AWS SQS multiple DLQs

Question

we have currently a sqs queue for processing incoming data. Is there a recommended way for managing two DLQs for one queue?

• if there is a parsing error of the incoming data, then I want to move the message directly into a "userInput" DLQ, without redrives
• if our mongo is on maxConnections, or any other error occurs, then the configured redrive policy should take place

Do I have to put the message manually into the dlq for the first szenario, or is there a better way?

Thanks!

Answer 1

An Amazon SQS queue only has one Dead Letter Queue.

If a message is read from an SQS queue more than a defined number of times, the message can be moved to the Dead Letter Queue for later processing. However, there is no control over what conditions will send the message to the Dead Letter Queue. It is simply based on a message being retrieved more than the maxReceiveCount.

See: Amazon SQS dead-letter queues

Please note that SQS itself does not process the message. Rather, you will have an app or an AWS Lambda function that reads the message from the queue and processes the message. Therefore, you could program your desired functionality (checking incoming data, responding to Mongo maxConnections) into the code that is processing the message from SQS. If it detects such a problem, that program could send the message to a specific queue, and then delete the original message from the source SQS queue.

This would have the same behaviour as having "multiple DLQs", except that your code is responsible for the logic of moving the messages to these queues, rather than Amazon SQS doing it.