Dead-letter queue
A separate queue that holds messages a consumer cannot process, after a set number of failed attempts. It stops one bad message from blocking the queue, and keeps the message for people to inspect or replay.
Reliability
In Quorum#
A Queue card has a Failed tasks setting: Retry forever or Dead-letter queue, with 1, 3, 10, or 25 attempts. A failed attempt comes back 30 s later and runs on the Worker again; a task that fails every attempt is lost. The Poison message Incident can hit only a Queue that retries forever: a task that always fails keeps coming back, and its Workers spend 90% of their time on it. Turn on the dead-letter queue to make the Queue immune, or delete the message to end the Incident.
Read next#
At-least-once delivery, Retry with backoff and jitter, Idempotency, Backpressure