S3

Overview

• Amazon S3 has a simple web services interface that you can use to store and retrieve any amount of data, at any time, from anywhere on the web.

• It uses the same highly scalable, reliable, fast, inexpensive data storage infrastructure that Amazon uses to run its own global network of web sites.

Buckets

• A bucket is a container for objects stored in Amazon S3.

• Every object is contained in a bucket.

• They must have a globally unique name and the name must follow the naming convection.

• You can configure buckets so that they are created in a specific AWS Region.

• You can also configure a bucket so that every time an object is added to it, Amazon S3 generates a unique version ID and assigns it to the object.

Objects

• Objects are the fundamental entities stored in Amazon S3.

• Objects consist of object data and metadata.

• Objects can range in size from a minimum of 0 bytes to a maximum of 5 terabytes.

• The data portion is opaque to Amazon S3.

• The metadata is a set of name-value pairs that describe the object.

  • These include some default metadata, such as the date last modified, and standard HTTP metadata.

Keys

• A key is the unique identifier for an object within a bucket.

• Every object in a bucket has exactly one key.

• The combination of a bucket, key, and version ID uniquely identify each object.

Object Versioning

• Use Amazon S3 Versioning to keep multiple versions of an object in one bucket.

• It is defined at the bucket level; not at the object level.

• For example, you could store my-image.jpg (version 111111) and my-image.jpg (version 222222) in a single bucket.

• S3 Versioning protects you from the consequences of unintended overwrites and deletions.

• You can also use it to archive objects so that you have access to previous versions.

• You must explicitly enable S3 Versioning on your bucket.

  • By default, S3 Versioning is disabled.

• If S3 Versioning is enabled, Amazon S3 assigns a version ID value for the object.

Uploading objects using multipart upload API

• Multipart upload allows you to upload a single object as a set of parts.

• Each part is a contiguous portion of the object's data.

  • You can upload these object parts independently and in any order.

• If transmission of any part fails, you can retransmit that part without affecting other parts.