Skip to main content
Donate to the Python Software Foundation or Purchase a PyCharm License to Benefit the PSF! Donate Now

Distributed Task Queue for Django

Project description

celery - Distributed Task Queue for Django.

Ask Solem (
:Version: 0.1.15


``celery`` is a distributed task queue framework for Django.
More information will follow.

Be sure to also consult the `API Reference Documentation`_

.. _`API Reference Docmentation`:


You can install ``celery`` either via the Python Package Index (PyPI)
or from source.

To install using ``pip``,::

$ pip install celery

To install using ``easy_install``,::

$ easy_install celery

If you have downloaded a source tarball you can install it
by doing the following,::

$ python build
# python install # as root


Have to write a cool tutorial, but here is some simple usage info.

*Note* You need to have a AMQP message broker running, like `RabbitMQ`_,
and you need to have the amqp server setup in your settings file, as described
in the `carrot distribution README`_.

*Note* If you're running ``SQLite`` as the database backend, ``celeryd`` will
only be able to process one message at a time, this because ``SQLite`` doesn't
allow concurrent writes.

.. _`RabbitMQ`:
.. _`carrot distribution README`:

Defining tasks

>>> from celery.task import tasks
>>> from celery.log import setup_logger
>>> def do_something(some_arg, **kwargs):
... logger = setup_logger(**kwargs)
..."Did something: %s" % some_arg)
>>> task.register(do_something, "do_something")

Tell the celery daemon to run a task

>>> from celery.task import delay_task
>>> delay_task("do_something", some_arg="foo bar baz")

Running the celery daemon


$ cd mydjangoproject
$ env DJANGO_SETTINGS_MODULE=settings celeryd
[2009-04-23 17:44:05,115: INFO/Process-1] Did something: foo bar baz
[2009-04-23 17:44:05,118: INFO/MainProcess] Waiting for queue.

Autodiscovery of tasks

``celery`` has an autodiscovery feature like the Django Admin, that
automatically loads any ```` module in the applications listed
in ``settings.INSTALLED_APPS``.

A good place to add this command could be in your ````,

from celery.task import tasks

Then you can add new tasks in your applications ```` module,

from celery.task import tasks
from celery.log import setup_logger
from clickcounter.models import ClickCount

def increment_click(for_url, **kwargs):
logger = setup_logger(**kwargs)
clicks_for_url, cr = ClickCount.objects.get_or_create(url=for_url)
clicks_for_url.clicks = clicks_for_url.clicks + 1"Incremented click count for %s (not at %d)" % (
for_url, clicks_for_url.clicks)
tasks.register(increment_click, "increment_click")

Periodic Tasks

Periodic tasks are tasks that are run every ``n`` seconds. They don't
support extra arguments. Here's an example of a periodic task:

>>> from celery.task import tasks, PeriodicTask
>>> from datetime import timedelta
>>> class MyPeriodicTask(PeriodicTask):
... name = ""
... run_every = timedelta(seconds=30)
... def run(self, **kwargs):
... logger = self.get_logger(**kwargs)
..."Running periodic task!")
>>> tasks.register(MyPeriodicTask)

For periodic tasks to work you need to add ``celery`` to ``INSTALLED_APPS``,
and issue a ``syncdb``.


This software is licensed under the ``New BSD License``. See the ``LICENSE``
file in the top distribution directory for the full license text.

.. # vim: syntax=rst expandtab tabstop=4 shiftwidth=4 shiftround

Change history

0.1.15 [2009-05-20 04:13 P.M CET]

* The celery daemon was leaking AMQP connections, this should be fixed, if you have any problems with too many files open (like ``emfile`` errors in ``rabbit.log``, please contact us!

0.1.14 [2009-05-19 01:08 P.M CET]

* Fixed a syntax error in the ``TaskSet`` class. (No such variable ``TimeOutError``).

0.1.13 [2009-05-19 12:36 P.M CET]

* Forgot to add ``yadayada`` to install requirements.

* Now deletes all expired task results, not just those marked as done.

* Able to load the Tokyo Tyrant backend class without django
configuration, can specify tyrant settings directly in the class

* Improved API documentation

* Now using the Sphinx documentation system, you can build
the html documentation by doing ::

$ cd docs
$ make html

and the result will be in ``docs/.build/html``.

