ApacheToday: Part VI: Forking and Executing Subprocesses from mod_perlFeb 28, 2001, 01:10 (0 Talkback[s])
(Other stories by Stas Bekman)
"It's desirable to avoid forking under mod_perl. Since when you do, you are forking the entire Apache server, lock, stock and barrel. Not only is your Perl code and Perl interpreter being duplicated, but so is mod_ssl, mod_rewrite, mod_log, mod_proxy, mod_speling (it's not a typo!) or whatever modules you have used in your server, all the core routines, etc."
"... But when a long term process needs to be spawned, there is not much choice, but to use fork(). We cannot just run this long term process within Apache process, since it'll first keep the Apache process busy, instead of letting it do the job it was designed for. And second, if Apache will be stopped the long term process might be terminated as well, unless coded properly to detach from Apache processes group."
"In the following sections I'm going to discuss how to properly spawn new processes under mod_perl."