Website hangs when sending some form or anything

Hello,

i moved my sites to new linux server of mine (apache, mysql, php).

From that time i experienced some bigger websites hanging for like 2-3 seconds before they start loadin. I mean when im browsing thru my website i click link, submit something and it waits saing in status field like "Waiting for mywebsite.com"

So i want to ask what apache, php etc values, what to check ons erver?

NOTE: my server is NOT overloaded (im checking "top -c" stats) so dont suggest me to upgrade etc.

I have impression that it is waited untill website elements are loaded and then webpage load very quickly afte mentioned 2-3 seconds delay..

thx

 

While your load may be OK, it could be that MySQL queries are taxing it briefly and causing a delay. Are the hardware specs of the new server better than those of the old server?

Another thing I see often when this happens is an improper resolver configuration (/etc/resolv.conf).

Try having ONLY this in your /etc/resolv.conf:

nameserver 4.2.2.2
nameserver 8.8.4.4

Remove any "search" lines. The default install of many OSs adds an improper "search" line to resolv.conf

If this is the problem, it is happening because your site(s) are loading elements from 3rd party locations.

Another idea to try is running strace. You will have to be quick but locate the apache process that is hanging and run:

strace -p PID

where PID is the process ID. It will usually give you some clue as to what is stalling. You can also try running the PHP script directly if it is a PHP script and viewing the system calls:

strace /home/path/to/your/php/file.php

If it is stalling because of the resolv.conf problem, you will see a lot of POLL_IN or POLL_OUT system calls.