My server: apache on Centos 5.2 32bit
My web server open port 80 and 443.
I use iptable to limit 30 SYN/s to anti attack DoS.
My problem: 2 last day, user access to port 80 very slow, access by http://myIP
also slow like http://mydomain
But I test access https(443), it's quick as normal
I see log HTTP, very litle log, not like attack.
System status: Number process http only <50, and CPU only < 25%; RAM <500MB/ 2GB avalable, HDD not access much.
So , I wonder why my webserver slow only on port 80
Really difficult to understand!