Celery is brittle. If you stop a celery service, odds are, it will either not stop at all or leave stray child processes running. It is not transactional, at l

Celery is brittle. If you stop a celery service, odds are, it will either not stop at all or leave stray child processes running. It is not transactional, at least not with a MongoDB back-end. If you stop a celery service, any tasks that were in progress may or may not complete, but none of them will be picked up again when you resume. No prioritization of queues or tasks. It is possible to set up separate services that handle different queues, but that's a PITA and there's still no guaranteed order of processing.