The Simple Pirate Queue pattern works pretty well, especially because it's just a combination of two existing patterns. Still, it does have some weaknesses: It's not robust in the face of a queue crash and restart. The client will recover, but the workers won't. While ZeroMQ will reconnect workers' sockets automatically, as far as the newly started queue is concerned, the workers haven't signaled ready, so don't exist. To fix this, we have to do heartbeating from queue to worker so that the worker can detect when the queue has gone away. The queue does not detect worker failure, so if a worker dies while idle, the queue can't remove it from its worker queue until the queue sends it a request. The client waits and retries for nothing. It's not a critical problem, but it's not nice. To make this work properly, we do heartbeating from worker to queue, so that the queue can detect a lost worker at any stage.
Implement the Robust Reliable Queuing (Paranoid Pirate Pattern) example.