求助一个 nginx+uwsgi+iptables 环境下遇到的问题。

cat /etc/nginx/conf.d/default.conf

server {
    listen       80;
    server_name  www.xxx.xxx;
    
    charset utf-8;

    location /test {
        include uwsgi_params;
        uwsgi_pass 127.0.0.1:3031;
    }
}

cat /etc/mblog/mblog.ini

[uwsgi]
socket = 127.0.0.1:3031
pidfile = /run/mblog.pid
wsgi-file = /usr/share/web_workspace/wsgi.py 
logto = /var/log/mblog.log
enable-threads = true
callable = app
processes = 2
threads = 2

iptables -nL

Chain INPUT (policy DROP)
target     prot opt source               destination         
ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0            tcp dpt:10086
ACCEPT     udp  --  0.0.0.0/0            0.0.0.0/0            udp dpt:53
ACCEPT     icmp --  0.0.0.0/0            0.0.0.0/0           
ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0            tcp dpt:80
ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0            tcp dpt:443

Chain FORWARD (policy ACCEPT)
target     prot opt source               destination         

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination

主要的配置和环境就是以上的信息。现在遇到了这个问题：访问 www.xxx.xxx 后，就一直在等待响应。。最终就是超时。看了下 nginx 的日志，就是 uwsgi 的超时导致的。。如果关掉 iptables 后，就可以正常访问了。。所以是哪一步出问题了？？

nginx 的 errorlog

2016/07/04 13:06:06 [error] 3689#3689: *1 upstream timed out (110: Connection timed out) while connecting to upstream, client: xxx.xxx.xxx.xxx, server: www.xxx.xxx, request: "GET / HTTP/1.1", upstream: "uwsgi://127.0.0.1:3031", host: "www.xxx.xxx"