Question

A company processes uploaded documents using EC2 worker instances that poll an Amazon SQS standard queue. Each document takes about 4 minutes to process, but the queue's visibility timeout is set to 60 seconds. Operators notice that some documents are being processed multiple times by different workers, creating duplicate output files. Which change will most directly resolve the duplicate processing?

Accepted Answer

Increase the queue's visibility timeout to a value greater than the maximum processing time (for example, 6 minutes).

Answer

Switch the standard queue to a FIFO queue to guarantee each message is delivered exactly once.

Answer

Enable long polling on the queue to reduce the number of empty receive requests.

Answer

Increase the message retention period so messages remain in the queue longer.