Tuesday, 12 April 2005
Try This RSS Experiment
Way back when I put the first Atom drafts together, I included a placeholder for a section that I hoped would allow reconstruction of feed state. Presently, this often isn’t necessary, because you have to be away for a seriously long time (e.g, on vacation) before you actually miss anything. However, I’d put forth that this state of grace is going to be increasingly unlikely.
Why? While your average, computer-obsessed geek — the main audience for syndication so far — won’t notice missing items because they obsessively check their feeds, more casual users will notice it as syndication goes prime-time. Furthermore, as people syndicate more and more types of information, it’s more likely that some feeds will change quickly enough that there’ll be problems.
In other words, if you happen to look away for too long you miss information, essentially making the channel leaky. To that end, I put together a proposal and a demonstration feed (in fact this very blog’s feed, dear reader), in the hopes of convincing people that this is a real issue. Silence ensued, and the ATOMPUB WG declined my proposal.
I wasn’t happy with that, but what to do? Rather than tilt at windmills, I’d like to try an experiment.
Set up two RSS aggregators. Get them both up-to-date on your usual selection of RSS feeds, and mark everything read.
Then turn one off.
Leave it that way for a day; i.e., have one aggregator running for 24 hours, the other dormant.
Now, fire the dormant aggregator up, let it sync, and look at the difference between them. It represents the updates, news and blog entries you miss when you’re offline for a day.
Now try it with a three-day gap (if this seems like unrealistic test conditions to you, please get professional help quickly).
- You won’t lose many (or any) entries from slow-moving news and information sources, or from all but the most prolific blogs.
- You might lose some entries from faster, stream-of-conciousness blogs (e.g., Dave Winer), mailing list feeds ( Yahoo! Groups) and aggregated or republishing feeds ( Planetizen, GridSkipper, craigslist, Technorati, RSSJobs)
- You’re pretty much guaranteed to lose entries from high-volume sources (e.g., Slashdot)
- If you’re subscribed to a monitoring feed (like pair.com’s system status feed or BT-EFNET’s feed), it totally depends on what happens on that day.
I’ll be back soon with my results.