upstream sitename_backend {
    server my_ip:8080;
}

server {
    listen   80;
    server_name www.sitename.ru sitename.ru;

    access_log /home/user/logs/sitename/nginx_access.log;
    error_log /home/user/logs/sitename/nginx_error.log;

    location / {
        proxy_pass  http://sitename_backend;
        include     /etc/nginx/proxy.conf;
        error_page 404 403 500 = @fallback;
    }

    location @fallback {
        proxy_pass http://sitename_backend;
    }

    location ~* \.(jpg|jpeg|gif|png|ico|css|bmp|swf|js)$ {
        root /home/user/www/sitename/;
    }
}