I have a apache serve as a proxy to backend JBoss server, I use mod_proxy_loadbalancer. I also have some static files and resources I put it in an “upload" directory which configured as a directory in apache httpd.conf. I also enabled mod_mem_cache, as I have enought memory in that server. The server is a HP DL360 4 cores / 8G RAM / with RAID card and 15K SAS Disk.
My problem is many clients reports they open static files are very slow. When I track using FireBug, I can see sometime open an static files ( html / swf < 50kb) need around 5-7s. Both the server side bandwidth and the bandwidth in my office are enough. And when I monitor the server side, the average load in apache is about 20 requests /sec.
I have open the mod_status in the apache side, I can find many requests are in "R" status which means reading requests.
What does status reading means? Is this affect the speed of server response time? How can we reduce the "R" status requests in apache configuration.