Question

A developer configures an S3 bucket to invoke a Lambda function asynchronously when new objects are uploaded. Occasionally the function fails to process an object even after all automatic retries are exhausted, and those failed events are silently lost. The developer needs to capture the details of these permanently failed asynchronous invocations for later inspection and reprocessing, with minimal code changes. What is the MOST appropriate solution?

Accepted Answer

Configure a dead-letter queue (an SQS queue or SNS topic) on the Lambda function's asynchronous invocation settings to capture events that fail all retry attempts.

Answer

Wrap the entire handler in a try/catch block and write the event payload to a DynamoDB table whenever an exception is thrown.

Answer

Enable an event source mapping between the S3 bucket and the Lambda function so failed batches are retried from the S3 event stream.

Answer

Increase the function timeout and memory so that the function has enough resources to complete before the retries are exhausted.