Test if a celery task is still being processed

Question

How can I test if a task (task_id) is still processed in celery? I have the following scenario:

Start a task in a Django view
Store the BaseAsyncResult in the session
Shutdown the celery daemon (hard) so the task is not processed anymore
Check if the task is 'dead'

Any ideas? Can a lookup all task being processed by celery and check if mine is still there?

Hey I am also looking for something similar to this, did you ever get around to resolving this? I am wondering whether to store the task_id in django's cache framework instead. I know I can use something like this http://dpaste.com/370419/ to get the status of the task. But am confused between using database, cache to store task_id. — Chantz, Jan 30 '11 at 23:18

score 3 · Accepted Answer · answered Jan 31 '11 at 03:32

define a field (PickledObjectField) in your model to store the celery task:

class YourModel(models.Model):
    .
    .
    celery_task = PickledObjectField()
    .
    .

    def task():
        self.celery_task = SubmitTask.apply_async(args = self.task_detail())
        self.save()

In case your task is not specific on any model you should create one specifically for the celery tasks.

or else I suggest using django-celery. It has a nice monitoring feature:
http://ask.github.com/celery/userguide/monitoring.html#django-admin-monitor, saves the tasks details in a django model in a nice graphical way.

Yes, I use django-celery and do lookups in the internal TaskMeta model to get the state. Thanks for the answer. — Reto Aebersold, Jan 31 '11 at 08:17

score 0 · Answer 2 · answered Jun 25 '14 at 23:39

I think there is a better way than to store a task object in the model. For example, in case you wanted to check if a group of task (parallel) have completed:

# in the script you launch the task
from celery import group

job = group(
    task1.s(param1, param2),
    task2.s(param3, param4)
)
result = job.apply_async()
result.save()

# save the result ID in your model
your_obj_model = YourModel.objects.get(id='1234')
your_obj_model.task_id = result.id
your_obj_model.save()

Then in your view

from celery.result import GroupResult
# ...
task_result = GroupResult.restore(your_obj_model.task_id)
task_finished = task_result.ready()
# will be True or False

Test if a celery task is still being processed

2 Answers2

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