Is HHVM or PHP5 Zend running? - php

Question

After some struggle, I finally installed Facebook HipHop Virtual Machine in Ubuntu. It is running under FastCGI (Apache 2.22). Below, the service status:
marcelo#marcelo-VirtualBox:~$ service apache2 status
Apache2 is running (pid 3330).
marcelo#marcelo-VirtualBox:~$ service hhvm status
* hhvm is running
marcelo#marcelo-VirtualBox:~$ sudo service hhvm restart
* Restarting HHVM FastCGI Daemon hhvm [ OK ]
marcelo#marcelo-VirtualBox:~$
The same machine has PHP5 module enabled and configured in Apache.
Question:
I want to make sure that I am really rendering PHP code using HHVM and NOT Zend Framework.
All my PHP scripts are running on the webserver. But, when I disable PHP5 module using sudo a2dismod php5 the web server starts to render Internal Server Error.
Does HHVM need PHP5 module enabled to run? Supposedly, since I am using FastCGI, my answer is no. On the other hand, I think that my pages are being rendered by Zend and not HHVM.
What am I missing here? How can I make sure that I am really running HHVM? (in my mind, a clear test is to disable PHP5 module, but, as I said, when I disable, php stops working in the web browser).
If .php is not running with PHP5 module disabled does it means that my HHVM is not properly configured?
P.S.: The script that I am testing is a default Hello World example: <?php echo 'Hello World.'; ?>.
And, It works when I run from command line:
marcelo#marcelo-VirtualBox:/var/www$ sudo hhvm hello_world.php
Hello World.
marcelo#marcelo-VirtualBox:/var/www$
EDIT
Apache error.log:
marcelo#marcelo-VirtualBox:/var/log/apache2$ cat error.log
[Wed May 07 14:02:10 2014] [notice] FastCGI: process manager initialized (pid 2627)
[Wed May 07 14:02:10 2014] [notice] Apache/2.2.22 (Ubuntu) mod_fastcgi/mod_fastcgi-SNAP-0910052141 configured -- resuming normal operations
[Wed May 07 14:04:52 2014] [error] [client 127.0.0.1] (2)No such file or directory: FastCGI: failed to connect to server "/var/www/fastcgi/hhvm.fastcgi": connect() failed
[Wed May 07 14:04:52 2014] [error] [client 127.0.0.1] FastCGI: incomplete headers (0 bytes) received from server "/var/www/fastcgi/hhvm.fastcgi"
[Wed May 07 14:04:53 2014] [error] [client 127.0.0.1] File does not exist: /var/www/favicon.ico
marcelo#marcelo-VirtualBox:/var/log/apache2$
(Apparently, I should have 'hhvm.fastcgi' file. I only have the directory. Is anything wrong here?)
/var/www directory:
marcelo#marcelo-VirtualBox:~$ ls -l /var/www
total 20
drwxrwxrwx 2 root root 4096 May 6 23:45 fastcgi
-rw-r--r-- 1 root root 31 May 6 21:57 hello_world.php
-rw-r--r-- 1 root root 177 May 6 17:47 index.html
-rw-r--r-- 1 root root 21 May 6 17:50 info.php
-rw-r--r-- 1 root root 0 May 6 17:49 info.php~
drwxr-xr-x 13 997 1001 4096 May 6 18:13 mediawiki-1.22.6
marcelo#marcelo-VirtualBox:~$ ls -l /var/www/fastcgi/
total 0
marcelo#marcelo-VirtualBox:~$
- FastCGI configuration:
I added the lines below, as suggested here: https://github.com/facebook/hhvm/wiki/FastCGI, at the end of apache2.conf file. In other words, after all 'mods-enabled' were already loaded.
# fastcgi added by M. Sardelich
<IfModule mod_fastcgi.c>
Alias /hhvm.fastcgi /var/www/fastcgi/hhvm.fastcgi
FastCGIExternalServer /var/www/fastcgi/hhvm.fastcgi -socket /var/run/hhvm/socket -pass-header Authorization -idle-timeout 300
<Directory "/var/www/fastcgi">
<Files "hhvm.fastcgi">
Order deny,allow
</Files>
</Directory>
AddHandler hhvm-hack-extension .hh
AddHandler hhvm-php-extension .php
Action hhvm-hack-extension /hhvm.fastcgi virtual
Action hhvm-php-extension /hhvm.fastcgi virtual
</IfModule>

Answer 1

To make sure that you are in fact running HHVM, run the following command:
phpinfo();
It should produce HipHop as the output, instead of the normal php info.
To check for it programmatically, you can use the following (also mentioned here):
if (defined('HHVM_VERSION')) {
echo "ruuning HHVM";
}

Answer 2

As correctly noticed (thanks #Petah), my FastCGI config was wrong.
I changed it to the snippet below (from here: http://www.mediawiki.org/wiki/HHVM/Vagrant) and everything is working! (add it to your apache2.conf or httpd.conf file)
<IfModule mod_fastcgi.c>
Alias /hhvm.fastcgi /var/www/fastcgi/hhvm.fastcgi
FastCGIExternalServer /var/www/fastcgi/hhvm.fastcgi -host 127.0.0.1:9000 -pass-header Authorization -idle-timeout 300
<Directory "/var/www/fastcgi">
<Files "hhvm.fastcgi">
Order deny,allow
</Files>
</Directory>
AddHandler hhvm-hack-extension .hh
AddHandler hhvm-php-extension .php
Action hhvm-hack-extension /hhvm.fastcgi virtual
Action hhvm-php-extension /hhvm.fastcgi virtual
</IfModule>