AWS-S3 (Simple Storage Service)

• S3 is one of the first services that has been produced by aws.

• S3 is a safe place to store the files.

• It is Object-based storage, i.e., you can store the images, word files, pdf files, etc.

• The files which are stored in S3 can be from 0 Bytes to 5 TB.

• It has unlimited storage means that you can store the data as much you want.

• S3 is a universal namespace,

Buckets

• A bucket is a container used for storing the objects.

• Every object is incorporated in a bucket.

• A bucket has no limit to the amount of objects that it can store. No bucket can exist inside of other buckets.

• S3 performance remains the same regardless of how many buckets have been created.

• The AWS user that creates a bucket owns it, and no other AWS user cannot own it. Therefore, we can say that the ownership of a bucket is not transferrable.

• The AWS account that creates a bucket can delete a bucket, but no other AWS user can delete the bucket.

Objects

• Objects are the entities which are stored in an S3 bucket.

• An object consists of object data and metadata where metadata is a set of name-value pair that describes the data.

• An object consists of some default metadata such as date last modified, and standard HTTP metadata, such as Content type. Custom metadata can also be specified at the time of storing an object.

• It is uniquely identified within a bucket by key and version ID.

Key

• A key is a unique identifier for an object.

• Every object in a bucket is associated with one key.

• An object can be uniquely identified by using a combination of bucket name, the key, and optionally version ID.

Regions

• You can choose a geographical region in which you want to store the buckets that you have created.

• A region is chosen in such a way that it optimizes the latency, minimize costs or address regulatory requirements.

• Objects will not leave the region unless you explicitly transfer the objects to another region.

Data Consistency Model

• Amazon S3 replicates the data to multiple servers to achieve high availability.

• Read-after-write consistency for PUTS of new objects.

• Eventual consistency for overwrite PUTS and DELETES.