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Re: WG Review: Recharter of Hypertext Transfer Protocol Bis (httpbis)

From: Willy Tarreau <w@1wt.eu>
Date: Sun, 26 Feb 2012 07:40:25 +0100
To: Patrik Fältström <patrik@frobbit.se>
Cc: John C Klensin <john-ietf@jck.com>, Patrik Fältström <paf@frobbit.se>, Andrew Sullivan <ajs@anvilwalrusden.com>, "mnot@mnot.net" <mnot@mnot.net>, IETF Discussion <ietf@ietf.org>, "iesg@ietf.org" <iesg@ietf.org>, "ietf-http-wg@w3.org" <ietf-http-wg@w3.org>
Message-ID: <20120226064025.GH8633@1wt.eu>
On Fri, Feb 24, 2012 at 05:57:31PM +0100, Patrik Fältström wrote:
> I am asking more generally why specifically this DNS issue is so stuck,
> because I think that is unfair. We upgrade other protocols...

Because in HTTP, anybody can be anywhere. You can have client-side proxies,
server-side gateways, load balancers, etc... everyone in this chain may or
may not resolve, it's only a matter of configuration and architecture choice.
There are plenty of places where clients won't access public resolvers at all
and rely on their proxies for this. So you can't make use of DNS to improve
these users' experience.

Also, DNS is SLLLLOOOOWWWWW. It's fast enough to send a mail. But for HTTP
it adds too much latency. Some people in the mobile world would like to be
able to configure an explicit proxy on their smartphones in order to avoid
a very expensive round trip before fetching an object : at 20 host names
on a web page, 300 ms round trip means 6 seconds are lost to resolve these
objects if they can't be totally parallelized.

DNS suggestion is something going back and forth regularly. I think that
people who try to push it hard only see the very simple case where users
have a direct low-latency internet connection. The reality is much much
different. This well reflected by the fact that in the end, after many
proposals, it has still not been adopted !

Received on Sunday, 26 February 2012 06:44:12 UTC

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