Facebook’s production servers have nearly doubled in throughput since the beginning of 2010, when the company first launched its home-grown application called HipHop for PHP.
Specifically, HipHop transforms PHP source code into highly optimized C++, and then compiles it with g++ to build binary files.
This reduces server usage by about half — or double throughput improvement, put in another way. Like Facebook Research Scientist Xin Qi says on the company’s engineering blog linked above:
At the time of the switch, HipHop reduced our average CPU usage by 50 percent the six months after its release saw an additional 1.8x performance improvement, and in the past six months the team in conjunction with the open source community has made an additional 1.7 times improvement…. Throughput is one of the most important metrics of server efficiency. It is defined as the average rate of web requests successfully served over a given period of time. Therefore, the work over the past several months has resulted in HipHop being able to serve roughly 70 percent more traffic on the exact same hardware infrastructure.
The graph below shows relative throughput gains on the Y axis and time on the X axis. Readers, what’s your opinion of this open-source technology?