ecs 安装 Tengine version: Tengine/2.1.2 (nginx/1.6.2) 请求结果没有以“proxy_host”分类，proxy_host 为空；
请求： curl http://**.**.**.**:9009/reqstat
结果如下：
,12780,44757,142,142,142,0,0,0,0,0,0,0,0,142,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
配置如下：

http {
req_status_zone app "$proxy_host" 10M;

req_status_zone_add_indicator app $limit;
req_status app;

server {
    listen 9009;
    location /reqstat {
        req_status_show;

        allow 10.0.0.0/8;
        allow 127.0.0.0/8; 
        deny all; 
    }
    set $limit 0;
    if ($arg_limit = '1') {
        set $limit 1;
    }
}

}