Udo's Techblog

You know, in every field there is at least one subject that nobody is allowed to touch, like a sore spot if you will. A moldy can of lobster meat that has been in the fridge for years and now no one dares go near the damn thing. Everybody knows it's there, but they're in denial. It doesn't matter if the fridge has just been recognized as an independent civilization by the UN: people who point out the facts just get shot, or worse: they get ignored. (See how I'm carefully maneuvering around the expression "inconvenient truth"? Pure genius.)

Here's the deal: syndication doesn't really work. See, when a site publishes a feed, they usually publish the last ten items or so. That means when you subscribe to a feed, your RSS reader can also see only the last ten items.

Moreover, when the same reader accesses the same site some time later, it will get another ten items. Those may be (partially) the same as before or not. There is no guarantee, that those ten items represent everything that is new on the site. In fact, it often isn't. The reality is, items get skipped over, because readers can't access them in time.

Online readers mitigate the problem somewhat because their operators make sure to check the feeds for changes in regular intervals. Offline apps can't do that, though. So the two standard scenarios for any RSS update are either

- huge amounts of redundant data get transmitted

or

- data falls through the cracks and is never transmitted at all

And this is why syndication completely sucks as a protocol for notification.