You create an Amazon SQS queue to decouple software components. The messages are processed by a Lambda function. Sometimes, the Lambda function fails to process messages in the queue. You need a mechanism to isolate the message failures to determine why the processing was unsuccessful. Which of the following options would you choose?

Answer options:

A.FIFO (First-In-First-Out) queue
B.Visibility timeout
C.SQS dead-letter queue
D.SQS long polling

Correct Answer – C
SQS dead-letter queue should be selected as it is designed to isolate problematic messages in the queue. For details, please check the link-https://docs.aws.amazon.com/AWSSimpleQueueService/latest/SQSDeveloperGuide/sqs-dead-letter-queues.html.
Option A is incorrect: Because the FIFO queue itself does not isolate the messages that have failures.
Option B is incorrect: Visibility timeout prevents other consumers from processing the message again. It does not resolve the mentioned problem.
Option C is CORRECT: Because users can configure the dead letter queue to isolate the message failures as follows:
Option D is incorrect: SQS long polling reduces the number of empty responses. It cannot handle the problematic messages.