[Wikitech-l] All non-api traffic is now served by HHVM

Hi all, it's been quite a journey since we started working on HHVM, and last week (November 25th) HHVM was finally introduced to all users who didn't opt-in to the beta feature. Starting on monday, we started reinstalling all the 150 remaining servers that were running Zend's mod_php, upgrading them from Ubuntu precise to Ubuntu trusty in the process. It seemed like an enormous task that would require me weeks to complete, even with the improved automation we built lately. Thanks to the incredible work by Yuvi and Alex, who helped me basically around the clock, today around 16:00 UTC we removed the last of the mod_php servers from our application server pool: all the non-API traffic is now being served by HHVM. This new PHP runtime has already halved our backend latency and page save times, and it has also reduced significantly the load on our cluster (as I write this email, the average cpu load on the application servers is around 16%, while it was easily above 50% in the pre-HHVM era). The API traffic is still being partially served by mod_php, but that will not be for long! Cheers, Giuseppe -- Giuseppe Lavagetto Wikimedia Foundation - TechOps Team