RuntimeError: Never call result.get () in a Celery task

Question

I use celery to send a task to a remote server and try to return the result. Task status is constantly updated using the update_state method on the remote server.

I submit a task using

app.send_task('task_name')

Retrieving the results of a celery task is a blocking call, and I don't want my django application to wait for the result and timeout.

So, I tried to run another celery task to get the results.

@app.task(ignore_result=True)
def catpure_res(task_id):
    task_obj = AsyncResult(task_id)
    task_obj.get(on_message=on_msg)

But this leads to an error below.

Traceback (most recent call last):
  File "/usr/local/lib/python2.7/dist-packages/celery/app/trace.py", line 367, in trace_task
    R = retval = fun(*args, **kwargs)
  File "/usr/local/lib/python2.7/dist-packages/celery/app/trace.py", line 622, in __protected_call__
    return self.run(*args, **kwargs)
  File "/home/arpit/project/appname/tasks/results.py", line 42, in catpure_res
    task_obj.get(on_message=on_msg)
  File "/usr/local/lib/python2.7/dist-packages/celery/result.py", line 168, in get
    assert_will_not_block()
  File "/usr/local/lib/python2.7/dist-packages/celery/result.py", line 44, in assert_will_not_block
    raise RuntimeError(E_WOULDBLOCK)
RuntimeError: Never call result.get() within a task!
See http://docs.celeryq.org/en/latest/userguide/tasks.html#task-synchronous-subtasks

Is there any way around this error. Should I run the daemon process to get the results?

Answer 1

allow_join_result. . .

@app.task(ignore_result=True)
def catpure_res(task_id):
    task_obj = AsyncResult(task_id)
    with allow_join_result():
        task_obj.get(on_message=on_msg)

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Answer 2

, get - . get , :

result = catpure_res.AsyncResult(task_id, app=app)
    if result.ready():
        return result.get()

    return result.state

.

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