hhvm_fallback

  location ~ \.(hh|php)$ {
    proxy_intercept_errors on;
    error_page 502 = @fallback;
    try_files $uri =404;
  
    fastcgi_split_path_info ^(.+\.php)(/.+)$;
    fastcgi_keep_conn on;
    include         /etc/nginx.custom.d/fastcgi_params;
    fastcgi_index   index.php;
    fastcgi_param   SCRIPT_FILENAME $document_root$fastcgi_script_name;
    fastcgi_param   SERVER_NAME $host;
    fastcgi_pass    127.0.0.1:9000;
  }
  location @fallback {
    try_files $uri =404;
    fastcgi_split_path_info ^(.+\.php)(/.+)$;
    include         /etc/nginx.custom.d/fastcgi_params;
    fastcgi_index   index.php;
    fastcgi_param   SCRIPT_FILENAME $document_root$fastcgi_script_name;
    fastcgi_param   SERVER_NAME $host;
    fastcgi_pass    unix:/var/run/php5-fpm.sock;
  }
  location / {
    try_files $uri $uri/ /index.php?q=$request_uri;
  }