网站出现500，查看SLOWLOG日志发现如下提示：
WARNING: [pool www] seems busy (you may need to increase pm.start_servers, or pm.min/max_spare_servers), spawning 32 children, there are 8 idle, and 58 total children
WARNING: [pool www] server reached pm.max_children setting (50), consider raising it
昨天晚上刚改的看来又不够用了！
查看PHP-FPM内存占用的几个有用小命令，记录如下：
1.查看每个FPM的内存占用：
ps -ylC php-fpm --sort:rss
当然，在后后面加 | wc -l可查看系统当前FPM总进程数，我的目前在45个左右。
PHP官方的建议设置值：
pm.max_children = Total RAM dedicated to the web server / Max child process size
2.查看FPM在你的机子上的平均内存占用：
[python] view plain copy
ps --no-headers -o "rss,cmd" -C php-fpm | awk '{ sum+=$1 } END { printf ("%d%s\n", sum/NR/1024,"M") }'
from:http://blog.csdn.net/solmyr_biti/article/details/50525021