- From: イアンフェッティ <ifette@google.com>
- Date: Wed, 15 Aug 2012 10:56:31 -0700
- To: Patrick McManus <pmcmanus@mozilla.com>
- Cc: William Chan (陈智昌) <willchan@chromium.org>, Phillip Hallam-Baker <hallam@gmail.com>, "ietf-http-wg@w3.org Group" <ietf-http-wg@w3.org>
- Message-ID: <CAF4kx8cDta-sS-e-3WL7vsyXeJic=OX_pkEM+bp=9O0Dgugitg@mail.gmail.com>
In this scheme, perhaps you get a SRV record that tells you example.comsupports HTTP/2.0. Great. Does HTTP/2.0 exist on port 80? If so, although you know the end target supports HTTP/2, you have no idea about whether intermediaries support HTTP/2. If it's on a port other than 80/443 you can presume that if you can establish a connection it will be to a device/intermediary that understands HTTP/2, but experience shows we're going to successfully be able to establish connections only ~80% of the time. Perhaps we hope that firewalls adapt and open up whatever port gets used, but that's stacking the deck against us already... On Wed, Aug 15, 2012 at 10:48 AM, Patrick McManus <pmcmanus@mozilla.com>wrote: > sorry - too much shorthand. This is for http:// urls of course.. > https:// can just use npn on the A address. > > race A and SRV queries.. make best practice to bundle SRV answers as > additional information in responses to A queries. Best experience > returns an A bundled with SRV. But if you get an A without a bundled SRV > then go ahead and use it immediately for HTTP/1 and allow a > upgrade/alternate-protocol to do the bootstrapping that less ideal way. > > So its just an optimization. > > On Wed, 2012-08-15 at 10:19 -0700, William Chan (陈智昌) wrote: > > Can you elaborate how SRV would work here from a client perspective? > > Do you propose making the client block on the SRV lookup? Or are you > > proposing doing this out of band and switching to HTTP/2.0 if we > > discover support? > > > > > > http://code.google.com/p/chromium/issues/detail?id=22423#c9 has some > > of our thoughts on SRV in Chromium. > > > > > > > > On Wed, Aug 15, 2012 at 6:00 AM, Patrick McManus > > <pmcmanus@mozilla.com> wrote: > > On Tue, 2012-08-14 at 12:24 -0400, Phillip Hallam-Baker wrote: > > > > > If we take architecture seriously, the primary signaling > > mechanism for > > > HTTP/2.0 should be some form of statement in a DNS record to > > tell the > > > client 'I do HTTP 2.0'. We might also have some sort of > > upgrade > > > mechanism for use when the DNS records are blocked but that > > should be > > > a fallback. > > > > > > This is my current thinking as well though I'm not tied to > > it.. srv in > > the base case (with the possibility of dnssec) and something > > like > > upgrade/alternate-protocol over HTTP/1 as a slower fallback. > > > > > > > > > > > > > > > >
Received on Wednesday, 15 August 2012 17:56:59 UTC