Application Development: Google Fashioning PubSubHubbub as RSS on Steroids

 
 
By Clint Boulton  |  Posted 2009-08-24
 
 
 

Google Fashioning PubSubHubbub as RSS on Steroids

by Clint Boulton

Google Fashioning PubSubHubbub as RSS on Steroids

PubSubHubbub

The PubSubHubbub protocol has its own colorful logo. Check out the ensuing flow chart for how it works.

PubSubHubbub

A Subscriber

A subscriber polls a publisher's feed. The feed contains a forward link to the Hub.

A Subscriber

The Subscriber

The subscriber posts a subscription request to the Hub. The request contains the URL where the Hub should post new updates.

The Subscriber

The Hub

The Hub posts to the endpoint URL to verify the request was authentic. The subscriber then responds with confirmation to the Hub.

The Hub

The Publisher

The publisher notifies the Hub about updates by posting feed URLs to the Hub. The Hub pulls the feed again to find new entries.

The Publisher

When the Publisher Does not Tell the Hub About Updates

If the publisher does not inform the Hub, the Hub will periodically poll the Publisher's feed for new updates.

When the Publisher Does not Tell the Hub About Updates

Receiving Feed Updates

When the Hub receives a new update to a feed, it posts the update to the Subscriber's endpoint URL.

Receiving Feed Updates

What if There Are Multiple Subscribers?

If feed X has multiple subscribers, the Hub sends updates to all of them.

What if There Are Multiple Subscribers?

The Distribution

The future is distributed: There will be big hubs, many small hubs and tons of publishers and subscribers. Publishers, subscribers and hubs may play multiple roles.

The Distribution

PubSubHubbub Requirements

This is what publishers, subscribers and hubs need for the protocol to work.

PubSubHubbub Requirements

Rocket Fuel