Celery is a task queue with focus on real-time processing,while also supports task scheduling. Task queues are used as mechanisms to distribute work across multiple threads or machines. A task queues input is a unit of work called a task,dedicated worker processes and constantly moniter the queue for new work to perform. Celery communicates via messages using a broker to mediate between workers and clients.To initiate a task client puts a message on the queue, then the broker delivers that message to a worker.
Note: You can get more about celery http://celery.readthedocs.org/en/latest/django/first-steps-with-django.html
To run celery in virtual environment need to type the following command in your virtual environment
Running the worker with supervisor
In production you will want to run the worker in the background as a daemon and some times there may be a chance of stopping of celery worker automatically then it should be restarted automatically. To do thes tasks you need to use the tools provided like supervisord.
First, you need to install supervisor in your virtualenv and generate a configuration file.
$ pip install supervisor $ cd /path/to/your/project $ echo_supervisord_conf > supervisord.conf
Next, just add the following section in configuration file:
[program:celeryd] command=python manage.py celery worker -l info stdout_logfile=/path/to/your/logs/celeryd.log stderr_logfile=/path/to/your/logs/celeryd.log autostart=true autorestart=true startsecs=10 stopwaitsecs=600
It's a simplified version of the Celery supervisor configuration file, adapted to work with virtualenvs.
Just run supervisord in your project directory.
Running supervisor during startup or booting time
create a file /etc/init.d/supervisord and configure your actual supervisord.conf in which celery is configured in DAEMON_ARGS as follows
to run it
sudo chmod +x /etc/init.d/supervisord
and to automatically schedule it, do
sudo update-rc.d supervisord defaults
To Stop and Start the service
service supervisord stop service supervisord start
Running supervisor during startup or booting time using upstart(For Ubuntu users)
Create a new file /etc/init/supervisor.conf. Its content should look like this:
description "supervisor" start on runlevel  stop on runlevel [!2345] respawn chdir /path/to/supervisord exec supervisord
Note that we’re using the same supervisord configuration file we used before. No changes there…
We can now start and stop supervisord with the following commands
$ sudo stop supervisor $ sudo start supervisor