How does the uwsgi spooler work?

Reference: http://uwsgi-docs.readthedocs.org/en/latest/Spooler.html

each spooler is a different process aimed at running tasks enqueued in the form of files in a directory (the spool directory). Multiple spooler processes (per uWSGI-instance) can sit on the same spool dir to parallelize task-groups and multiple spooldirs can be configured (to have different task groups)

The spooler approach is very low-level, but requires zero-maintainance (and eventually removing tasks is a matter of rm'ing a file) and it is really solid.

The only alternative (and very probably the most used one) in the python world i am aware of is celery

http://www.celeryproject.org/

otherwise you can rely on the venerable redis + daemon thread approach, where a python thread consumes tasks enqueued in redis. Eventually you can use a uWSGI mule (it is like a worker but without external access) instead of a thread to consume tasks.