- From: Jan Algermissen <jan.algermissen@nordsc.com>
- Date: Wed, 7 Sep 2011 22:18:26 +0200
- To: Julian Reschke <julian.reschke@gmx.de>
- Cc: HTTP Working Group <ietf-http-wg@w3.org>
On Sep 7, 2011, at 10:09 PM, Julian Reschke wrote: > On 2011-09-07 22:03, Jan Algermissen wrote: >> Hi Julian, >> >> >> On Sep 7, 2011, at 9:58 PM, Julian Reschke wrote: >> >>> On 2011-09-07 21:38, Jan Algermissen wrote: >>>> Dear WG, >>>> >>>> I have a question on the Expect header section 9.2 in HTTPbis 16[1] >>>> >>>> Is my understanding correct: >>>> >>>> 1. A proxy that finds an expectation extension in the Expect header that it does understand but cannot meet must respond 417 >>>> 2. A proxy that finds an expectation extension in the Expect header that it does not understand ignores the extension >>>> >>>> >>>> Jan >>>> >>>> [1] http://www.ietf.org/id/draft-ietf-httpbis-p2-semantics-16.txt >>> >>> "The Expect mechanism is hop-by-hop: that is, an HTTP/1.1 proxy MUST return a 417 (Expectation Failed) status code if it receives a request with an expectation that it cannot meet." >>> >>> I think that implies 417 for unknown extensions; how would the proxy "meet" the expectation when it doesn't know what it is? >> >> >> fair enough. >> >> But this means an extension can only be successfully defined and used when all intermediaries understand it - which is: never. >> >> Or am I getting this wrong? >> ... > > No, that's unfortunately correct. Maybe we need to mention it. Sorry to keep bugging - do you know the rationale behind this? Can't I have a mechanism that allows the client to ask specifically the origin server to only work on my request if it exhibits a certain behavior? And isn't that (also) the idea behind 'Expect'? Jan > > Best regards, Julian >
Received on Wednesday, 7 September 2011 20:18:55 UTC