Nginx是一个高性能、轻量级的HTTP服务器，占用内存少，稳定性高，也可做为反向代理服务器。Nginx采用事件驱动，在Linux操作系统下，Nginx使用epoll事件模型，充分使用异步逻辑，削减了上下文调度开销，并发服务能力更强。

PHP-FPM是PHP的FastCGI 进程管理器，具有一些高级特性，将PHP进程管理与Web服务器分开，可以分开部署在不同机器上，监听不同的端口和使用不同的 php.ini 配置文件。

PHP-FPM特性之一：fastcgi_finish_request能够在请求完成和刷新数据后，继续在后台执行耗时的工作（录入视频转换、统计处理等），达到分离执行后台任务而又不阻塞PHP快速响应，可作为PHP性能优化点。

PHP-FPM另一特性：可以记录请求当中慢响应的日志，类似Mysql满日志，包括文件名，函数名，行号等，可用于分析PHP的性能问题。

在Apache + mod_php下，每一个请求，Apache便会启动一个进程并加载php解释器来处理。在Nginx + PHP-FPM下，Nginx将PHP请求和环境变量通过socket传递给FastCGI进程；将静态资源请求则缓存到本地并返回。FastCGI 进程管理器采用固定静态（或动态）的子进程来处理请求，占用内存少，具有更好的扩展能力。

在CentOs 6.4上安装Nginx和PHP-FPM：

yum search nginx
sudo yum install nginx
sudo chkconfig --levels 235 nginx on
sudo service nginx start

yum search fpm
sudo yum install php54-fpm

编辑php.ini

sudo vim /etc/php.ini

; cgi.fix_pathinfo provides *real* PATH_INFO/PATH_TRANSLATED support for CGI.  PHP's
; previous behaviour was to set PATH_TRANSLATED to SCRIPT_FILENAME, and to not grok
; what PATH_INFO is.  For more information on PATH_INFO, see the cgi specs.  Setting
; this to 1 will cause PHP CGI to fix its paths to conform to the spec.  A setting
; of zero causes PHP to behave as before.  Default is 1.  You should fix your scripts
; to use SCRIPT_FILENAME rather than PATH_TRANSLATED.
; http://www.php.net/manual/en/ini.core.php#ini.cgi.fix-pathinfo
cgi.fix_pathinfo=0

启动PHP-FPM

chkconfig --levels 235 php-fpm on
service php-fpm start

更改Nginx worker_processes配置

sudo vim /etc/nginx/nginx.conf

worker_processes  4;

更改Nginx 配置以便处理php请求

sudo vim /etc/nginx/conf.d/default.conf

server {
    listen       80 default_server;
    server_name  _;

    #charset koi8-r;

    #access_log  logs/host.access.log  main;

    # Load configuration files for the default server block.
    include /etc/nginx/default.d/*.conf;

    location / {
        root   /usr/share/nginx/html;
        index  index.html index.htm;
    }

    error_page  404              /404.html;
    location = /404.html {
        root   /usr/share/nginx/html;
    }

    # redirect server error pages to the static page /50x.html
    #
    error_page   500 502 503 504  /50x.html;
    location = /50x.html {
        root   /usr/share/nginx/html;
    }

    # proxy the PHP scripts to Apache listening on 127.0.0.1:80
    #
    #location ~ \.php$ {
    #    proxy_pass   http://127.0.0.1;
    #}

    # pass the PHP scripts to FastCGI server listening on 127.0.0.1:9000
    #
    location ~ \.php$ {
        root           /usr/share/nginx/html;
        #fastcgi_pass   127.0.0.1:9000;
        fastcgi_pass   unix:/tmp/php5-fpm.sock;
        fastcgi_index  index.php;
        fastcgi_param  SCRIPT_FILENAME  /scripts$fastcgi_script_name;
        include        fastcgi.conf;
    }

    # deny access to .htaccess files, if Apache's document root
    # concurs with nginx's one
    #
    #location ~ /\.ht {
    #    deny  all;
    #}
}

编辑PHP-FPM

sudo vim /etc/php-fpm.d/www.conf

; List of ipv4 addresses of FastCGI clients which are allowed to connect.
; Equivalent to the FCGI_WEB_SERVER_ADDRS environment variable in the original
; PHP FCGI (5.2.2+). Makes sense only with a tcp listening socket. Each address
; must be separated by a comma. If this value is left blank, connections will be
; accepted from any ip address.
; Default Value: any
;listen.allowed_clients = 127.0.0.1
listen = /tmp/php5-fpm.sock

; Set permissions for unix socket, if one is used. In Linux, read/write
; permissions must be set in order to allow connections from a web server. Many
; BSD-derived systems allow connections regardless of permissions.
; Default Values: user and group are set as the running user
;                 mode is set to 0660
listen.owner = nginx
listen.group = nginx
listen.mode = 0660

; Unix user/group of processes
; Note: The user is mandatory. If the group is not set, the default user's group
;	will be used.
; RPM: apache Choosed to be able to access some dir as httpd
user = nginx
; RPM: Keep a group allowed to write in log dir.
group = nginx

重启PHP-FPM

sudo service php-fpm restart

创建PHP页面

sudo vim /usr/share/nginx/html/info.php

<?php
phpinfo();

重启Nginx

sudo service nginx restart

测试PHP是否正确处理。

参考链接：
Nginx and PHP-FPM Configuration and Optimizing Tips and Tricks
nginx
FastCGI 进程管理器（FPM）
Apache + mod_php compared to Nginx + php-fpm
Which PHP mode? Apache vs CGI vs FastCGI
PHP: What are the advantages of FastCGI over mod_php?
What are the advantages of using PHP-FPM + Nginx over Apache and mod_php?
How To Install Nginx With PHP5 (And PHP-FPM) And MySQL Support On CentOS 6.5
How To Install Linux, nginx, MySQL, PHP (LEMP) stack on CentOS 6
Linux上配置Nginx+PHP5(FastCGI)
使用fastcgi_finish_request提高页面响应速度
善用php-fpm的慢执行日志slow log，分析php性能问题
swoole之代码热更新实现