In this tutorial, you will learn how to upgrade and configure Apache for HTTP/2 on Ubuntu 16.04 (working for Ubuntu 18.04 and 20.04 as well, according to our friendly commenters). The steps are not complicated, but since you’ll be upgrading the main Apache package you should make a snapshot (or other backup) of your server in case things go pear-shaped.
The default version of Apache that is available in Ubuntu 16.04 doesn’t come with HTTP/2 support – at least, not yet. Luckily, to make the switch from HTTP/1.1 to HTTP/2, you can use an unsupported (by Ubuntu) but stable release of Apache to get it working.
Why HTTP/2? As a protocol, HTTP/2 has a clear and simple purpose: to make the Internet better for everyone. It does this by improving on the technical shortcomings of HTTP/1.1, and it also adds new features like multiplexed TCP streams and Server Push. If you would like to know how exactly HTTP/2 makes the Internet better, then read “http2 explained”, a definitive paper written by Daniel Steinberg of Mozilla.
- Step 1: Upgrade Apache from PPA
- Step 2: Tell Apache to use PHP FastCGI
- Step 3: Change MPM from “prefork” to “event”
- Step 4: Add a line to your Virtual Host file
- Step 5: Enable the mod_http2 Apache module
- Step 6: Test your Apache server for HTTP/2
- Useful resources
- A self-managed VPS or dedicated server with Ubuntu 16.04 running Apache 2.4.xx.
- A registered domain name with HTTPS (TLS/SSL). HTTP/2 only works alongside HTTPS because most browsers, including Firefox and Chrome, don’t support HTTP/2 in cleartext (non-TLS) mode.
Step 1: Upgrade Apache from PPA
Let’s assume you installed Apache from the standard stable Ubuntu repository using apt. When you check your version of
apache2 by typing:
… you’ll notice that Apache 2.4.18 is the current default version for Ubuntu 16.04. However, you need Apache 2.4.24 or later for compatibility with HTTP/2.
To get a newer version of Apache, you can use the PPA from Ondřej Surý which includes the latest stable release (Apache 2.4.27 at time of writing). Ondřej is a prominent PHP developer in the Debian community, so this PPA is considered safe.
To add the PPA, type:
sudo add-apt-repository ppa:ondrej/apache2
Or, you can add the PPA manually by inserting these lines into /etc/apt/sources.list:
deb http://ppa.launchpad.net/ondrej/apache2/ubuntu xenial main deb-src http://ppa.launchpad.net/ondrej/apache2/ubuntu xenial main
Once the PPA is added, update and upgrade Apache:
sudo apt update sudo apt upgrade
This will update and upgrade
apache2 to Apache 2.4.27+.
Step 2: Tell Apache to use PHP FastCGI
You want to make Apache use a compatible PHP implementation by changing
php-fpm (PHP FastCGI). If your website or app breaks on FastCGI, you can always revert back to
mod_php until further troubleshooting.
Install the PHP FastCGI module for PHP 7.0 (replace with “7.1” if desired):
sudo apt install php7.0-fpm
Enable the required modules,
sudo a2enmod proxy_fcgi setenvif
sudo a2enconf php7.0-fpm
sudo a2dismod php7.0
sudo service apache2 restart
Step 3: Change MPM from “prefork” to “event”
Since the default “prefork” MPM (Multi-Processing Module) is not fully compatible with HTTP/2, you’ll need to change Apache’s current MPM to “event” (or “worker”). This is shown by the error message in Apache versions later than 2.4.27 as –
AH10034: The mpm module (prefork.c) is not supported by mod_http2.
Keep in mind that your server requires more horsepower for HTTP/2 than for HTTP/1.1, due to multiplexing and other factors. That said, smaller servers with low traffic may not see much difference in performance.
First, disable the “prefork” MPM:
sudo a2dismod mpm_prefork
Enable the “event” MPM:
sudo a2enmod mpm_event
Restart Apache and PHP 7.0:
sudo service apache2 restart
sudo service php7.0-fpm restart
Step 4: Add a line to your Virtual Host file
Add the following line to your site’s current Virtual Host config file. This can go anywhere between the
<VirtualHost>...</VirtualHost> tags. If you want to serve HTTP/2 for all your sites, add this to your global /etc/apache2/apache2.conf file instead of per each individual site’s Virtual Host file.
Protocols h2 h2c http/1.1
h2 is TLS-encrypted HTTP/2,
h2c is cleartext HTTP/2, and
http/1.1 is ordinary HTTP/1.1.
http/1.1 at the end of the line provides a fallback to HTTP/1.1, while
h2c is not strictly necessary.
Step 5: Enable the mod_http2 Apache module
Now you can enable the
http2 module in Apache:
sudo a2enmod http2
sudo service apache2 restart
Step 6: Test your Apache server for HTTP/2
Method 1: “Inspect Element” in browser
Open the developer panel on your web browser by right-clicking anywhere on your website and selecting “Inspect Element” from the context menu.
Go to the Network tab, and then refresh your browser. You should see all the HTTP requests listed. Click on a request to view raw header information. In the header, you should see “HTTP/2.0” or “h2”. Here’s what you will see if it is working correctly:
Method 2: Run an online HTTP/2 Server Test
You can test whether HTTP/2 is working on your server by plugging your domain name into the HTTP/2 Server Test from KeyCDN.
More information on your server can be found by using the SSL Labs Server Test.
- Learn about what you can do with mod_http2 (Apache Docs): https://httpd.apache.org/docs/2.4/mod/mod_http2.html
- Read Apache’s HTTP/2 guide: https://httpd.apache.org/docs/2.4/howto/http2.html
- See this extensive HTTP/2 FAQ: https://http2.pro/doc/Apache
Tom Davis is a technical contributor at TechWombat. He enjoys writing on IT, open source, electronics, and other geeky arcana. Tom’s always happy to reply to comments and corrections, so be nice and send him your thoughts at email@example.com or in the comment section below.