I have recently presented “HTTP/2 and Java: Current Status” at a few conferences (slides below).
The HTTP/2 protocol has two big benefits over HTTP/1.1: Multiplexing and HTTP/2 Push.
The first feature, Multiplexing, gives an edge to modern web sites that perform ~100 requests per page to one or more domains.
With HTTP/1.1 these web sites had to open 6-8 connections to a domain, and then send only 6-8 requests at a time.
With a network roundtrip of 150ms, it takes ~15 roundtrips to perform ~100 requests, or 15 * 150ms = 2250ms, in the best conditions and without taking into account the download time.
With HTTP/2 Multiplexing, those ~100 requests can be sent all at once to the server, reducing the roundtrip time from 2250ms to ideally just 150ms.
HTTP/2 Push complements Multiplexing by saving the roundtrips needed to fetch all resources required to render a page.
The net result of these two features is a vastly improved web site performance which, following well known studies, can be directly related to more page views, and eventually to more revenue for your business.
The Jetty Project first implemented these features in SPDY in 2012, and improved them in HTTP/2.
We are now promoting this work to become part of the Servlet 4.0 specification.
The presentation I gave at conferences includes a demo that shows an example of HTTP/2 versus HTTP/1.1, available at GitHub.