Drupal and Hiphop php VM Faceboock has just released on GitHub their new Hiphop PHP VM, please follow this link:


https://github.com/Facebook/hiphop-php/wiki


Do you know if it is possible to enhance Drupal performance with HipHop PHP VM?

If yes, do you have a good howto, or the different steps to make it work, with a CDN?
At the time of writing Drupal does not work out-of-the-box with HipHop VM (1). Some people have managed to make it work with previous versions, but there isn't a simple easy option.

On php.webtutor.pl you can find a number of useful resources:


A benchmark of Drupal comparing standalone PHP, PHP with APC, and HipHop ;
The patch that was used to make Drupal run under Hiphop


These are for an older version of Drupal 7 (7.2) and an older version of Hiphop. However the patches are still useful as a place to start. Some of the issues addressed in the patches (eg. the infinite loop caused by drupal autoload) are still current - others may or may not be, I have not investigated further myself though the article by @tvlooy suggests the PDO issues have been fixed.

The article at http://nickveenhof.be/blog/getting-drupal-7-almost-running-hhvm (on which the tests by @tvlooy was based) provides an example configuration - even though the author failed to get Drupal to run under HHVM, it gives a helpful starting point in addition to the webtutor patches.

(1) As tested with Drupal 7.22 and the latest development version of HipHop (HEAD on the master branch) as of 01/08/2013

Edit: A post made on the 12/09/13 (after this answer was written) on the HHVM blog suggests that HHVM now passes 98% of Drupal core unit tests. There has been more HHVM releases since then - a comment on the 2.2.0 release that came out a month later suggests that Drupal 7 can be installed using HHVM, though file uploading, clean URLs and php-gd do not work. I do not want to change my original answer as I have not tested this myself, however the comment (together with the 2.2.0 changelog) suggests that some of the issues, such as the autoload loop, have been fixed.