The other day I was continuing my long-term quest to sort through all the flotsam and jetsam of accumulated crap on my hard drive when I came across the following video (click through if you don't see the video below). Recorded in April 2009, it shows the first version of the TweetMeme Live functionality without any rate or minimum retweet restrictions. As you can see it moved pretty quickly.
Bear in mind that these are unique URLs, not simply repeats of URLs already seen. Between seeing a URL in a tweet and it appearing on this page the system has followed any redirects, grabbed and parsed the contents of the page and stuffed it into a database, and it does it all in near-realtime. Pretty impressive stuff if you ask me.
The live functionality on TweetMeme.com has now been removed, but it was great fun to develop and demonstrated the rate at which the site discovered and processed new URLs back in April 2009; you can bet the rate is far higher now given the explosion in the popularity of Twitter since then.
The implementation used long-polling requests connected to an nginx module which internally checked a queue for new items. While it didn't get a huge number of concurrent viewers during the time it was up on the site it scaled incredibly well for such a simple solution.
It's a shame that it's not available on the site anymore; it would be interesting to see how much the rate has increased in the past ten months.