versioning
• Encryption
• Secure your data using Access Control Lists and Bucket Policies

• Read after Write consistency for PUTS of new Objects.

假設我們有一個新的 file 上傳到 AWS S3，那上傳之後我們便可馬上讀取，稱為 Read after Write

• Eventual Consistency for overwrite PUTS and DELETES (can take some time to propagate)

而當我們已經有了某個 file 而我們要更新或刪除他時，因為 AWS 在全世界有多個 availability zone，會需要花一點時間 (few ms or seconds) 同步，所以在同步期間或有新舊版本的差異

• S3 is Object based. Object consist of following:
  • Key (This is simply the name of the object)
  • Value (This is simply the data and is made up of a sequence of bytes)
  • Version ID (Important for versioning)
  • Metadata (Data about data you are storing)
  • Subresources:
    • Access Control Lists
    • Torrent

• 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.
• 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 Availability Zone data resilience.
• Glacier: Very cheap, but used for archival only. Expedited, Standard or Bulk. An Expedited retrieval time takes a few minutes but the higher fee. A Standard retrieval time takes 3 - 5 hours and Bulk takes 5 - 12 hours.

Charged for:

• Storage
• Requests
• Storage Management Pricing
• Data Transfer Pricing
• Transfer Accelertion

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

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