发现， 在配置文件中， 删除 admin 和 wordpress 的配置 都能访问成功，

重启 nginx， 服务器都不能解决此问题

问题重现

把 lb01 关机， lb02 上修改 为如下：

[root@lb02 /etc/nginx/conf.d]#cat lb_proxy.conf 
upstream blog {
        server 172.16.1.7:80;
        server 172.16.1.8:80;
}
server {
listen 80;
server_name zh.baimei.com;
    location / {
            proxy_pass http://blog;
            include proxy_params;
    }       

}

重启后 可以正常访问 admin.baimei.com

lb_proxy.conf 源文件：

[root@lb02 ~]#cat /etc/nginx/conf.d/lb_proxy.conf 
upstream blog {
        server 172.16.1.7:80;
        server 172.16.1.8:80;
}
server {
listen 80;
server_name wordpress.baimei.com;
    location / {
            proxy_pass http://blog;
            include proxy_params;
    }

}
server {
listen 80;
server_name admin.baimei.com;
    location / {
            proxy_pass http://blog;
            include proxy_params;
    }       

}
server {
listen 80;
server_name zh.baimei.com;
    location / {
            proxy_pass http://blog;
            include proxy_params;
    }       

}