Re: tracking-ISSUE-81: Do we need a response at all from server?

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