When you running a highload website with PHP-FPM via FastCGI, the following tips may be useful to you : )
1. Compile PHP's modules as less as possible, the simple the best
(fast);
2. Increas PHP FastCGI child number to 100 and even more. Sometime,
200 is OK! ( On 4GB memory server);
3. Using SOCKET PHP FastCGI, and put into /dev/shm on Linux;
4. Increase Linux "max open files", using the following command (must
be root):
# echo 'ulimit -HSn 65536' >> /etc/profile
# echo 'ulimit -HSn 65536 >> /etc/rc.local
# source /etc/profile
5. Increase PHP-FPM open file description rlimit:
# vi /path/to/php-fpm.conf
Find "<value name="rlimit_files">1024</value>"
Change 1024 to 4096 or higher number.
Restart PHP-FPM.
6. Using PHP code accelerator, e.g eAccelerator, XCache. And set
"cache_dir" to /dev/shm on Linux.