Is your feature request related to a problem? Please describe.

Until now, we used a poison pill pattern to stop workers. It is used with a blocking queue. So it is 1:1, if we have 2 workers, one worker will get the poison pill and exit, the other won't have the pill and will stay alive.

Describe the solution you'd like

We implemented a WORKER_QUEUE with AMQP for sending 1:n events (fanout/pubsub mode) from TaskManager to workers. We used it for cancelling tasks.

We could implement a similar message STOP or SHUTDOWN that would stop all workers.

It would replace the POISON objects that are used to exit the task loop.