CGI handling in Apache 2

• CGI handling is normally handled by mod_cgi
• mod_cgi will fork the apache process and exec the program
• This can result in a preformance penalty on some Unix systems where fork of a mthreaded process can be really slow
• mod_cgid is an external process which communicates with the apache process over a Unix socket
• mod_cgid is a single threaded process that forks without the cost
• Apache will restart mod_cgid if it dies (like reliable piped logs)