Revoke Celery Tasks With Same Args/kwargs

Imagine having a long running task with a specific set of args and kwargs. Is there any chance to revoke all running and pending tasks with the same args/kwargs before starting a n

Solution 1:

If inspecting the workers is to slow, it might be better to check via a secondary data storage, for example a key-value store like redis. You add an "lock" for an function, so you know you already started it.

When queueing task:

• check if already exists in your store
  • yes: raise Exception
  • no: add relevant task info as item to your store.
• add task to celery task queue

A worker will execute it

• execute it
• remove from storage

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There is a redis based ready made implementation:

celery-once (permalink to current commit).

You have to specify it as a base of a task

from celery import Celery
from celery_once import QueueOnce

@celery.task(base=QueueOnce)defsum(a, b):
    ...

You can also specify which parameters to take into account and some more settings, read the readme there for more details.