We are trying to figure out how these two settings interplay in: [DEFAULT]/workers [taskflow_executor]/max_workers [oslo_messaging_zmq]/rpc_thread_pool_size Just setting workers makes a bit of sense, and based on our testing: =0 creates one process =1 creates 1 plus 1 child =n creates 1 plus n children Are there green threads (i.e. coroutines, per https://eventlet.net/doc/basic_usage.html) within every process, regardless of the value of workers? Does max_workers affect that? We have read some Glance doco, hunted about various bug reports[1] and other discussions online to get some insight, but I think we're not clear on it. Can anyone explain this a bit better to me? This is all in Rocky. Thank you, Greg. [1] https://bugs.launchpad.net/glance/+bug/1748916