rq/docs/patterns/index.md

title	layout
RQ: Using RQ on Heroku	patterns

Using RQ on Heroku

To setup RQ on Heroku, first add it to your requirements.txt file:

redis>=3
rq>=0.13

Create a file called run-worker.py with the following content (assuming you are using Redis To Go with Heroku):

{% highlight python %} import os import urlparse from redis import Redis from rq import Queue, Connection from rq.worker import HerokuWorker as Worker

listen = ['high', 'default', 'low']

redis_url = os.getenv('REDISTOGO_URL') if not redis_url: raise RuntimeError('Set up Redis To Go first.')

urlparse.uses_netloc.append('redis') url = urlparse.urlparse(redis_url) conn = Redis(host=url.hostname, port=url.port, db=0, password=url.password)

if name == 'main': with Connection(conn): worker = Worker(map(Queue, listen)) worker.work() {% endhighlight %}

Then, add the command to your Procfile:

worker: python -u run-worker.py

Now, all you have to do is spin up a worker:

{% highlight console %} $ heroku scale worker=1 {% endhighlight %}

If you are using Heroku Redis) you might need to change the Redis connection as follows:

{% highlight console %} conn = redis.Redis( host=host, password=password, port=port, ssl=True, ssl_cert_reqs=None ) {% endhighlight %}

and for using the cli:

{% highlight console %} rq info --config rq_conf {% endhighlight %}{% endhighlight %}

Where the rq_conf.py file looks like: {% highlight console %} REDIS_HOST = "host" REDIS_PORT = port REDIS_PASSWORD = "password" REDIS_SSL = True REDIS_SSL_CA_CERTS = None REDIS_DB = 0 REDIS_SSL_CERT_REQS = None {% endhighlight %}{% endhighlight %}

Putting RQ under foreman

Foreman is probably the process manager you use when you host your app on Heroku, or just because it's a pretty friendly tool to use in development.

When using RQ under foreman, you may experience that the workers are a bit quiet sometimes. This is because of Python buffering the output, so foreman cannot (yet) echo it. Here's a related Wiki page.

Just change the way you run your worker process, by adding the -u option (to force stdin, stdout and stderr to be totally unbuffered):

worker: python -u run-worker.py