I just moved all my web applications to a really small vm (128 megs of memory) running linux xubuntu, with no GUI. Most of my applications run fine (if a bit slow, but that's acceptable) except for one. That one is a very small lightweight cgi application. Wordpress (php) and another jsp application run fine, but when I run the cgi, most of the time I get service temporarily unavailable. But sometimes, it works fine.
The vm is not swapping, and it's otherwise responding quickly. cpu is 90%+ idle. load average is nothing... 13:26:31 up 9 min, 2 users, load average: 0.00, 0.33, 0.34
How can I find out what's making apache decide to kick back a 503? There's nothing in any log. It doesn't even show an attempt to hit the url.
I have no idea where else to look. Any suggestions would be appreciated.
Okay, I'm an idiot. Turns out the reason it wasn't even showing up in the apache log was because dns was pointing somewhere else that was forwarding to my vm, and THAT webserver was overloaded. Lesson learned, follow the dns.