Contrary to what many suggest, I decided to increase my keep-alive in apache from 1 to 5 seconds and to a maximum of 100 keep-alive requests per keep-alive connection from any one IP address. I also have apache in prefork MPM mode with 80 avaliable simultaneous connection slots (MinSpareServers = StartServers = MaxSpareServers = MaxClients = 80) As a result, my revenue from adsense increased slightly.
By long distance, I mean clients from one end of the world to the other.
I was looking into switching to worker MPM with php-fpm but since all requests require PHP to process (including the image processing and icon loading), I'm not sure if worker MPM creates a benefit for me. Additionally, my server has cpanel installed and their options won't allow me to run a faster server since I'm using apache prefork with ModRuid2.
The server is in quebec. When I access the page from a server in the same province, the page load time (time to first byte) takes under 150ms to load for first time request and about 30ms - 50ms TTFB after that. I made scans from random parts of the world far away from canada and the TTFB is relatively high, although it scores a B in webpagetest.org
Have I increased the keep-alive value high enough? and do I need to change other configuration settings in apache to make it easier for long distance clients to access the website?