参考链接：https://blog.51cto.com/825536458/1784794
环境介绍
       192.168.127.131  nginx负载均衡 兼web服务器
       192.168.127.130  nginx负载均衡 兼web服务器

每台服务器上面有两个web站点分别是
 www.123.com
 www.hu.com 

说明：
准备用dns轮询解析来实现负载均衡，并且在两台server上面还同时启用了Nginx负载均衡，两台服务器是互为负载。前提是两台web服务端的网站内容一致。

配置过程：
在130负载均衡上面的操作：
在 上面编辑一个配置文件 vi /usr/local/nginx/conf/vhost/ld.conf 

 upstream 123{
     server 192.168.127.130:81;      
     server 192.168.127.131:81 ;    
     ip_hash;
   }     
    server {
     listen 80;
     server_name  www.123.com;
     location / {     
     proxy_pass http://123/;       
     proxy_set_header Host $host; 
      }
}
upstream hu {
   server 192.168.253.131:82;
   server 192.168.253.130:82;   
   ip_hash;
}
server {
    listen 80;
    server_name www.hu.com;
    location / {
        proxy_pass http://hu/;
        proxy_set_header Host   $host;
        
         }

更改 nginx负载服务器上面各个web主机的默认端口  

server
{
    listen 192.168.127.130:82;
    server_name www.hu.com;
    index index.html index.htm index.php;
    root /usr/local/nginx/html;
    location ~ \.php$ {
        include fastcgi_params;
        fastcgi_pass unix:/tmp/php-fcgi.sock;
        fastcgi_index index.php;
        fastcgi_param SCRIPT_FILENAME /usr/local/nginx/html$fastcgi_script_name;
    }
}

server
{
    listen 192.168.127.130:81 ;
    server_name www.123.com;
    index index.html index.htm index.php;
    root /data/www2;
    location ~ \.php$ {
        include fastcgi_params;
        fastcgi_pass unix:/tmp/php-fcgi.sock;
        fastcgi_index index.php;
        fastcgi_param SCRIPT_FILENAME /data/www2$fastcgi_script_name;
    }
}

131上面的配置：

server
{
    listen 192.168.127.131:81 ;
    server_name www.123.com;
    index index.html index.htm index.php;
    root /data/www2;
    location ~ \.php$ {
        include fastcgi_params;
        fastcgi_pass unix:/tmp/php-fcgi.sock;
        fastcgi_index index.php;
        fastcgi_param SCRIPT_FILENAME /data/www2$fastcgi_script_name;
    }
}

server
{
    listen 192.168.127.131:81 ;
    server_name www.123.com;
    index index.html index.htm index.php;
    root /data/www2;
    location ~ \.php$ {
        include fastcgi_params;
        fastcgi_pass unix:/tmp/php-fcgi.sock;
        fastcgi_index index.php;
        fastcgi_param SCRIPT_FILENAME /data/www2$fastcgi_script_name;
    }
}

同样的在 上面编辑一个配置文件 vi /usr/local/nginx/conf/vhost/ld.conf 
www.123.com

 upstream 123{
     server 192.168.127.130:81;      
     server 192.168.127.131:81 ;    
ip_hash;
}
server {
     listen 80;
     server_name  www.123.com;
     location / {       
     proxy_pass http://123/;       
     proxy_set_header Host $host;  
     }
}
upstream hu {
   server 192.168.253.131:82;
   server 192.168.253.130:82;   
   ip_hash;
}
server {
    listen 80;
    server_name www.hu.com;
    location / {
        proxy_pass http://hu/;
        proxy_set_header Host   $host;
  
    }

最后分别启动nginx服务并查看端口是否正常启动
测试：分别在两个网站的目录里添加1.txt测试文件，里面写上不同的内容然后用浏览器访问 www.hu.com/1.txt，刷新几次
同样的，www.123.com/1.txt也是这样