nginx会根据预先设置的权重转发请求, 若给某一台服务器转发请求时,达到默认超时时间未响应,则再向另一台服务器转发请求. 默认超时时间1分钟. 修改默认超时时间为1s:

server { 
        listen       80; 
        #server_name  localhost; 
        server_name  www.wuwh.com; 
        location / {  
        #proxy_pass         http://www.wuwh.com ;; 
        proxy_pass         http://www.wu.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;  
        proxy_connect_timeout 1; 
        proxy_read_timeout 1; 
        proxy_send_timeout 1; 
}