What is Simple Storage Service (S3) in AWS? [Part-2]

S3 Bucket Versioning

• Bucket Versioning is an S3 Bucket sub-resource used to protect against accidental object/data deletion or overwrites.

• Versioning can also be used for data retention and archiving.

• Once you enable versioning on a bucket, it cannot be disabled, however, it can be suspended.

• When enabled, bucket versioning will protect existing and new objects and maintains their versions as they are updated.

• Updating objects refers to PUT, POST, COPY, and DELETE actions on objects.

• When versioning is enabled, and you try to delete an object, a delete marker is placed on the object.

  - You can still view the object and the delete marker.

• If you reconsider deleting the objects you can delete the "Delete Marker" and the object will be available again.

• You will be charged for all S3 storage costs for all object versions stored.

• You can use Versioning with S3 Lifecycle policies to delete older versions, or you can move them to a cheaper S3 storage (or Glacier)

• There are 3 Bucket Versioning State

  - Enable

  - Suspended

  - Un-versioned

• Once you enable the S3 bucket the un-versioned gets removed.

• Versioning applies to all objects in a bucket and is not partially applied.

• Object existing before enabling versioning will have a version ID or NULL.

• If you have a bucket that is already versioned, then you suspend versioning, existing objects and their versions remain as it is.

  - However, they will not be updated/versioned further with future updates while the bucket versioning is suspended.

• New objects (uploaded after suspension) will have a Version ID "NULL" if the same key (name) is used to store another object, it will override the existing one.

  An object deletion in a suspended versioning bucket will only delete the objects with ID "NULL".

MFA Delete in S3

Multifactor Authentication delete is a Versioning capacity that adds another level of security in case your account is compromised.

This adds another layer of security for the following

• Changing your Bucket's versioning state.

• Permanently deleting an object version.

MFA Delete Requires

• Your security credentials

• The code is displayed on an approved physical or software-based authentication device.

S3 Multipart Upload

• It is used to upload an object in parts.

• Parts are uploaded independently and in parallel, in any order.

• It is recommended for object sizes of 100MB or larger.

• You must use it for objects larger than 5GB.

• This is done through S3 multipart upload API.

Copying S3 Objects

• The Copy operation creates a copy of an object that is already stored in Amazon S3.

• You can create a copy of your object up to 5GB in size for a Single atomic operation.

• However, to copy an object greater than 5GB, you must use the multipart upload API.

• Incur charges, if copied to another region.

One can use the Copy Operation to

• Generate additional copies of the Subject.

• Renaming object (copy to a new name)

• Changing the copy's storage class or encrypting it at rest.

• Move object across AWS location Region.

• Change Object Metadata.