>> I ran into an out of memory problem. The first mention of it in the >> kernel log is "mysqld invoked oom-killer". I haven't run into this >> before. I do have a swap partition but I don't activate it based on >> something I read previously that I later found out was wrong so I >> suppose I should activate it. Is fstab the way to do that? I have a >> commented line in there for swap. ... > If you're running any other servers that utilize MySQL like Apache or > something, check its access logs to see if you had an abnormal number > of connections. Bruteforce hacking or some kind of flooding/DOS attack > might cause it to use more memory than it ordinarily would.
I don't know why I didn't check the apache2 error log before, but I got the following entry 2 seconds before the server became unresponsive: [error] server reached MaxClients setting, consider raising the MaxClients setting I use the default 256 for MaxClients. This confirms the server was brought down by too many child processes consuming too much memory. Looking back at the access_log, it's clear this condition was caused by the single IP which requested one of my pages about 300 times over the course of 1 minute. This caused my entire server to lock up for hours until I rebooted it. I hesitate to reduce MaxClients from 256. I think my server should be able to handle it since it's the default. So I need to prevent my apache2 child processes from consuming so much memory? apache2 was restarted about an hour before the lockup so it had a pretty fresh start. I do use mod_perl which is a memory hog from what I understand. Do I just need more RAM? - Grant
