Lỗi 502 Bad Gateway của Web server

#user  nobody;
worker_processes  20;

worker_rlimit_nofile 51200;

events {
	use epoll;
    worker_connections 51200;
}

http {
        include       mime.types;
        default_type  application/octet-stream;

        log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                      '$status $body_bytes_sent "$http_referer" '
                      '"$http_user_agent" "$http_x_forwarded_for"';

	client_header_timeout   10m;
	client_body_timeout     10m;
	send_timeout            10m;
	client_max_body_size     4m;
	client_body_buffer_size    256k;

	connection_pool_size            256;
	client_header_buffer_size       1k;
	large_client_header_buffers     4 2k;
	request_pool_size               4k;

	output_buffers  1 32k;
	postpone_output 1460;

	tcp_nopush     on;
	tcp_nodelay    on; 
    sendfile        on;
    keepalive_timeout  120;

    gzip  on;
	gzip_comp_level  3;
	gzip_min_length  1100;
	gzip_buffers  4 8k;
	gzip_proxied any;
	gzip_types  text/plain text/css application/x-javascript text/xml application/xml application/xml+rss text/javascript; 
	
	upstream my_domain_vn {
		server 127.0.0.1:8080;
	}

	server {
		listen 						443;
		server_name     			my.domain.vn;
		
		ssl							on;
		ssl_certificate 			/usr/crtkiu2012/server.crt;
		ssl_certificate_key 		/usr/crtkiu2012/server.key;
		ssl_protocols  				SSLv2 SSLv3 TLSv1;
		ssl_ciphers  				ALL:!ADH:!EXPORT56:RC4+RSA:+HIGH:+MEDIUM:+LOW:+SSLv2:+EXP;
		ssl_prefer_server_ciphers   on;
		        
        access_log	/var/log/nginx/my.domain.vn.log;
		error_log	/var/log/nginx/my.domain.vn.vn_error.log;
		
        location / {
                proxy_pass      http://my_domain_vn;
                proxy_wwwect  off;
                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_set_header        X-Forwarded-Proto https;
        }
	}

	server {
                listen          80;
                server_name     www.my.domain.vn;
        location / {
                rewrite         ^/(.*)$ https://my.domain.vn/$1 wwwect;
        }
        }
    server {
                listen          80;
                server_name     my.domain.vn;
        location / {
                rewrite         ^/(.*)$ https://my.domain.vn/$1 wwwect;
        }
        }
}
worker processes 2; .... upstream localhost { server 127.0.0.1:8080; } .... proxy_pass http://localhost; proxy_read_timeout 75; proxy_connect_timeout 75;
Users currently in here
1 Anonymous