What is AWS S3?

Amazon S3 Concepts

Bucket

Bucket naming rules

Objects

Object Key

Regions

S3 Consistency Model

Amazon s3 provides high availability by storing multiple copies of your data across different availability zone within your data center for each successful create file operation.

Two types of model:

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

Suppose, when you initiate a new object creation or upload process in s3 bucket, as soon as the file creation is completed then you would be able to read the object. Same as, when you PUT an object, as soon as you get a successful response, you would be able to get that object.

When a write operation initiates, it does not wait for all six copies (N.Virginia) to be replicated across all availability zone. As soon as its uploaded in any one of the AZ, you would be able to read the object which is more consistent.

let's say you have an object with some content and you initiated the overwrite PUTS again with the same object name but some modification to the original object content, then it usually takes some time to propagate the object to get copied across all AZ’s in your region by replacing the existing objects with new one and in between this propagation, if you try to read the object, then there are chances that you may find the existing or new object. As per this consistency model, you would be able to read the actual object only after object copy is entirely copied across all AZ’s.

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