Final answer:
Read after Write consistency guarantees that as soon as data is written, it can be immediately read, which is important for data accuracy post-write operations. In Amazon S3, it applies to new object PUT operations, ensuring instant data retrieval after a new object is stored.
Step-by-step explanation:
What is Read after Write Consistency?
Read after Write consistency is a concept used in distributed systems, especially in cloud storage services, which ensures that once a new object is written (or an existing object is updated), it is immediately readable. This is vital for scenarios where accurate and up-to-date data retrieval is critical immediately after the data write has occurred.
In the context of Amazon S3 (Simple Storage Service), Read after Write consistency applies to PUTS of new objects. Meaning that as soon as a new object is created (PUT operation), it can be retrieved (GET operation) instantly with the assurance that the most recent write is what will be read.
Application in Amazon S3
Amazon S3 assures Read after Write consistency for PUTS of new objects and for DELETES. However, it's worth noting that this consistency model does not apply to overwriting PUTS and DELETES on existing objects, where eventual consistency is used.
Therefore, immediately after a new file is uploaded to S3, you can access this file, whereas if you update or delete an existing file, there might be a brief interval before the change is propagated and consistently seen by all subsequent read operations.