Dead-letter queue
A separate queue for messages that were not processed successfully under the system's retry policy, so they can be reviewed and handled.
On this page
Source content checked . English translation published 2026-10-27.
In business automation
The queue separates exceptions from routine work. It is useful only when there is monitoring, ownership, and a process for returning a message to processing after a fix, without duplicating an action that already succeeded.
Examples
These examples illustrate a possible workflow. Adapt the connections and rules to your own systems.
Business process example
An order event repeatedly fails because a product code is missing. It is moved to an exception queue with the reason and order ID. After the mapping is fixed, it is returned to processing in a controlled manner.
Relevant tools
- n8n
- You can connect a workflow to a queue service or build a persistent exception queue; this is not an automatic built-in queue for every node.
What to check
- Do not let the queue become a forgotten storehouse. Set an alert, retention period, and check for effects that already occurred before the failure.