Definition
A side queue where messages land after repeatedly failing to process, so they don't block or get lost.
How it works
After N failed attempts a poison message is moved to the DLQ for inspection or manual replay, instead of looping forever and stalling the main queue. Essential for at-least-once pipelines; pair it with alerting so failures are noticed.
Common questions
What is Dead Letter Queue?
A side queue where messages land after repeatedly failing to process, so they don't block or get lost.
How does Dead Letter Queue work?
After N failed attempts a poison message is moved to the DLQ for inspection or manual replay, instead of looping forever and stalling the main queue. Essential for at-least-once pipelines; pair it with alerting so failures are noticed.
What is Dead Letter Queue used for in system design?
After N failed attempts a poison message is moved to the DLQ for inspection or manual replay, instead of looping forever and stalling the main queue. Essential for at-least-once pipelines; pair it with alerting so failures are noticed.