what did you get? connection reset? 503 error?
Maybe PHP process need more memory to process uploaded file? Try increasing the memory limit for PHP from php.ini and in LSWS web console.
Yeah, there are so many settings can affect this. ;-)
add lsphp5 external app if not here yet. change script handler for "php" from lsphp4 to lsphp5.
Make sure you check the correct lsphp5 executable.
./lshphp5 -i
should show the configuration parameters.
Yes, I think SYN limit contribute to the problem at least.
You can try something like
ab -n 10 -c 1 -k http://hd-development.net/asfdafd
and
ab -n 10 -c 1 http://hd-development.net/asfdafd
form your pc, one use keepalive, one does not, the keepalive one will be finished in short time...
I think there is something wrong with your network configuration.
Maybe rate limited with iptables?
Please check packet drop, packet retransmission in your "netstat -s" output.
I got your email, and have checked it.
Your email server still bounce our reply email.
for fixing PHP 503 error, please check our trouble shooting guide in our wiki.
http://www.litespeedtech.com/support/wiki/doku.php?id=litespeed_wiki:php:lsapi#trouble_shooting
You have set the lsphp5...
Are you using PHP suexec with LiteSpeed, sometimes, PHP may have permission problem and may lead to higher load.
Some PHP code uses disk cache, for some reason, it causes high load problem when there is permission problem.
That's because PHP requests has all been handled by one or two lsphp processes, while with Apache mod_php, that load has been distributed among many Apache httpd processes. If add all the cpu usage of httpd processes up, it is higher than lshttpd + lsphp.