While there have been hints of it before, Microsoft's commitment to support RFC3229+feed in the Windows RSS Platform Engine seems to have been restated more strongly today in a post on the Microsoft Team RSS Blog. The post is quite an interesting read as it gives some good hints as to what the folk at Microsoft are implementing. Anyone interested in the technical aspects of the blogging and syndication space should read this post in full. On the subject of RFC3229+feed they say:
Delta Encoding In addition to standard conditional GETs the RSS Platform download engine supports Delta Encoding (for details, see Bob Wyman's post "Using RFC 3229 with Feeds") which allows the server to respond with only the feed items that are new or have been updated, thereby possibly reducing the response significantly.
I think there will be a great deal of support in the community for Microsoft's helping us all reduce the bandwidth cost of growing the syndication web. RFC3229+feed will save many, many terabytes of otherwise wasted bandwidth. Unsurprisingly, some folk have already begun to blog in support of Microsoft's latest announcement.
This reminds me that it really has come time to prepare a formal IETF Internet Draft describing RFC3229+feed. It is time that we had something a bit more formal than a post on my blog as the documentation for this method. If anyone has any issues that should be addressed in such an ID, please let me know.
bob wyman
> This reminds me that it really has come time to prepare a formal IETF
> Internet Draft describing RFC3229+feed. It is time that we had something a
> bit more formal than a post on my blog as the documentation for this
> method. If anyone has any issues that should be addressed in such an ID,
> please let me know.
One issue I think would be very important to consider is integration with the Atom Publishing Protocol - as long as you don't get bogged down in the Atom standardisation process!!
Of course, the benefits of this approach go beyond 'mere' saving of bandwidth. You publish an update of some stuff using APP, then subscribers get a delta saying exactly what you've changed and can react according to the content of that delta. This not only saves bandwidth, but helps programmers because they needn't work out the diff themselves. You describe this in the blog entry you refer to (http://bobwyman.pubsub.com/main/2004/09/using_rfc3229_w.html).
Tying in update formats (APP) with event formats (RFC3229+feed) and other publish-subscribe mechanisms is the start of a nice event-driven programming model - it's not just feed update and notification we're looking at, here, but any data that APP is being applied to (and the list of APP-driven applications is growing). Whether deltas are fetched by GET in a polling way, or pushed by POST, or sent by XMPP is irrelevant to the basic model of pub-subbed resource changes - specifically, pub-subbed XML deltas.
Looking further ahead - a World-Wide Web of updating XML resources (linking to each other instead of to HTML), and you've got a dynamic semantic web!
Posted by: Duncan Cragg | April 25, 2006 at 08:10