HHVM or HipHop Virtual Machine is an virtual machine that executes code written in PHP or Hacklang using a just-in-time (JIT) compilation approach to realize greater performance than would otherwise be achievable. 

In this post, I will be running through how to install and set up HHVM on an Ubuntu 14.04 Server set up using an Apache Virtual Hosts configuration. In the end, you will be able to run traditional and HHVM-based PHP-powered web applications side-by-side on the same system.

## Install HHVM
We don't need to all get fancy compiling anything, so we will simply install the prebuilt HHVM packages for Ubuntu 14.04 (64-bit). Run the following...

```bash
wget -O - http://dl.hhvm.com/conf/hhvm.gpg.key | sudo apt-key add -
echo deb http://dl.hhvm.com/ubuntu trusty main | sudo tee /etc/apt/sources.list.d/hhvm.list
sudo apt-get update
sudo apt-get install hhvm
```
*Source: https://github.com/facebook/hhvm/wiki/Prebuilt-Packages-on-Ubuntu-14.04*

Next, we need a way to hook HHVM into our Apache web server. This is done using FastCGI, which we will need to install. Luckily, HHVM provides a shell script to set this up. Run the following...

```bash
sudo /usr/share/hhvm/install_fastcgi.sh
```

Also, to ensure HHVM fires up at boot, run this...

```bash
sudo update-rc.d hhvm defaults
```

## Configure HHVM and Apache Virtual Hosts
The install script will ask you to restart both HHVM and Apache. Don't just yet, otherwise your site visitors will be seeing some 404 action coming their way. Instead, open hhvm_proxy_fcgi.conf and comment the single ProxyPassMatch line that's in there.

```bash
sudo nano /etc/apache2/mods-available/hhvm_proxy_fcgi.conf
```

```apacheconf
# ProxyPassMatch ^/(.+\.(hh|php)(/.*)?)$ fcgi://127.0.0.1:9000/var/www/$1
```

This stops all PHP/Hack scripts from being routed through FastCGI, this will allow you to choose which web applications you'd like to send through HHVM. If you're only running a single web application in your web server root, you don't need to do this, but I feel it's a smart move regardless. 

Right now HHVM is running but has no way for scripts to be handed off to it. We need to add the ProxyPassMatch configuration to the Virtual Host Configuration for the web applications we'd like HHVM to power. Add this to each Virtual Host instance in each configuration file (both secure and non-secure traffic covered in the example below.). 

```bash
sudo nano /etc/apache2/sites-available/hhvm.example.com.conf
```

```apacheconf
# HHVM Example - hhvm.example.com

<VirtualHost *:80>

	ServerName hhvm.example.com
    
	DirectoryIndex index.php
	DocumentRoot /var/www/sites/hhvm.example

	ProxyPassMatch ^/(.+\.(hh|php)(/.*)?)$ fcgi://127.0.0.1:9000/var/www/sites/hhvm.example/$1

</VirtualHost>
<VirtualHost *:443>

	ServerName hhvm.example.com
    
	DirectoryIndex index.php
	DocumentRoot /var/www/sites/hhvm.example
	
	SSLEngine On
	SSLCertificateFile 	 /etc/ssl/certs/hhvm.crt
	SSLCertificateKeyFile 	 /etc/ssl/private/hhvm.key
	SSLCACertificateFile  /etc/ssl/certs/hhvm.ca.crt

	ProxyPassMatch ^/(.+\.(hh|php)(/.*)?)$ fcgi://127.0.0.1:9000/var/www/sites/hhvm.example/$1

</VirtualHost>
```

#### *Pro-Tip*
You can also designate another port to explicitly use HHVM if you'd like to quickly A/B test the performance gains. To do this, simply open the port in /etc/apache2/ports.conf

```apacheconf
Listen 8080
```

Then in your Virtual Host configuration, create another instance with the new port specified and add the ProxyPassMatch configuration to the one you'd like to run HHVM on. 

```apacheconf
<VirtualHost *:80>

    ... 

</VirtualHost>
<VirtualHost *:8080>

    ... 

    ProxyPassMatch ^/(.+\.(hh|php)(/.*)?)$ fcgi://127.0.0.1:9000/var/www/$1

</VirtualHost>
```

## Restart Apache and HHVM
Now, we are ready to kick Apache and HHVM in the head. Restart both services...

```bash
sudo service apache2 restart
sudo service hhvm restart
```
The web application should load as you would normally expect, only a bit quicker. 

### *I'm getting 503'd!*
If you jumped over to your web application only to be greeted with a 503 error, this means you just need to fire up the daemon manually this first time or restart. Subsequent restarts will automatically fire this up.
```bash
hhvm --mode daemon -vServer.Type=fastcgi -vServer.Port=9000
```

## Testing
It's not immediately apparent whether your code is being passed through HHVM. There are a few ways to test this. 

### Client-Side
The easiest way to check if HHVM is doing it's thing is to inspect the response headers we get back from our web application. At the bottom of the header list, you will find **X-Powered-By** which should show **HHVM/3.2.0**.

To get to this, you can right click on the page, inspect any element, then click the "Network" tab in the developer tool panel. It will appear to be empty or nearly empty. Refresh the page and it will repopulate fully. Scroll to the top of the list and click the first item, it will be labeled with the domain name (hhvm.example.com in my case). 

### Server-Side
Drop the following into your application root and then access this script. If it returns **PHP**, it's not working. If it returns **HHVM**, you're golden!

```php
<?php 

if (defined('HHVM_VERSION')) {

	echo "HHVM";

} else {

	echo "PHP";

}
```

Install and configure HHVM on an Ubuntu 14.04 Server set up using an Apache Virtual Hosts configuration; run traditional and HHVM-based PHP-powered web applications side-by-side on the same system.

How To: Set Up and Configure HHVM on Ubuntu 14.04

We've all seen them, copyright statements in the footer with a date that's half a decade old. It makes you think, if this is so out of date, I wonder how they take care of the rest of their business. Even a copyright that's just a few years old is enough to make me think about things, and any reason for a customer to jump-ship, however small, is lost business. 

A quick way to make sure your copyright statement is current is to pull the information from the server's clock. Unless your server's date is off, which is highly unlikely, you can set up a simple bit of PHP to tap into that clock and make sure you're always displaying the current year. 

``` php
<?php echo date('Y'); ?>
```

**Example Usage:**
``` php
<div id="copyright-statement">
  Copyright <?php echo date('Y'); ?> ACME Widgets, All Rights Reserved.
</div>
```

Just pop that into any PHP-based page or footer template, add the standard HTML-based copyright copy and you're set, you can forget about it for another half-decade! 

Here are a few more examples for other languages

Javascript:
``` javascript
new Date().getFullYear()
```

Python:
``` python
import datetime
now = datetime.datetime.now()
print now.year
```

A quick way to make sure your copyright statement is current is to pull the information from the server's clock.

php

How To: Set Up and Configure HHVM on Ubuntu 14.04

How To: Always Keep Your Copyright Statement Up To Date