upstream BACKEND {
  server 127.0.0.1:9000; #HHVM 
  server unix:/var/run/php5-fpm.sock backup; #PHP-FPM in backup mode
}

server {
 listen 80;
 server_name YOUR_SERVER_IP;

 root /var/www/sampleapp/app/webroot/;
 index index.php index.html;

 access_log /var/log/nginx/access.log;
 error_log /var/log/nginx/error.log;

 location / {
    try_files $uri $uri/ /index.php?$args;
 }
 
location ~ \.(hh|php)$ {
   fastcgi_pass BACKEND;
   proxy_next_upstream error timeout invalid_header http_500 http_504;
   fastcgi_read_timeout 30;
   fastcgi_keep_conn on;
   fastcgi_index index.php;
   fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
   include fastcgi_params;
 }
}