[bluejekyll]

What do you mean by stateful in this context?

Http/2 is multiplexed, unlike http/0.9-1.1, and while that has some overhead, it being a binary protocol probably makes up for it.

[merb]

The whole protocol has state, because that's the only way to multiplex multiple data streams over a single connection.

i.e.: https://http2.github.io/http2-spec/#StreamStates of course the "user layer" is stateless, but the whole connection handling is a state machine (which actually http/0.9-1.1 wasn't)