Alexey Zakhlestin shares with us in this new blog post, how the fast-cgi PHP developers think they're using isn't really a true FastCGI.
Most PHP programmers believe, that PHP has support for FastCGI. They refer to fastcgi-sapi, which is bundled with php since long ago, and which was recently reimplemented for PHP 5.1.3/4. This SAPI really does exist and actually working quite good. But… it is not a real fast-cgi. It is just an imitation of mod_php which is linked against fastcgi api, instead of apache api. So, it's time for you to ask: if it exists and works, then what am I talking here about? Let's start from the basics...
He talks about a history of how things go to where they are, starting back with regular CGI scripts, moving up through using server-based APIs, and finally to FastcGI, a method for overcoming a lot of the limitations of its predecessors.
With that look back, he turns his attention around and looks to the current situation within PHP. He talks about the sudden appearance fastcgi made in PHP's SAPIs, but that the implementation wasn't true. He suggests that the reasoning behind this "fake" implementation was for the sake of speed. He also notes, however, it's his opinion that true FastCGI support in PHP will be a requirement for future large-scale applications.