Question

A company runs an order-processing pipeline where an Amazon SQS standard queue triggers an AWS Lambda function that writes records to a downstream API. Occasionally a malformed message causes the Lambda function to throw an exception. Because the message stays on the queue, Lambda repeatedly retries it, blocking healthy messages behind it and driving up invocation costs. Operations staff also have no visibility into which messages are failing. The team wants to improve the reliability and observability of the pipeline with minimal custom code. What should the solutions architect recommend?

Accepted Answer

Configure a dead-letter queue on the source SQS queue with a maxReceiveCount, and set up a CloudWatch alarm on the DLQ's ApproximateNumberOfMessagesVisible metric so failed messages can be inspected and redriven.

Answer

Increase the Lambda function timeout and the SQS visibility timeout so the function has more time to successfully process each message before it becomes visible again.

Answer

Switch the standard queue to a FIFO queue with content-based deduplication so that malformed messages are automatically discarded after the first failure.

Answer

Enable Lambda provisioned concurrency and add a try/catch block that silently drops any message that throws an exception to prevent blocking the queue.