43Things, anything from 37Signals, or Odeo. But over the past year, there's no doubt that if there is a poster child for Rails, it is now Twitter. With such notorious bouts of downtime, a worse poster child Rails could not possibly hope for. But is Twitter even the largest application out there running on Rails? Does it even matter?Once upon a time, whenever anyone asked, "But are there any big applications built on Rails?" The answer was usually,
"Twitter is almost certainly the largest site running on Rails, so fans of the framework and its developers have been quick to deflect the criticism and point it back at the engineers at Twitter [to explain downtime]," wrote Nik Cubrilovic in a recent post on TechCrunch calling out Rails as a poor choice for large scale app development. The debates over what causes Twitter's frequent outages (we think it's a database issue) and whether Rails is good for large apps aside, Twitter might not actually be the biggest Rails-based app out there anymore.
Some back of the napkin math by noted rails developer Evan Weaver (who recently went to work for Twitter), finds that while Twitter might be huge in terms of monthly pageviews, the Facebook app Friends for Sale, may still be bigger. And Yellopages and Scribd are similarly massive.
Ignoring the oddities in Weaver's computation (like, for example, that even though he works at Twitter he only guesses how much traffic the API is fielding), which he admits result in "wildly inaccurate values," he makes one very good final point: It doesn't matter!
"It is important to keep in mind how useless this information is. It doesn't even make sense to say 'Rails site' or 'PHP site,'" says Weaver. "Livejournal uses Perl, Memcached, and MySQL, among other things. Does that make it a Perl site, a MySQL site, or a C site? I don't know what Scribd uses, but it's pretty likely that their document pre-renderer is Java or C, not Ruby. Friends for Sale uses Nginx, Rails, Memcached, MySQL, and Linux. Ruby is really just a little piece of the pie."