http {
	// ....
}
 
stream {
 	log_format simple '$remote_addr [$time_local] $protocol $status';
    # 包含动态生成的中国 IP 列表
    include /usr/local/nginx/china_ips_dynamic.conf;
 
    deny all;
 
    upstream iot_data_service {
        server 127.0.0.1:8080;
    }
 
    server {
        listen 8081;
        proxy_pass iot_data_service;
 
        proxy_timeout 24h;       # 24小时超时
        proxy_responses 0;       # 保持连接直到客户端断开
 
        tcp_nodelay on;
 
        proxy_next_upstream on;
        access_log /home/.nginx/logs/tcp_access.log simple;
    }
}