The web server stopped serving all traffic this morning even though it was still running.  I’m assuming this is a bug in mod_qos which I installed yesterday to mitigate a type of denial of service attack as I’ve never seen this behavior from apache before.

     Consequently I’ve removed that module but still have some timeouts in place that should at least reduce the severity of this type of attack and will research the problem with mod_qos to see if either there is a fix or an alternate solution to this problem.