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Re: HTTP/2 Push deployed on webtide.com

From: Mark Nottingham <mnot@mnot.net>
Date: Tue, 19 Aug 2014 10:45:11 +1000
Cc: Simone Bordet <sbordet@intalio.com>, HTTP Working Group <ietf-http-wg@w3.org>
Message-Id: <FE5429E2-0133-4BC2-8740-7EAB3B4B451C@mnot.net>
To: Greg Wilkins <gregw@intalio.com>
My .02 - that seems to sum it up pretty well.


On 19 Aug 2014, at 9:55 am, Greg Wilkins <gregw@intalio.com> wrote:

> Note that there is a thread on the Servlet EG list regarding an API for push:
> https://java.net/projects/servlet-spec/lists/jsr340-experts/archive/2014-08/message/1
> where I've been asked some questions to describe "the rationalization used by the httpbis wg"
> Since I can't speak for the WG, I thought I'd echo my thoughts here regarding the push mechanism to check that I'm not misrepresenting anything:
> 	 Push is a server-side coordinated mechanism in as much as the server must decide to push a resourced based only on information that it already has.   Specifically h2 provides no information on the contents or status of downstream caches.   
> 	 Servers are free to innovate push strategies, with some of the following having been suggested:
> 		 Use knowledge from the web application/framework to determine what are associated resources.
> 		 Use heuristics derived from referrer headers and timing to infer what are associated resources
> 		 Use sessions to track what resources a client has requested/received to avoid unnecessary pushes 
> 		 Use the presence of if-modified headers to infer the status of a client cache to avoid unnecessary pushes.
> 	 There are no functional problems other than increased latency of not pushing an associated resource
> 	 There are no functional problems other than wasted bandwidth of pushing an unnecessary resource:
> 		 Clients can reset a pushed stream if they determine it is unnecessary.   Thus is a server attempts to push a resource that is already cached by the client, a RST will prevent wasting too much bandwidth.
> Hopefully nothing controversial or misrepresented there?
> cheers
> On 18 August 2014 18:57, Simone Bordet <sbordet@intalio.com> wrote:
> Hi,
> the Jetty team has deployed h2-14 with HTTP/2 Push functionality on
> https://webtide.com, see
> https://webtide.com/http2-push-with-experimental-servlet-api/.
> We are very interested in comments about how to make HTTP/2 Push
> better, so please try it out and tell us (also see discussion bullets
> towards the end of blog post).
> Thanks !
> --
> Simone Bordet
> ----
> http://cometd.org
> http://webtide.com
> http://intalio.com
> Developer advice, training, services and support
> from the Jetty & CometD experts.
> Intalio, the modern way to build business applications.
> -- 
> Greg Wilkins <gregw@intalio.com> 
> http://eclipse.org/jetty HTTP, SPDY, Websocket server and client that scales
> http://www.webtide.com  advice and support for jetty and cometd.

Mark Nottingham   https://www.mnot.net/
Received on Tuesday, 19 August 2014 00:45:38 UTC

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