Celery + rabbitmq in result backend

Question

tasks.py:

from celery import Celery

app = Celery('tasks', broker='amqp://guest@localhost//')

@app.task
def add(x, y):
    return x + y

call.py:

from tasks import add

result = add.delay(1, 4)

result.ready()

celeryconfig.py: (in the same directory)

BROKER_URL = 'amqp://guest@localhost//'

CELERY_RESULT_BACKEND = 'amqp://guest@localhost//'

CELERY_TASK_SERIALIZER = 'json'

CELERY_RESULT_SERIALIZER = 'json'

CELERY_ACCEPT_CONTENT=['json']

CELERY_TIMEZONE = 'Europe/Oslo'

CELERY_ENABLE_UTC = True

In call.py I have en error:

AttributeError: 'DisabledBackend' object has no attribute '_get_task_meta_for'

I read the docs, I have result backend, why it does not work? How to fix that?

Thanks!

score 9 · Answer 1 · answered Oct 13 '14 at 07:46

You should not use Celery('tasks', broker='amqp://guest@localhost//') along with your celeryconfig.py file.

The way you should go (and the way of the documentation) is:

Create a package called mypackage (it is assumed that mypackage is not a sub package) with two files:

celery.py

from __future__ import absolute_import

from celery import Celery

app = Celery('mypackage',
             broker='amqp://guest@localhost//',
             backend='amqp://guest@localhost//',
             include=['mypackage.tasks'] #References your tasks. Donc forget to put the whole absolute path.
             )

app.conf.update(
        CELERY_TASK_SERIALIZER = 'json',
        CELERY_RESULT_SERIALIZER = 'json',
        CELERY_ACCEPT_CONTENT=['json'],
        CELERY_TIMEZONE = 'Europe/Oslo',
        CELERY_ENABLE_UTC = True
                )

tasks.py

from mypackage.celery import app
@app.task
def add(x, y):
    return x + y

Your call.py file is fine.

Start the Celery worker by using celery -A mypackage worker in command line, in the parent directory of mypackage.

Then you can start another Python interpreter, use call.py and voila!

I'm looking for how to use Rabbit as both broker and backend but I found in the docs that it shouldn't use amqp. [docs](http://celery.readthedocs.org/en/latest/configuration.html#std:setting-CELERY_RESULT_BACKEND) — chachan, Aug 18 '15 at 12:39
@AmichaiSchreiber you're right. I don't see it anymore. Sorry — chachan, Feb 09 '17 at 22:35

score -4 · Answer 2 · answered Oct 13 '14 at 06:57

-4

I find a bug in my code. In tasks.py:

app = Celery('tasks', broker='amqp://guest@localhost//', backend='amqp')

Needs backend parameter.

answered Oct 13 '14 at 06:57

Leon

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If you do that you will have issues with your configuration file, as you have a backend and a broker set twice. Assume you want to use a remote RabbitMQ broker, then which one do you change? – Flavian Hautbois Oct 13 '14 at 07:48

Celery + rabbitmq in result backend

2 Answers2