利用Nginx做前置机负载均衡

基于树状的负载在应用层解决高并发问题，nginx做代理服务器进行负载均衡，场景如下：

1.本机模拟，模拟成3台

2.前置机为nginx，端口为80

3.应用服务器端口分别为8082和8083都以nginx进行模拟

4.nginx版本为：nginx-1.6.2

应用服务器1配置：

#user  nobody;
worker_processes  1;

events {
    worker_connections  1024;
}

http {
    include       mime.types;
    default_type  application/octet-stream;
    sendfile        on; 
    keepalive_timeout  65;
    server {
        listen       8083;
        server_name  localhost;
 
        location / {
            root   html;
            index  index.html index.htm;
        }
        error_page   500 502 503 504  /50x.html;
        location = /50x.html {
            root   html;
        }   
    }
}

应用服务器2配置：

#user  nobody;
worker_processes  1;

events {
    worker_connections  1024;
}

http {
    include       mime.types;
    default_type  application/octet-stream;
    sendfile        on; 
    keepalive_timeout  65;
    server {
        listen       8082;
        server_name  localhost;
 
        location / {
            root   html;
            index  index.html index.htm;
        }
        error_page   500 502 503 504  /50x.html;
        location = /50x.html {
            root   html;
        }   
    }
}

前置机配置：

#user  nobody;
worker_processes  1;

events {
    worker_connections  1024;
}

http {
    include       mime.types;
    default_type  application/octet-stream;
    sendfile        on;
    keepalive_timeout  65;

    upstream  linkrmb.com { 
         server  127.0.0.1:8083; 
         server  127.0.0.1:8082;
    } 
    server {
        listen       80;
        server_name  localhost;
 
        location / {
            proxy_pass         http://linkrmb.com; 
            proxy_set_header   Host             $host; 
            proxy_set_header   X-Real-IP        $remote_addr; 
            proxy_set_header   X-Forwarded-For  $proxy_add_x_forwarded_for; 
        }
    
        error_page   500 502 503 504  /50x.html;
        location = /50x.html {
            root   html;
        }
    }
}

前置机的代理配置主要点：

1.设置upstream

2.设置proxy_pass

默认的转发策略为轮询