Have the worker use a process pool

[kureuil]

When the worker receives a job from the broker, it spawns a brand new process per job. While this is easy to implement and monitor, it is sub-optimal on the performance side.

One possible solution to this performance problem would be to have a pool of processes, which are kept alive as long as possible. The main worker process would send over to these "worker worker" processes the jobs to execute, and they would send a message back to acknowledge or reject the job execution. If one the processes dies, it should be restarted and the job should be sent back to the broker as "rejected".