Files
edx-platform/cms/celery.py
Tim McCormack 0c57a02119 Enforce a Celery singleton across cms and lms by using shared module (#25840)
This should prevent the issues we've seen recently where cms modules are
imported by the running lms process, resulting in two celery instances
being created and tasks intermittently being registered to the wrong
instance (and therefore effectively lost.)

In commit ab6bf348d4/PR #25822 we tried to ensure that only one or the
other of the instances was created by adding a startup check.
Unfortunately, there's an external shared library that refers directly
to the lms celery, causing a startup failure in cms, so we had to revert
it. Rather than waiting to fix that library, this commit collapses
the two instances together so that there is only ever one.
2020-12-10 17:54:31 +00:00

49 lines
1.8 KiB
Python

"""
Import celery, load its settings from the django settings
and auto discover tasks in all installed django apps.
Taken from: https://celery.readthedocs.org/en/latest/django/first-steps-with-django.html
"""
import os
from openedx.core.lib.celery.routers import AlternateEnvironmentRouter
# Set the default Django settings module for the 'celery' program
# and then instantiate the Celery singleton.
os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'cms.envs.production')
from openedx.core.lib.celery import APP # pylint: disable=wrong-import-position,unused-import
# Import after autodiscovery has had a chance to connect to the import_module signal
# so celery doesn't miss any apps getting installed.
from django.conf import settings # pylint: disable=wrong-import-position,wrong-import-order
class Router(AlternateEnvironmentRouter):
"""
An implementation of AlternateEnvironmentRouter, for routing tasks to non-cms queues.
"""
@property
def alternate_env_tasks(self):
"""
Defines alternate environment tasks, as a dict of form { task_name: alternate_queue }
"""
# The tasks below will be routed to the default lms queue.
return {
'completion_aggregator.tasks.update_aggregators': 'lms',
'openedx.core.djangoapps.content.block_structure.tasks.update_course_in_cache': 'lms',
'openedx.core.djangoapps.content.block_structure.tasks.update_course_in_cache_v2': 'lms',
}
@property
def explicit_queues(self):
"""
Defines specific queues for tasks to run in (typically outside of the cms environment),
as a dict of form { task_name: queue_name }.
"""
return {
'lms.djangoapps.grades.tasks.compute_all_grades_for_course': settings.POLICY_CHANGE_GRADES_ROUTING_KEY,
}