upstream  backServer{

    server 127.0.0.1:81;

    server 127.0.0.1:82;

}

    server {

        listen       80;

        server_name  wg.com;

       location / {

    ### 指定上游服务器负载均衡服务器

    proxy_pass http://backServer/;

            index  index.html index.htm;

        }

    }