Google recently released a tool to analyze a site and give performance suggestions: https://web.dev/
One of the biggest suggestions is to enable HTTP/2.
I found an old discussion about Moodle supporting it at https://moodle.org/mod/forum/discuss.php?d=283202, but couldn't find anything newer.
Is anyone running Moodle 3.4+ with HTTP/2? Any problems that we should be aware of before trying it out on our end?
If you are running it, do you see any tangible performance improvements?
Just ignore anything google has too say and you should be alright
In fact do the complete opposite to what google has too say
Just one specific example from the recent pass. We had (still only partly solved) major problem entering our credentials to a firewall from within the institution. For an unknown reason, this firewall sends an invalid certificate to clients in some networks. (Don't ask me why. I fear, even the network Tarzans don't know why.) Still could get the log-in form after I accepted the invalid cert. One fine day, Chrome (Goodle) said, No, Niente, Nada, sending us running for alternatives.
I haven't tried it, but it looks like there is some plans to tweak Moodle to take advantage of some of it's features: https://tracker.moodle.org/browse/MDL-52751
As far as I understand it, because it's fully backwards compatible, you could turn on HTTP/2 at the web server level (Apache or Nginx or whatever) and things should continue working as they normally do. The modern browsers that are capable of HTTP/2 will just continue running as before and if most of your users are using an HTTP/2 capable browser, you just start optimizing for it (in Moodle code or other) rather than the previous version. For example, Wordpress has plugins you can add that may make make the user experience a bit faster by pre-loading scripts/styles: https://wordpress.org/plugins/http2-server-push/
It won't give a free speedup though I think, the website has to be optimized for it's use before it helps.. but again, I haven't tested it.
Also, it's not just a Google thing. Google started the initiative but it's been standardised over 3 years ago now by the IETF. All recent browsers support it, other than Internet Explorer 11 on Windows 7. See https://caniuse.com/#feat=http2
For those of us that only serve up Moodle, I think there would be no benefit right now until wee see Moodle's code take advantage of it, but I am curious also if anyone has done tests to see if the multiplexing built into HTTP/2 speeds things up in Moodle without any code tweaks.
Looking at Moodle.org, actually it's all getting served over HTTP/2 and SPDY. Anyone from Moodle.org have any data on whether you got a speed up on using HTTP/2?