- From: Matthias Schunter <mts@zurich.ibm.com>
- Date: Wed, 12 Oct 2011 00:41:28 +0200
- To: public-tracking@w3.org
Hi JC, thanks for this valuable input to our discussion of response headers. I believe that it is important to investigate the potential benefits: Why do we need response headers; what purpose should they serve? Once we see clearer, we can then identify the cost-optimal implementation. Value I've seen so far are: - Reflecting the preference of the user to identify transmission errors - Communicating the choice of the server whether to comply with a DNT preference or not - Determining whether a server understood a preference or not. Are there values that I've overlooked? Another discussion to have is the scope of responses: Do we want the server choices to be a fixed value for a site or unique subsets or requests? Regards, matthias On 10/11/2011 10:13 PM, JC Cannon wrote: > We think the topic of a response to the DNT header will require a fair > amount of further discussion. We think that a number of other issues > should be resolved first before we can reach a consensus on whether it > should be sent and what it means. Here are some specific concerns: > > > > COST OF IMPLEMENTATION > > > > While most web server environments do make it simple to return a HTTP > header as part of the response, integrating a way to return such a > header into existing systems isn’t necessarily straightforward. Some > systems used today to combine web requests with information known > about the user to form targeted responses and do not allow for an easy > way to derive what opt-ins are in place and why the response is the > way it is. A response header that indicates what the service saw in > the DNT request AND how it was processed is not always a trivial > engineering exercise. > > > > VALUE OF IMPLEMENTATION > > > > Today browsers are consistently moving in the direction of less and > less user interface, reducing the number of choices users must make to > experience the web, and trying to make smart choices on behalf of the > user. It’s not immediately obvious that all browser vendors will want > to process a DNT response and take any action. Before we can truly > evaluate the benefit of a response, we should have a clearer idea of > what browser vendors want to do with this information. There is little > benefit to the community in requiring online services to invest in > being able to return a response if the value is then ignored. > > > > WHEN TO RETURN A RESPONSE > > > > To fullyunderstand the benefit of a response, we need to understand > when a response would be required. If we conclude too early that a > response is required we run the risk of creating reasons to have some > kind of value and potentially making the response more and more > complex. Perhaps a good resolution at this point is to agree that > nobody believes having a response is detrimental but until we address > some of the other questions before us (e.g. first party vs. third > party) it will be hard to demonstrate that the cost is worth the benefit. > > > > INCREASED LOAD ON WEB SERVERS > > > > We share Roy’s concerns [1] about additional load on servers and > content caches. > > > > [1] http://lists.w3.org/Archives/Public/public-tracking/2011Oct/0047.html > > > > JC > > Twitter <http://twitter.com/jccannon7> > > > -- Dr. Matthias Schunter, MBA IBM Zurich Research Laboratory, Ph. +41 (44) 724-8329 Homepage: www.schunter.org, Email: schunter(at)acm.org PGP Fingerprint 989AA3ED 21A19EF2 B0058374 BE0EE10D
Received on Tuesday, 11 October 2011 22:41:58 UTC