I made a thread yesterday about my apache woes, but I think it went a little off course, and I now have a more understandable explanation of the problem.
It seems that Apache is lagging when trying to make the initial connection. Then once it connects, it loads quickly, and the subsequent keep-alive requests are as fast as ever, but once the Keep-Alive timeout has been reached and the connection killed, there is another lag to make a new connection.
Does anyone know what could be causing this problem? There are no performance issues when this is happening; server loads are low, memory usage is normal, traffic is light.
I am on a CentOS 3.5/CPanel server with 1gb of ram and dual 3ghz proc's, with APF and apache w/mod_sec/mod_dosevasive.
It can be caused by anything from firewall/ids config to buggy apache build.
Try to run Apache 'ab' utility from another machine, and see what stats it gives on Connect, Processing, and Waiting times, both with keep-alive turned on and off.
I'd also suggest creating a virtual host on some other port than 80 and checking it's speed. Also try building apache from sources with default settings (no mod_sec, mod_dosevasive etc) into different directory layout, and check it's speed.