- From: Francois Daoust <fd@w3.org>
- Date: Tue, 24 Nov 2009 16:25:07 +0100
- To: Luca Passani <passani@eunet.no>
- CC: Julian Reschke <julian.reschke@gmx.de>, Tom Hume <tom.hume@futureplatforms.com>, public-bpwg-comments@w3.org
Luca Passani wrote: > Francois Daoust wrote: >> For clarification, the guidelines do not build on the assumption that >> GET is not safe. >> >> The mechanism described by Luca is actually recommended by the >> guidelines: send a GET with original headers, then send a request with >> modified headers if the first response is a "request unacceptable" >> response. > > Francois, this is not what I meant. What I meant is "content tasting". > Proxies should send a GET with original headers and if they get a > response (which they probably will), they should smell the response and > figure out whether that content may be good enough for mobile (and err > on the side of assuming it is). If the content is likely to be OK for a > mobile device, no transcoding should take place at all. Yes. That is precisely what I had understood. > This is explicitly ruled out by 4.1.5.1: > > http://www.w3.org/TR/ct-guidelines/#sec-content-tasting > > > "The theoretical idempotency of GET requests is not always respected by > servers. In order, as far as possible, to avoid misoperation of such > content, proxies *should* avoid issuing duplicate requests and > specifically *should not* issue duplicate requests for comparison > purposes." Yes. This is where the problem is and I personally agree that the document should be fixed (either by removing use of normative terms or by removing the paragraph). The intent was merely to alert transcoding proxies about practice vs. theory, and not to rule out content tasting that the guidelines explicitly encourage. [...] Thanks, Francois.
Received on Tuesday, 24 November 2009 15:25:37 UTC