Cast for two

Monday, July 20, 2009

Pubsubhubbub: a webhook based publish/subscribe

On Friday 9 July 2009, Google engineers Brad Fitzpatrick and Brett Slatkin showed a demo of a new realtime protocol called pubsubhubbub. This new technology could lead to a more reactive, pseudo realtime web. I my humble opinion, this might be much bigger news from Google then the announcement of Chrome OS. Of course, only the latter made a big splash in the mainstream news.

The issue of messaging is a topic addressed already many times in the course of computer science. Common wisdom is that the publish-subscribe pattern is a sound solution to this. The problem is that due to all kinds of practicalities it often regresses into a polling solution. Even with pubhubsubbub, the website that want to display realtime updates has to poll the hub to check if an update has happened. So there's still a nut to crack! In the example of a subscriber, a Javascript polls the hub to check for an update.

If anybody would know an implementation of the client that does not poll, please let me know.

In the demo at Techcrunch, updates made by blogger appeared almost realtime in google reader. Currenlty, not all blogger accounts support pubsubhubbub.

To be ready when your blogger account is updated, do not forget to add your feed to Feedburner and to activate Pingshot:
enable pingshot in feedburner
A pubsubhubbub plugin for wordpress exists and the Drupal community is probably already working on it. Check the overview of publisher code for clients on the pubsubhubbub project page.

Pushed on publish post on monday 20 Juli 2009, at 10:41. Updated at 11u17

1 comment:

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