Poison Message
A record that deterministically fails processing because of its content, schema, or business state and can block normal consumption if retried indefinitely.
Unlike a transient infrastructure failure, a poison message fails again under the same consumer version and input. Unlimited retries can let one record monopolize a worker, block a partition, or prevent queue progress for much longer than the original fault deserves.
The system should distinguish deterministic data failure from transient dependency failure, isolate the record when needed, and replay it only after the root cause is corrected. Safe retry design in critical systems explains why these failure classes need different retry policies.