Wikipedia Adopts HHVM
Cunningham named his software after a Hawaiian word for “quick.” That’s why the Wikimedia Foundation is happy to report that editing Wikipedia is now twice as quick. Over the last six months we deployed a new technology that speeds up MediaWiki, Wikipedia’s underlying PHP-based code. HipHop Virtual Machine, or HHVM, reduces the median page-saving time for editors from about 7.5 seconds to 2.5 seconds, and the mean page-saving time from about 6 to 3 seconds. Below, I’ll explain the technical background for HHVM on MediaWiki and some of the far-reaching benefits of this change that will go beyond the recent performance gains.
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Resolving fidelity issues required some effort, but it turned out well. After we had already been working on the conversion for several months, Facebook approached us offering to donate some developer time to help with this task.
A large investment in HHVM or Hack today seems to be worthwhile only if you’re paying much more for PHP CPU usage than engineering salaries, you have a lot of unused engineering capacity to migrate to and maintain the new setup (which takes more effort than official PHP because it’s so bleeding-edge), and your codebase is so large that it’s infeasible to start migrating away from PHP.
