Cancel an already executed Task

Harsh Jani

11y1.5kC#

Hi,

My question is How do you cancel an already executed task.

Lets say I have 10 tasks and I have put these tasks in a timer based "async" method. Since it is a timer based application, these tasks will be executed again and again. But, I don't want this to happen. If Task 1 is already finished then it should not be executed again.

Can anyone help me out in this regard with an example.

2 Replies

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Mukil Vendhan9y ago
If a task is revoked, the workers ignore the task and do not execute it. If you don't use persistent revokes your task can be executed after worker's restart.

http://docs.celeryproject.org/en/latest/userguide/workers.html#worker-persistent-revokes

revoke has an terminate option which is False by default. If you need to kill the executing task you need to set terminate to True.

>>> from celery.task.control import revoke >>> revoke(task_id, terminate=True)

http://docs.celeryproject.org/en/latest/userguide/workers.html#revoke-revoking-tasks

In Celery 3.1, the API of revoking tasks is changed.

According to the Celery FAQ, you should use result.revoke:

>>> result = add.apply_async(args=[2, 2], countdown=120) >>> result.revoke()

or if you only have the task id:

>>> from proj.celery import app >>> app.control.revoke(task_id)
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Akhil Garg11y ago
You can check TaskStatus.
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