Apache freezing, How to detect which virtual host is getting hit

apache-2.2loggingmemorytimeout

I have a production server that in the last 24 hours has been hard rebooted 4 times due to freezes. Ping is fine but all other services time-out (Apache, SSHd, etc). I have now diagnosed it to Apache running out of memory due to an exorbitant amount of child processes forking suddenly within seconds of starting Apache. Stopping Apache just after rebooting keeps the server stable again.

My two questions are:

  1. Is there a way to detect which of the vhosts is being suddenly hammered without looking into each vhost's access log one by one?

  2. Is there a way to quickly enable/disable vhosts without commenting (#) them all out in httpd.conf?

A few system details:

Fedora 10, x86_64, PHP 5, Apache 2.2

Best Answer

Try setting up a status page using mod_status. If you can get in after starting up your server you should see a page like this which shows each connection with its corresponding vhost, and URL.

If your site is so heavily flooded that you can't get in, try running netstat -nt | grep :80 or lsof -ni tcp:80 to see if one or two addresses are flooding your site and apply iptables accordingly.

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