Apache/Resource Limits
From Devpit
Apache supports resource limits on CGIs. See Apache's Manual for details on that. However, these only apply to processes that Apache starts, not Apache itself. When using mod_perl, it may be desirable to limit Apache itself. (Remember, mod_perl programs don't fork. mod_perl loads the Perl interpreter directly into Apache.) If you have mod_perl installed, an easy way to limit Apache is to add the following to startup.pl:
# Set limits Apache, and along with it, mod_perl programs. use BSD::Resource; my $prio = getpriority(PRIO_PROCESS, 0); setpriority(PRIO_PROCESS, 0, ((PRIO_MAX - $prio) / 4) + $prio); # lower priority setrlimit(RLIMIT_VMEM, 419430400, 419430400); # virtual memory, bytes setrlimit(RLIMIT_CPU, 30, 30); # CPU seconds