Introduction

For setting up an instance of the queue service, see RunningQueueService.

When it's running standalone, you communicate with it via http requests. There are setup calls that you'd likely use once (or just put the data into the fixtures) to create a queue. Once you had a queue created, the time to insert something into the queue is the latency of making that http request and getting a response. Inserting into the queue (current release) is an HTTP Post, with the data being a string. If you want to toss around slightly more complex data structures, I'd recommend using JSON.

Something like the following:

import httplib2
client = httplib2.Http()
body_string = "message=%s" % (message_to_be_inserted_in_queue,)
(response,content) =
client.request(uri='http://dqshost:8000/q/queue_name_here/put',
method='POST', body=body_string)
if response['status'] != 200:
  print "Queue didn't accept the input"

The DQS architecture is based on Amazon's SQS, so removing a item from a queue is actually a two step process. You ask for the item at the top of the queue, and just asking for it makes it "invisible" to others for a certain timeout (our default is 5 minutes). If you don't come back and invoke an explicit "delete" on that item, it will become visible again for another process to pop it off the queue.

The component that drives that "every 5 minutes clear things up" isn't automatic, so in practice asking for something off the queue will make it invisible forever unless you implement the clearing of expirations as well. In practice, something like the following in a cron job running every 5 minutes works fine: curl -i http://dqshost:8000/q/queue_name_here/clearexpire/

While we've been working on the unstable branch and making this thing more REST like (as opposed to my bastard REST/RPC initial implementation), I put together a benchmark script to see how fast things were going - basically to make sure we didn't bork anything in the process of development. That script (http://django-queue-service.googlecode.com/svn/branches/unstable/benchmark.py) has a bunch of reasonably well encapsulated example calls to the DQS using urllib2 like the example above. Check it out for examples of getting something from the queue and deleting that item from the queue - the code should be pretty self-evident.

Details

Add your content here. Format your content with:

• Text in bold or italic
• Headings, paragraphs, and lists
• Automatic links to other wiki pages