Question

A developer builds a serverless image-processing pipeline. A Lambda function uploads a newly generated thumbnail to an Amazon S3 bucket using PutObject, and immediately after the successful PutObject response it issues a GetObject for that same key to verify the upload before returning a response to the caller. The developer is concerned the GetObject might fail or return stale data. What is the correct expectation for this read?

Accepted Answer

The GetObject will return the newly written object because S3 provides strong read-after-write consistency for new object PUTs.

Answer

The GetObject may return a 404 or older data because S3 only offers eventual consistency for all operations, so the code should retry with exponential backoff.

Answer

The read is only consistent if the developer enables S3 Object Lock on the bucket before uploading.

Answer

The read is only consistent if versioning is enabled and the exact version ID is passed to GetObject.