- Background Processing
- Distributed
- Asynchronous/Synchronous
- Concurrency
- Periodic Tasks
- Retries

## Distributed Task Queue

Celery is a task queue/job queue based on distributed message passing. It is focused on real-time operation, but support scheduling as well.

The execution units, called tasks, are executed concurrently on one or more worker servers. Tasks can execute asynchronously (in the background) or synchronously (wait until ready).

Celery is already used in production to process millions of tasks a day.

Celery was originally created for use with Django, but is now usable from any Python project. It can also operate with other languages via webhooks.

### Example

This is a simple task adding two numbers:

    from celery.decorators import task

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

You can execute the task in the background, or wait for it to finish:

    >>> result = add.delay(8, 8)
    >>> result.wait() # wait for and return the result
    16

### Getting Started

1. Install celery by download or `pip install -U celery`
2. Set up RabbitMQ or one of the ghetto queue solutions.
3. Select one of the following guides:
   - First steps with Python
   - First steps with Django

### Community

There is a mailing-list available for general discussion.

For those craving real, human interaction, there is also an IRC channel (`#celery` on `irc.freenode.net`).

Finally, if you find a bug or would like to request a feature, please submit an issue.

## Celery 1.0.3 released!

#### By @asksol on 2010-05-15.

This release contains a drastic improvement in reliability and performance. Please read the full changelog before you upgrade. Download from PyPI, or simply install the upgrade using `pip install -U celery`.

## Celery 1.0.1 released!

#### By @asksol on 2010-03-20.

This is a bugfix release and has some important changes to the shutdown procedure. Also improved compatibility with Windows and Python 2.4. Read the full Changelog for more information. Download from PyPI, or simply install the upgrade using `pip install -U celery`.

## Celery 1.0 released!

#### By @asksol on 2010-02-10

Celery 1.0 has finally been released! It is available on PyPI for downloading. You can also install it via `pip install celery`. You can read the announcement here.

## 1.0 is in beta.

#### By @asksol on 2010-02-08

1.0 is scheduled to be released this week! Please help us test the latest release candiate to make this happen. To upgrade from an earlier version, please read the changelog.

## New website.

#### By @asksol on 2010-02-08

We finally got a home page. Big thanks to Jan Henrik Helmers

Copyright (c) 2009-2010, Ask Solem and contributors.
Page design by Jan Henrik Helmers