0.1.12 [2009-05-18 04:38 P.M CET]

* delay_task() etc. now returns ``celery.task.AsyncResult`` object, which lets you check the result and any failure that might have happened. It kind of works like the ``multiprocessing.AsyncResult`` class returned by ``multiprocessing.Pool.map_async``.

* Added dmap() and dmap_async(). This works like the * ``multiprocessing.Pool`` versions except they are tasks distributed to the celery server. Example:

>>> from celery.task import dmap
>>> import operator
>>> dmap(operator.add, [[2, 2], [4, 4], [8, 8]])
>>> [4, 8, 16]

>>> from celery.task import dmap_async
>>> import operator
>>> result = dmap_async(operator.add, [[2, 2], [4, 4], [8, 8]])
>>> result.ready()
>>> time.sleep(1)
>>> result.ready()
>>> result.result
[4, 8, 16]

* Refactored the task metadata cache and database backends, and added a new backend for Tokyo Tyrant. You can set the backend in your django settings file. e.g

CELERY_BACKEND = "database"; # Uses the database

CELERY_BACKEND = "cache"; # Uses the django cache framework

CELERY_BACKEND = "tyrant"; # Uses Tokyo Tyrant
TT_HOST = "localhost"; # Hostname for the Tokyo Tyrant server.
TT_PORT = 6657; # Port of the Tokyo Tyrant server.

0.1.11 [2009-05-12 02:08 P.M CET]

* The logging system was leaking file descriptors, resulting in servers stopping with the EMFILES (too many open files) error. (fixed)

0.1.10 [2009-05-11 12:46 P.M CET]

* Tasks now supports both positional arguments and keyword arguments.

* Requires carrot 0.3.8.

* The daemon now tries to reconnect if the connection is lost.

0.1.8 [2009-05-07 12:27 P.M CET]

* Better test coverage
* More documentation
* celeryd doesn't emit ``Queue is empty`` message if ``settings.CELERYD_EMPTY_MSG_EMIT_EVERY`` is 0.

0.1.7 [2009-04-30 1:50 P.M CET]

* Added some unittests

* Can now use the database for task metadata (like if the task has been executed or not). Set ``settings.CELERY_TASK_META``

* Can now run ``python test`` to run the unittests from within the ``testproj`` project.

* Can set the AMQP exchange/routing key/queue using ``settings.CELERY_AMQP_EXCHANGE``, ``settings.CELERY_AMQP_ROUTING_KEY``, and ``settings.CELERY_AMQP_CONSUMER_QUEUE``.

0.1.6 [2009-04-28 2:13 P.M CET]

* Introducing ``TaskSet``. A set of subtasks is executed and you can find out how many, or if all them, are done (excellent for progress bars and such)

* Now catches all exceptions when running ``Task.__call__``, so the daemon doesn't die. This does't happen for pure functions yet, only ``Task`` classes.

* ``autodiscover()`` now works with zipped eggs.

* celeryd: Now adds curernt working directory to ``sys.path`` for convenience.

* The ``run_every`` attribute of ``PeriodicTask`` classes can now be a ``datetime.timedelta()`` object.

* celeryd: You can now set the ``DJANGO_PROJECT_DIR`` variable for ``celeryd`` and it will add that to ``sys.path`` for easy launching.

* Can now check if a task has been executed or not via HTTP.

You can do this by including the celery ```` into your project,

>>> url(r'^celery/$', include("celery.urls"))

then visiting the following url,::


this will return a JSON dictionary like e.g:

>>> {"task": {"id": $task_id, "executed": true}}

* ``delay_task`` now returns string id, not ``uuid.UUID`` instance.

* Now has ``PeriodicTasks``, to have ``cron`` like functionality.

* Project changed name from ``crunchy`` to ``celery``. The details of the name change request is in ``docs/name_change_request.txt``.

0.1.0 [2009-04-24 11:28 A.M CET]

* Initial release

Project details

Release history Release notifications

Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Filename, size & hash SHA256 hash help File type Python version Upload date
celery-0.1.15.tar.gz (276.8 kB) Copy SHA256 hash SHA256 Source None

Supported by

Elastic Elastic Search Pingdom Pingdom Monitoring Google Google BigQuery Sentry Sentry Error logging AWS AWS Cloud computing DataDog DataDog Monitoring Fastly Fastly CDN SignalFx SignalFx Supporter DigiCert DigiCert EV certificate StatusPage StatusPage Status page