Dead Letter Queue

This is going to be a very short introduction to dead letter queues.

What is a dead letter queue??

• Dead letter queues are messages queues specifically deployed to holding messages that could not be delivered to their intended queues.

• Messages sometimes fail to get delivered to their intended queues as they might be unavailable or the queue is full.

• Popular message queue tools that support or do not support DLQ:

  • AWS SQS (Simple Queue Service) supports DLQ.
  • RabbitMQ (free and open source) also supports DLQ.
  • Redis does not support DLQ.

Thanks for reading :)
DLQ is a very important component of a scalable and resilient software architecture. This article only provides an introduction to the concept and helps readers with useful links.

Following are some of the useful resources that give more indepth information.

1. https://aws.amazon.com/about-aws/whats-new/2021/12/amazon-sqs-dead-letter-queue-management-experience-queues/

2. https://github.com/antirez/disque#dead-letter-queue

3. https://stackoverflow.com/questions/13824879/how-to-resend-from-dead-letter-queue-using-redis-mq

I request the readers of this post to kindly add more helpful URLs in the comment section, or add your experiences using a DLQ in a real world project. I believe that would help beginners get even better idea about how to use this in their projects.

Thank You
Aniketh Deshpande