Re: WordPress with Zend PHP

From: Alfredo Delgado
An early strength of PHP over other web scripting platforms was that
it runs as an Apache module instead of a separate CGI process ...

Could you elaborate on that? My understanding was that each PHP instance ran as a separate process - not as an HTTP server thread. Otherwise, why would the MaxClients directive apply to PHP? But I admit that I don't know whether that process is launched from mod_cgi, or mod_php. Does it matter?

By running PHP as a module, the extra steps of sending the request
off to an outside binary are removed and every Apache job basically
speaks PHP instead of just simply serving traffic.

Again, it would be helpful if you could elaborate.

Running as a separate process "may have" the advantage of separating an application server from a communication server, so that itinerant applications don't affect client-server communications - static content and so forth. That's not always the case. There have been cases where a bug in a CGI program has seized every thread in the HTTP server. I'm not sure what happens to PHP or the Apache server when they run buggy scripts.

Now why wouldn't everybody skip the proxy step?

Some folks use a proxy server anyway so that you have one server for static content, but another for dynamic content. The front-end server might be configured to run 1000 threads, while the back-end is configured to run 100.

But it's true that you're adding some latency due to inter-process communication.