I don't know if this is the right forum. This isn't a new PHP install, its more of just a config problem ( i assume ) that has recently shown itself. Anyway, I have a new problem. PHP can no longer fork out external programs 95% of the time.
This has been going on for the past week. You see, for the past week, I've been under a form of DoS attack on my server. Thousands of different users loading the same one page on one of my web sites, over and over. I'm averaging 200-300 page loads per second, with peaks upwards of 1200 per second. I was able to block these abusers, and now apache is sending them text only, super short 403 errors. Its working pretty good, percentage wise, my server's load is pretty low. The problem is, since this started apache can't run external programs. It least, usually it can't. Clearly these two events are related, but I don't see how. I checked and Mac OS X Server has a limit of 1000 process per user. Thats pretty high. Apache is configured to have only 450 simultaneous connection. Keepalive times out after only 2 seconds. Users 'www' should never even be able to get close to the user limit! Keep in mind that 99% of my traffic right now is abusers that are getting a short text '403' error and nothing else. No php, no cli programs, no mysql. Sever load is 20-30% usually, when I'm not in a spike. And my load averages often hover right around 1.00 or even drop below that. I can ssh into the machine and run anything I want. I have no idea what is causing these unable to fork errors.
This is what I get when using exec( ) to try to display 'uptime'
Warning: exec() [function.exec]: Unable to fork [uptime] in /Users/johnm/webfolder/webservices/uptime.php on line 1
This is what I get when I use backticks to run 'whois'
Warning: shell_exec() [function.shell-exec]: Unable to execute 'whois phpfreaks.com'
Again I know this problem is related to all this extra load my server is under, but I don't know how, and I don't know how to fix it. My server isn't under THAT much load, there must be a misconfigured setting somewhere? Something like that?
