trying multiple server blocks on nginx

  upstream app_server {
    # for UNIX domain socket setups:
    server unix:/tmp/.sock fail_timeout=0;

    # for TCP setups, point these to your backend servers
    # server 127.0.0.1:8080 fail_timeout=0;
    # server 192.168.0.8:8080 fail_timeout=0;
    # server 192.168.0.9:8080 fail_timeout=0;
  }

  server {
    listen 80;
    server_name www.mydomain.it mydomain.it;
    location / {
      proxy_pass http://app_server/it;
    }
  }

  server {
    listen 80 default deferred;

    client_max_body_size 4G;
    server_name _;

    keepalive_timeout 5;

    # path for static files
    root /home/app_user/current/my_app/public/;

    # Prefer to serve static files directly from nginx to avoid unnecessary
    try_files $uri/index.html $uri.html $uri @app;

    location @app {
      proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

      proxy_set_header Host $http_host;

      proxy_redirect off;

      proxy_pass http://app_server;
    }

    # Rails error pages
    error_page 500 502 503 504 /500.html;
    location = /500.html {
      root /path/to/app/current/public;
    }
  }