I've just upgraded to 18.04 from 16.04 and am having a problem enabling HTTP/2 on my websites. First of all, my websites all use HTTPS.
I have done the following:
sudo a2enmod http2
added the following text to /etc/apache2/apache2.conf
Protocols h2 h2c http/1.1
and finished off with:
sudo systemctl restart apache2
As far as I am aware, that is all I need to do but none of my sites are working with HTTP/2 after doing the above operations. Can anyone lend a hand as to what I might be doing wrong, please?
Edit: I figured out what the problem was. I was using mod_php and mpm-prefork but in order to support HTTP/2 I needed to be using mpm_event and php7.2-fpm. I did this and got the sites working with HTTP/2 but now I have another problem. php7.2-fpm is timing out when I tried to start up upon reboot resulting in a 503 server error and I have no idea why it is timing out at all.