Related to Joe’s post about Microsoft’s RSS bandwidth issues, I’m seeing a lot of talk about the blogosphere about an RFC from January 2002: RFC 3229, “Delta encoding in HTTP.”
The idea behind this RFC is to just send the deltas — the changes — between a current document and the cached version of the document. So when an aggregator checked a feed, if there was a new post, the response would just send the new post (presumeably an XML fragment) and information on where to insert it in the old version.
Would this work? Sam Ruby is pretty pessimistic about it. On the other hand, there’s a good post over at PubSub that claims it’s very possible.
The bottom line is that something probably has to give with RSS polling. Like what happened with Microsoft, when tens of thousands of people start subscribing to a feed and polling the crap out of it, the system starts using bandwidth like a forest fire burns trees.
RSScache.com: Here's a free service to cache your RSS feed which we've talked about here and here. This site subscribes to your RSS feed, then translates that into a much narrower one for dissemination to end users. Users subscribe to the feed through this site, instead of through…
Since everyone but the janitor started blogging at Microsoft, they've been aggregating their blogs into one big honkin' feed that I call The Fire Hose, since reading it is like trying to drink from a fire hose. I find some interesting stories occasionally, but I probably missed 50 since I…
Sam Ruby has implemented it.
For a list of current server and client implementations of RFC3229 with the "feed" instance-manipulation method (including Sam Ruby's) see: http://bobwyman.pubsub.com/main/2004/09/implementations.html .
bob wyman
