Expiration of results - tasks not cleaned

[elavaud]

Hello,

• django = "^4.1.7"
• celery = "^5.2.7"
• redis = "^4.5.1"
• django-celery-results = "^2.4.0"
• django-celery-beat = "^2.4.0"

Sorry, a few posts already about this, but can not make it work.
I made a test project with the following settings (it is dumb, but I just want to try out celery)

settings.py:

CELERY_BROKER_URL = "redis://localhost:6379"
CELERY_RESULT_BACKEND = 'django-db'
CELERY_RESULT_EXTENDED = True
CELERY_RESULT_EXPIRES = 10

tasks.py:

@shared_task()
def list_users():
    return list(User.objects.values())

Then launched through a submission of form with

list_users.delay()

Three terminals running:

• ./manage.py runserver
• celery -A django_celery worker -l info
• celery -A django_celery beat -l INFO

First, I am a bit confused on the variable name to use. Some say to use CELERY_RESULT_EXPIRES some say CELERY_TASK_RESULT_EXPIRES. Anyway, none works.

Task results are well created, but never cleaned (well, at least not in the 10 seconds I set up).

Anything I missed?

[hetvi01]

JFYI:

1. Default task result will expire in one day and if we want to change that we need override the CELERY_TASK_RESULT_EXPIRES default time is in seconds. The task runs daily at 4am.
2. Default task clean up which delete the expired task from the task result table we'll run default at 4am(UTC) if beat is setup.

You can add this settings

 # your settings
 CELERY_BEAT_SCHEDULER='django_celery_beat.schedulers:DatabaseScheduler'
 CELERY_TASK_RESULT_EXPIRES=10

And for testing purpose that actually clean up job is running or not you can set below settings

celery_app.conf.beat_schedule = {
    'backend_cleanup': {
        'task': 'celery.backend_cleanup',
        'schedule': crontab(minute='15', hour='11'), # this time is in UTC
        'options': {'expires': 10},
    }
}

[saz]

FYI: Since Celery 4, CELERY_RESULT_EXPIRES should be used. CELERY_TASK_RESULT_EXPIRES is still valid, but might be removed in the future.

See also https://github.com/celery/celery/blob/f51c2bd8c175f5ea235da684aed870e5884fa941/docs/history/whatsnew-4.4.rst#configuration