On Wed, Jan 30, 2019 at 11:58:53AM +0000, Luke Seelenbinder wrote: > Hi Aleks, > > You're correct for http/1.1, but unfortunately, nothing I found after a > pretty long search indicated 1.8.x supports an h2 frontend with reusable > backend connections (h1.1 or h2).
I confirm, that was the main limitation of 1.8 and the reason for working on server-side connection pooling on 1.9. The reason is that in 1.8 the server side connections are attached to the streams, but while in 1.1 the stream is always the same for the connection, in H2 each request is one independent stream, thus once the response is delivered, the backend connection is lost. I tried hard to implement a very basic H2 keep-alive mode for 1.8 after the release but the architecture was really not suited to this. And seeing the difficulties and corner cases we've faced on this subject in 1.9, I'm happy not to have tried harder, as we would have broken lots of stuff. I hope to emit 1.9.4 in the middle of next week with many fixes making server-side keep-alive way more reliable (these are already in 2.0-dev). Regards, Willy
