A dead letter queue with an owner

A dead letter queue that nobody owns is a queue where messages go to be forgotten, and ours had 8,000 of them.

the policy that fixed it:

  every queue names an owner in its configuration
  the owner gets a daily message if the DLQ is non-empty
  a message older than 7 days in a DLQ fails the
    weekly report
  the DLQ has a documented replay command

and the first week's clear-out: 8,104 messages, of which
7,900 were one poison message retried by a consumer that
had no backoff.

Owning a dead letter queue means deciding, per message class, whether a failure is replayable or terminal — and the replay command has to exist before that decision can be acted on. The 7,900 duplicates were a separate bug and they are what made the queue unreadable, which is the usual reason these get abandoned.