Troubleshooting and Common Pitfalls

This document outlines some of the common pitfalls you may encounter when getting set up with huey. It is arranged in a problem/solution format.

Tasks not running

First step is to increase logging verbosity by running the consumer with --verbose. You can also specify a logfile using the --logfile option.

Check for any exceptions. The most common cause of tasks not running is that they are not being loaded, in which case you will see QueueException “XXX not found in TaskRegistry” errors.

“QueueException: XXX not found in TaskRegistry” in log file

Exception occurs when a task is called by a task producer, but is not imported by the consumer. To fix this, ensure that by loading the Huey object, you also import any decorated functions as well.

For more information on how tasks are imported, see the docs

“Error importing XXX” when starting consumer

This error message occurs when the module containing the configuration specified cannot be loaded (not on the pythonpath, mistyped, etc). One quick way to check is to open up a python shell and try to import the configuration.

Example syntax: huey_consumer.py main_module.huey

Tasks not returning results

Ensure that you have not accidentally specified result_store=False when instantiating your Huey object.

Scheduled tasks are not being run at the correct time

Check the time on the server the consumer is running on - if different from the producer this may cause problems. By default all local times are converted to UTC when calling .schedule(), and the consumer itself runs in UTC.

Cronjobs are not being run

The consumer and scheduler run in UTC by default. To run the consumer using the server’s localtime, specify --localtime or -o when running the consumer.

Greenlet workers seem stuck

If you wish to use the Greenlet worker type, you need to be sure to monkeypatch in your application’s entrypoint. At the top of your main module, you can add the following code: from gevent import monkey; monkey.patch_all(). Furthermore, if your tasks are CPU-bound, gevent can appear to lock up because it only supports cooperative multi-tasking (as opposed to pre-emptive multi-tasking when using threads). For Django, it is necessary to apply the patch inside the manage.py script. See the Django docs section for the code.

Testing projects using Huey

If you don’t have, or want, a redis server for running tests you can set always_eager to True at your Huey settings.