PHP-FPM on highload tips

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.