Django: Celery Worker not getting started (without any error)

Question

I am trying to configure djcelery in my Django Application backed by rabbitmq server on Ubuntu 14.04 machine hosted on Google Compute Engine.

On attempt to start celery in debug mode using: python manage.py celery worker -B -E --loglevel=debug, command is getting terminated with below output:

[2016-03-24 12:16:09,568: DEBUG/MainProcess] | Worker: Preparing bootsteps.
[2016-03-24 12:16:09,571: DEBUG/MainProcess] | Worker: Building graph...
[2016-03-24 12:16:09,572: DEBUG/MainProcess] | Worker: New boot order: {Timer, Hub, Queues (intra), Pool, Autoscaler, StateDB, Autoreloader, Beat, Consumer}
[2016-03-24 12:16:09,575: DEBUG/MainProcess] | Consumer: Preparing bootsteps.
[2016-03-24 12:16:09,576: DEBUG/MainProcess] | Consumer: Building graph...
[2016-03-24 12:16:09,577: DEBUG/MainProcess] | Consumer: New boot order: {Connection, Events, Mingle, Tasks, Control, Agent, Heart, Gossip, event loop}
<user>@<gce.host>:~/path/to/my/project$

What can possibly be the cause of this issue? The same setup is running on my local ubuntu machine and as far as I remember, I have followed all the steps on my cloud server.

---

Additional Info: Things I verified

1. RabbitMQ server is running fine. Output from log file:

=INFO REPORT==== 24-Mar-2016::17:02:14 === accepting AMQP connection <0.209.0> (127.0.0.1:42326 -> 127.0.0.1:5672)

=INFO REPORT==== 24-Mar-2016::17:02:14 === accepting AMQP connection <0.219.0> (127.0.0.1:42327 -> 127.0.0.1:5672)

=INFO REPORT==== 24-Mar-2016::17:02:17 === accepting AMQP connection <0.229.0> (127.0.0.1:42328 -> 127.0.0.1:5672)

2. Port 5672 is open on my machine. I have also opened port: tcp:5555, tcp:4369, tcp:15672, tcp:5671 as is mentioned here (to be on the safer side).

Celery's Configuration in my project:

Installed celery and django-celery package. Created rabbitMQ user and set its permissions with commands:

sudo rabbitmqctl add_user <user> <password>
sudo rabbitmqctl set_permissions -p / <user> ".*" ".*" ".*"

In settings.py file, I have added:

import djcelery
djcelery.setup_loader()

MIDDLEWARE_CLASSES = [ 'django.middleware.transaction.TransactionMiddleware',
                       ..]

INSTALLED_APPS = ['djcelery',
                  ..]

Content of celery.py is as:

from __future__ import absolute_import

import os

from datetime import timedelta
from celery import Celery
from celery.schedules import crontab

from django.conf import settings


# set the default Django settings module for the 'celery' program.
os.environ.setdefault('DJANGO_SETTINGS_MODULE', '<my_project>.settings')

app = Celery('<my_project>')

# Using a string here means the worker will not have to
# pickle the object when using Windows.
app.config_from_object('<my_project>.settings')
# app.autodiscover_tasks(lambda: settings.INSTALLED_APPS)

app.conf.update(
    CELERY_ACCEPT_CONTENT = ['json'],
    CELERY_TASK_SERIALIZER = 'json',
    CELERY_RESULT_SERIALIZER = 'json',
    BROKER_URL = 'amqp://<user>:<password>@localhost:5672//',
    # BROKER_URL = 'django://',
    CELERY_RESULT_BACKEND = "amqp",
    CELERY_IMPORTS = ("<module1>.tasks", "<module2>.tasks.tasks", "<module3>.tasks.tasks"),
    CELERY_ALWAYS_EAGER = False,
    # CELERY_RESULT_BACKEND='djcelery.backends.database:DatabaseBackend',
    # CELERY_TIMEZONE = 'Europe/London'
    CELERY_TIMEZONE = 'UTC',
    CELERYBEAT_SCHEDULE = {
        'debug-test': {
            'task': '<module1>.tasks.test_celery',
            'schedule': timedelta(seconds=5),
            # 'args': (1, 2)
        },
    }
)

Answer 1

Finally I was able to fix this. The version of celery and django-celery package on my system were different.

ubuntu@my-host:~/path/to/project$ pip freeze | grep celery
celery==3.1.21
django-celery==3.1.17

Changing celery version to 3.1.17 fixed it. To change the pip's package version, use:

ubuntu@my-host:~/path/to/project$ sudo pip install -I celery==3.1.17