php-fpm服务维护实例以及参数说明

原文地址:https://blog.tanteng.me/2016/04/php-fpm-start-servers/

今天发了个链接，可能同时在线的人瞬间比较多，结果网站报503错误，回去打开php-fpm错误日志一看，php-fpm服务挂掉了，报如下错误：

[04-Apr-2016 15:38:04] NOTICE: systemd monitor interval set to 10000ms[05-Apr-2016 19:03:08] WARNING: [pool www] seems busy (you may need to increase pm.start_servers, or pm.min/max_spare_servers), spawning 8 children, there are 0 idle, and 29 total children[05-Apr-2016 19:03:09] WARNING: [pool www] seems busy (you may need to increase pm.start_servers, or pm.min/max_spare_servers), spawning 16 children, there are 0 idle, and 34 total children[05-Apr-2016 19:03:11] WARNING: [pool www] seems busy (you may need to increase pm.start_servers, or pm.min/max_spare_servers), spawning 32 children, there are 0 idle, and 39 total children[05-Apr-2016 19:03:12] WARNING: [pool www] seems busy (you may need to increase pm.start_servers, or pm.min/max_spare_servers), spawning 32 children, there are 0 idle, and 44 total children[05-Apr-2016 19:03:13] WARNING: [pool www] seems busy (you may need to increase pm.start_servers, or pm.min/max_spare_servers), spawning 32 children, there are 0 idle, and 49 total children[05-Apr-2016 19:03:14] WARNING: [pool www] server reached pm.max_children setting (50), consider raising it

错误提示建议增加pm.start_servers数量，打开我的php-fpm配置：

pm.max_children = 50; The number of child processes created on startup.; Note: Used only when pm is set to 'dynamic'; Default Value: min_spare_servers + (max_spare_servers - min_spare_servers) / 2pm.start_servers = 15; The desired minimum number of idle server processes.; Note: Used only when pm is set to 'dynamic'; Note: Mandatory when pm is set to 'dynamic'pm.min_spare_servers = 5; The desired maximum number of idle server processes.; Note: Used only when pm is set to 'dynamic'; Note: Mandatory when pm is set to 'dynamic'pm.max_spare_servers = 35

这里pm.start_servers之前我设置为5，注意配置文件也说明start_servers的值默认是max_spare_servers-min_spare_servers的一半。(ps:具体的值要根据服务器配置情况和压力测试得出)

网站服务器是阿里云1G带宽，1G内存，1核CPU配置，关键还在一台机子上装了数据库，redis各种服务。

几个php-fpm重要参数说明

pm.max_children = 24

static模式下创建的子进程数或dynamic模式下同一时刻允许最大的php-fpm子进程数量

pm.start_servers = 16

动态方式下的起始php-fpm进程数量

pm.min_spare_servers = 12

动态方式下服务器空闲时最小php-fpm进程数量

pm.max_spare_servers = 24

动态方式下服务器空闲时最大php-fpm进程数量

经验人士的总结：


一般php-fpm进程占用20~30m左右的内存就按30m算。如果单独跑php-fpm，动态方式起始值可设置物理内存Mem/30M，由于大家一般Nginx、MySQL都在一台机器上，于是预留一半给它们，即php-fpm进程数为$Mem/2/30。
 调整之后的几个值是：

Shellpm = dynamicpm.max_children = 50pm.start_servers = 15pm.min_spare_servers = 10pm.max_spare_servers = 4012345pm = dynamicpm.max_children = 50pm.start_servers = 15pm.min_spare_servers = 10pm.max_spare_servers = 40

重启php-fpm服务：service php70-php-fpm reload，继续使用top命令查看内存使用情况，发现十几个php-fpm启动。