Having trouble with flask-SocketIO and eventlet
Eventlet uses cooperative multitasking, which means that you cannot have a task using the CPU for long periods of time, as this prevents other tasks from running.
In general it is a bad idea to include CPU heavy tasks in an eventlet process, so one possible solution would be to offload the CPU heavy work to an external process, maybe through Celery or RQ. Another option that sometimes works (but not always) is to add calls to socketio.sleep(0) inside your CPU heavy task as frequently as possible. The sleep call interrupts the function for a moment and allows other functions waiting for the CPU to run.