Facebook's Open Source Virtual Machine HHVM Stabilized

Open source virtual machine project HHVM (HipHop Virtual Machine) has made a breakthrough. Facebook and WP Engine, which provides a WordPress-based content management platform, have enabled HHVM and PHP to run side by side, making HHVM more feasible for production. While the news will be of interest to developers, HHVM's maturity is something the industry at large should take into account.

Facebook, a company that continues to innovate up and down the stack from data center to application, originally created the open source project. HHVM is all about speeding up PHP execution. PHP is the foundation of Facebook and is heavily used across the Internet and within enterprises.

HHVM itself isn’t widely deployed or even widely known. It is extremely fast, but has not been considered production-ready because it sometimes causes system reboots. For the first time PHP and HHVM can run side by side on the same server, which increases speed, performance, and stability in production environments.

WP Engine's latest release, called Mercury, leverages the new capability.

“HHVM is extremely fast running WordPress,” said Tomas Puig, head of labs at WP Engine. “Getting it ready and stable is truly an accomplishment.”

WP Engine has over 23,000 customers, ranging from startups to Fortune 500. Modern websites with dynamic content built on HHVM can see an average response time increase 560 percent, the company said.

Mercury is in Alpha Labs production. Alpha Labs is a team at WP Engine dedicated to technical invention both inside and outside the company.

With Mercury, Puig said, WP Engine has achieved true data center redundancy using HHVM. The larger implications for the breakthrough of running HHVM and PHP on the same server means HHVM is ready and stable for wider adoption.

Early on in the HHVM project, the system would sometimes require rebooting which led to the belief that it wasn’t stable enough for production environments. In Mercury, PHP kicks in instantly to handle the load when HHVM requires resetting.

Puig said the Facebook team has been very responsive with the open source project. “We built the system in prototype and met up with them,” he said. “We felt we should be getting more performance, so they helped us tune the system for speed. They’ll close bugs. The Facebook team for open source is excellent.”

“The enhanced speed and performance by HHVM in production environments is an obvious boon for PHP developers and the WP Engine Labs team has done an impressive job in democratizing HHVM for the open-source community,” said Paul Tarjan, head of Open Source for HHVM at Facebook.

HHVM is designed to execute programs written in Hack and PHP and achieves superior performance by running PHP code exponentially faster than standard PHP 5.5.

The HHVM team’s goal is to be able to run all existing PHP code out in the wild. It can already run the top 20 Github PHP frameworks out of the box.