[Django]-Django/Celery: celeryd won't retrieve new tasks from queue unless restarted

After spending several hours on this, I found an answer in the Celery FAQ:

MySQL is throwing deadlock errors, what can I do?

I wasn’t seeing the deadlock errors in the log, but modifying my /etc/my.cnf to include:

[mysqld]
transaction-isolation = READ-COMMITTED

resolved my issue.

Hope this helps someone else!