Calculate by memory usage too. like if one php-fpm child process is taking 150 MB ram then 70 process will take 10,500 MB which will end up giving you 500 error and probably locking down the server. so choose wisely by using your brain. Good Luck.
Thanks. This my log
[22-Jan-2013 17:07:21] WARNING: [pool bachngocsach] server reached pm.max_children setting (5), consider raising it
[22-Jan-2013 17:08:22] WARNING: [pool bachngocsach] server reached pm.max_children setting (5), consider raising it
[22-Jan-2013 19:31:35] WARNING: [pool bachngocsach] server reached pm.max_children setting (5), consider raising it
[22-Jan-2013 19:46:54] WARNING: [pool bachngocsach] server reached pm.max_children setting (5), consider raising it
[22-Jan-2013 19:51:59] ERROR: unable to read what child say: Bad file descriptor (9)
[22-Jan-2013 20:46:03] WARNING: [pool bachngocsach] server reached pm.max_children setting (5), consider raising it
[22-Jan-2013 21:24:33] WARNING: [pool bachngocsach] server reached pm.max_children setting (5), consider raising it
[22-Jan-2013 21:47:16] WARNING: [pool bachngocsach] server reached pm.max_children setting (5), consider raising it
[22-Jan-2013 21:59:59] WARNING: [pool bachngocsach] server reached pm.max_children setting (5), consider raising it
[22-Jan-2013 22:07:46] WARNING: [pool bachngocsach] server reached pm.max_children setting (5), consider raising it
[22-Jan-2013 22:07:53] WARNING: [pool bachngocsach] server reached pm.max_children setting (5), consider raising it
[22-Jan-2013 22:29:44] ERROR: unable to read what child say: Bad file descriptor (9)
[22-Jan-2013 22:57:50] WARNING: [pool bachngocsach] server reached pm.max_children setting (5), consider raising it
[22-Jan-2013 23:25:17] WARNING: [pool bachngocsach] server reached pm.max_children setting (5), consider raising it
[23-Jan-2013 00:56:58] ERROR: unable to read what child say: Bad file descriptor (9)
[23-Jan-2013 00:56:58] ERROR: unable to read what child say: Bad file descriptor (9)
[23-Jan-2013 00:59:08] ERROR: unable to read what child say: Bad file descriptor (9)
[23-Jan-2013 00:59:08] ERROR: unable to read what child say: Bad file descriptor (9)
[23-Jan-2013 00:59:08] ERROR: unable to read what child say: Bad file descriptor (9)
[23-Jan-2013 00:59:08] ERROR: unable to read what child say: Bad file descriptor (9)
[23-Jan-2013 00:59:08] ERROR: unable to read what child say: Bad file descriptor (9)
[23-Jan-2013 00:59:08] ERROR: unable to read what child say: Bad file descriptor (9)
[23-Jan-2013 00:59:08] ERROR: unable to read what child say: Bad file descriptor (9)
[23-Jan-2013 00:59:08] ERROR: unable to read what child say: Bad file descriptor (9)
[23-Jan-2013 00:59:08] ERROR: unable to read what child say: Bad file descriptor (9)
[23-Jan-2013 00:59:08] ERROR: unable to read what child say: Bad file descriptor (9)
[23-Jan-2013 00:59:08] ERROR: unable to read what child say: Bad file descriptor (9)
[23-Jan-2013 00:59:08] ERROR: unable to read what child say: Bad file descriptor (9)
[23-Jan-2013 00:59:41] ERROR: unable to read what child say: Bad file descriptor (9)
[23-Jan-2013 00:59:41] ERROR: unable to read what child say: Bad file descriptor (9)
[23-Jan-2013 01:04:19] ERROR: unable to read what child say: Bad file descriptor (9)
[23-Jan-2013 01:04:19] ERROR: unable to read what child say: Bad file descriptor (9)
ERROR: unable to read what child say: Bad file descriptor (9)
hichic
