--- title: "RQ: Simple job queues for Python" layout: default --- RQ (_Redis Queue_) is a simple Python library for queueing jobs and processing them in the background with workers. It is backed by Redis and it is designed to have a low barrier to entry. It can be integrated in your web stack easily. RQ requires Redis >= 3.0.0. ## Getting started First, run a Redis server. You can use an existing one. To put jobs on queues, you don't have to do anything special, just define your typically lengthy or blocking function: {% highlight python %} import requests def count_words_at_url(url): resp = requests.get(url) return len(resp.text.split()) {% endhighlight %} Then, create a RQ queue: {% highlight python %} from redis import Redis from rq import Queue q = Queue(connection=Redis()) {% endhighlight %} And enqueue the function call: {% highlight python %} from my_module import count_words_at_url result = q.enqueue(count_words_at_url, 'http://nvie.com') {% endhighlight %} Scheduling jobs are similarly easy: {% highlight python %} # Schedule job to run at 9:15, October 10th job = queue.enqueue_at(datetime(2019, 10, 8, 9, 15), say_hello) # Schedule job to be run in 10 seconds job = queue.enqueue_in(timedelta(seconds=10), say_hello) {% endhighlight %} You can also ask RQ to retry failed jobs: {% highlight python %} from rq import Retry # Retry up to 3 times, failed job will be requeued immediately queue.enqueue(say_hello, retry=Retry(max=3)) # Retry up to 3 times, with configurable intervals between retries queue.enqueue(say_hello, retry=Retry(max=3, interval=[10, 30, 60])) {% endhighlight %} ### The worker To start executing enqueued function calls in the background, start a worker from your project's directory: {% highlight console %} $ rq worker --with-scheduler *** Listening for work on default Got count_words_at_url('http://nvie.com') from default Job result = 818 *** Listening for work on default {% endhighlight %} That's about it. ## Installation Simply use the following command to install the latest released version: pip install rq If you want the cutting edge version (that may well be broken), use this: pip install -e git+git@github.com:nvie/rq.git@master#egg=rq ## Project history This project has been inspired by the good parts of [Celery][1], [Resque][2] and [this snippet][3], and has been created as a lightweight alternative to existing queueing frameworks, with a low barrier to entry. [m]: http://pypi.python.org/pypi/mailer [p]: http://docs.python.org/library/pickle.html [1]: http://www.celeryproject.org/ [2]: https://github.com/defunkt/resque [3]: https://github.com/fengsp/flask-snippets/blob/1f65833a4291c5b833b195a09c365aa815baea4e/utilities/rq.py