Nginx-nginx fpm配置问题

Question

[14-Mar-2014 11:00:39] NOTICE: ready to handle connections
[14-Mar-2014 13:31:01] WARNING: [pool www] server reached pm.max_children setting (5), consider raising it
[14-Mar-2014 20:02:17] WARNING: [pool www] server reached pm.max_children setting (5), consider raising it
[15-Mar-2014 15:20:12] WARNING: [pool www] child 29639 said into stderr: "NOTICE: Access to the script '/home/static/images/blank.gif' has been denied (see security.limit_extensions)"
[15-Mar-2014 15:54:14] WARNING: [pool www] child 4848 said into stderr: "NOTICE: Access to the script '/home/static/images/blank.gif' has been denied (see security.limit_extensions)"
[16-Mar-2014 04:21:47] WARNING: [pool www] server reached pm.max_children setting (5), consider raising it
[16-Mar-2014 05:59:09] WARNING: [pool www] server reached pm.max_children setting (5), consider raising it
[16-Mar-2014 09:45:31] WARNING: [pool www] server reached pm.max_children setting (5), consider raising it
[17-Mar-2014 02:27:38] WARNING: [pool www] server reached pm.max_children setting (5), consider raising it

这个是什么问题？ 怎么解决？

Answer 1

在php-fpm的配置文件里面可以看到php-fpm分为两种运行模式：静态static和动态dynamic。还有以下四个设置：

pm.start_servers
pm.max_children
pm.min_spare_servers
pm.max_spare_servers

动态模式下服务启动时会启动pm.start_servers 个子进程，当空闲进程少于pm.min_spare_servers的时候会动态启动额外的进程，但不会超过pm.max_children 的值；当空闲进程超过pm.max_spare_servers时会自动杀死进程，但会使得空闲进程不少于pm.min_spare_servers。
静态模式下服务启动时会一下子创建pm.max_children条子进程，而其他pm.设置会无效，这些子进程会一直占用系统资源。

那么，查看日志

WARNING: [pool www] server reached pm.max_children setting (5), consider raising it

显示nginx的活动中子进程已经到了设置最大值。
你的最大子进程为5个，如果是测试用的服务器，可以了；但是对于一个上线服务器来说这个值太小了，建议可以设置为 服务器内存大小(mb)/30 个。其他的设置根据需求进行配置。

另外，如果服务器性能比较好，建议使用静态static模式；否则使用动态dynamic模式。