2011-11-26 08:31:59 +00:00
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RQ (_Redis Queue_) is a lightweight<sup>*</sup> Python library for queueing
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jobs and processing them in the background with workers. It is backed by Redis
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and it is extremely simple to use.
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2011-11-14 11:10:59 +00:00
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2011-11-26 08:31:59 +00:00
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<p style="font-size: 80%; text-align: right; font-style: italic">
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2011-11-26 12:46:22 +00:00
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<sup>*</sup> It is under 20 kB in size and just over 500 lines of code.</p>
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2011-11-15 23:37:59 +00:00
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2011-11-14 14:15:05 +00:00
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2011-11-26 08:31:59 +00:00
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## Getting started
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2011-11-14 14:15:05 +00:00
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2011-11-26 08:31:59 +00:00
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First, run a Redis server, of course:
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2011-11-14 14:15:05 +00:00
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2011-11-26 12:10:04 +00:00
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$ redis-server
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2011-11-14 14:15:05 +00:00
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2011-11-26 08:31:59 +00:00
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To put jobs on queues, you don't have to do anything special, just define
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your typically lengthy or blocking function:
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2011-11-15 21:45:51 +00:00
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2011-11-26 12:10:04 +00:00
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import urllib2
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2011-11-14 14:15:05 +00:00
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2011-11-26 12:10:04 +00:00
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def count_words_at_url(url):
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f = urllib2.urlopen(url)
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count = 0
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while True:
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line = f.readline()
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if not line:
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break
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count += len(line.split())
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return count
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2011-11-14 14:15:05 +00:00
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2011-11-26 08:31:59 +00:00
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Then, create a RQ queue:
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2011-11-14 14:15:05 +00:00
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2011-11-26 12:10:04 +00:00
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import rq import *
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use_redis()
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q = Queue()
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2011-11-14 14:15:05 +00:00
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2011-11-26 08:31:59 +00:00
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And enqueue the function call:
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2011-11-14 14:15:05 +00:00
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2011-11-26 12:10:04 +00:00
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from my_module import count_words_at_url
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result = q.enqueue(count_words_at_url, 'http://nvie.com')
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2011-11-15 22:00:55 +00:00
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2011-11-26 08:31:59 +00:00
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For a more complete example, refer to the [docs][d]. But this is the essence.
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2011-11-15 22:00:55 +00:00
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2011-11-26 08:31:59 +00:00
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[d]: {{site.baseurl}}docs/
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2011-11-15 22:00:55 +00:00
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2011-11-26 08:31:59 +00:00
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### The worker
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2011-11-15 22:00:55 +00:00
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2011-11-26 08:31:59 +00:00
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To start executing enqueued function calls in the background, start a worker
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from your project's directory:
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2011-11-15 22:00:55 +00:00
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2011-11-26 12:10:04 +00:00
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$ rqworker
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*** Listening for work on default
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Got count_words_at_url('http://nvie.com') from default
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Job result = 818
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*** Listening for work on default
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2011-11-15 22:00:55 +00:00
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2011-11-26 08:31:59 +00:00
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That's about it.
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2011-11-15 22:00:55 +00:00
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2011-11-26 08:31:59 +00:00
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## Installation
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2011-11-14 11:10:59 +00:00
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Simply use the following command to install the latest released version:
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pip install rq
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If you want the cutting edge version (that may well be broken), use this:
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2011-11-14 17:40:12 +00:00
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pip install -e git+git@github.com:nvie/rq.git@master#egg=rq
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2011-11-14 11:10:59 +00:00
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2011-11-15 23:53:56 +00:00
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2011-11-26 08:31:59 +00:00
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## Project history
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2011-11-15 23:53:56 +00:00
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This project has been inspired by the good parts of [Celery][1], [Resque][2]
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and [this snippet][3], and has been created as a lightweight alternative to the
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heaviness of Celery or other AMQP-based queueing implementations.
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2011-11-26 08:31:59 +00:00
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[m]: http://pypi.python.org/pypi/mailer
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[p]: http://docs.python.org/library/pickle.html
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2011-11-15 23:53:56 +00:00
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[1]: http://www.celeryproject.org/
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[2]: https://github.com/defunkt/resque
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[3]: http://flask.pocoo.org/snippets/73/
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