Re: 2NN Contents Of Related (303 Shortcut)

[Mark Nottingham <[e-mail]>]

Eric,

We’re happy to discuss it here, but can’t commit to a schedule before that discussion has begun. 

For my part, I’m still not sure what the difference between the proposed status code is from 200 + Content-Location.

Cheers,


On 26 Aug 2014, at 10:11 am, Eric Prud'hommeaux <[e-mail]> wrote:

> I understand people are busy, but is there a chance we can move forward
> on this? The subject has been extensively discussed on
> www-tag (as detailed below). The June I-D is at:
> http://tools.ietf.org/html/draft-prudhommeaux-http-status-2nn-00
> 
> Technical Summary:
> [[
> 2NN provides a shorcut the GET X->303 Location:Y, GET Y->200 pattern.
> For responses where the server would have responded with a Location
> header, it can instead respond with the payload of a notional GET on
> that location. The notional GET has all of the headers of the original
> request. This defines the behavior for conneg, Vary headers, caching,
> etc.
> ]]
> 
> There's a fairly thorough summary in the TAG's draft review:
> https://github.com/w3ctag/spec-reviews/blob/master/2014/04/http-209.md
> The issues in that document have been addressed in the I-D, but it
> does contain motivation for 2NN (especially with respect to Server
> Push).
> 
> The urgency here is that the W3C Linked Data Platform (LDP) Working
> Group, which first surfaced the need for this, will be ready to issue
> its formal "Call for Implementations" in mid-September.  At that
> point, people outside the LDP Working Group will begin writing code
> that uses this response code.
> 
> I understand there may still be some concerns. In the next few weeks,
> we'd like to try to address them or resolve that they are truly
> insurmountable. Is that reasonable?
> 
> I went throught the www-tag archives and added my own summary,
> underneath, for each message:
> -------------------------------------------------------------------------
> A new HTTP response code say 209                Dec 19 Tim Berners-Lee
> │                   use case for a 209
> ├─>Re: A new HTTP response code say 209         Dec 19 Daniel Appelquist
> │                   London f2f logistics
> ├─>Re: A new HTTP response code say 209         Dec 19 Julian Reschke
> │ │                 299 as placeholder
> │ │                 why not 303 or 202?
> │ └─>                                           Dec 20 Tim Berners-Lee
> │                   payload conflict of 303
> │                   202 for asynchronous
> │                   303 fine logically but requires round trip
> ├─>Re: A new HTTP response code say 209         Dec 20 Mark Nottingham
> │ │                 use media type instead?
> │ │                 HTTPbis 8.2.2.  Considerations for New Status Codes
> │ └─>                                           Jan 09 Henry Story
> │   │               media types describe representation, not resource
> │   ├─>                                         Jan 09 Henry S. Thompson
> │   │ │             define in terms of 303+200
> │   │ ├─>                                       Jan 09 Henry Story
> │   │ │ │           +1 but propose 3xx instead of 2xx
> │   │ │ └─>                                     Jan 09 David Sheets
> │   │ │   │         respond with message/http
> │   │ │   ├─>                                   Jan 09 David Booth
> │   │ │   │ │       broaden 209 to cover 300, 301, 302 and 307
> │   │ │   │ └─>                                 Jan 09 David Booth
> │   │ │   │         or 300, 301, 302 or 307 + multipart body
> │   │ │   └─>                                   Feb 13 Reto Gmür
> │   │ │             confuses clients interpreting 2xx as 200
> │   │ │             could work in 303
> │   │ ├─>Fwd: A new HTTP response code say 209  Jan 09 Jonathan A Reese
> │   │ │             no evidence that 200 has intended semantics in practice
> │   │ └─>                                       Jan 09 Julian Reschke
> │   │   │           use 3xx code. 2xx response would apply to request-URI
> │   │   └─>                                     Jan 09 Henry S. Thompson
> │   │     │         Content-location understood wrt conneg
> │   │     └─>                                   Jan 09 Julian Reschke
> │   │       │       says there's a more specific URI
> │   │       └─>                                 Feb 10 Ashok Malhotra
> │   │         │     Arwe: propose: 303 + Prefer: return=representation
> │   │         └─>                               Feb 13 Yves Lafon
> │   │               dangerous, changes 303, would need Vary: Prefer. 2xx more applicable
> │   └─>                                         Jan 09 Julian Reschke
> │                   wording of 303
> ├─>Re: A new HTTP response code say 209         Dec 19 Jonathan A Reese
> │                   note http://www.w3.org/2001/tag/doc/urls-in-data-2013-04-27/
> └─>draft of                                     Feb 24 Eric Prud'hommeaux
>  │                 draft <http://localhost/2014/02/2xx/draft-prudhommeaux-http-status-209>
>  ├─>Re: draft of 209 proposal                  Feb 24 David Booth
>  │ │               URL correction
>  │ └─>                                         Feb 24 Eric Prud'hommeaux
>  │   │             ack
>  │   └─>                                       Mar 17 Julian Reschke
>  │     │           Conflates "see elsewhere" with "too large", how can client know which applies
>  │     └─>                                     Mar 17 Eric Prud'hommeaux
>  │                 all that HTTP cares is that the client requested X and got something other than X
>  └─>                                           Mar 07 Mark Nottingham
>    │               why is 209 better than 200 with Content-Location for e.g. POST->303 and GET->303?
>    │               partial feeds is addressed in RFC5005
>    │               how does HTTP software behave differently?
>    ├─>                                         Mar 07 Julian Reschke
>    │               offer to help submit I-D
>    ├─>                                         Mar 07 Eric Prud'hommeaux
>    │ │             GET->303 requires a round trip
>    │ │             RFC5005 re-uses URL for a page of resource. requires syndication format (Atom)
>    │ │             ack, same-origin constraint insufficient for shared caches
>    │ ├─>                                       Mar 08 Julian Reschke
>    │ │             submit I-D via http://www.ietf.org/id-info/
>    │ ├─>                                       Mar 08 Jeni Tennison
>    │ │             TAGs use of URLs http://www.w3.org/TR/urls-in-data/ includes 303s
>    │ └─>                                       Mar 13 Mark Nottingham
>    │   │           not really a redirect so 200 with Content-Location should suffice
>    │   │           RFC5005 doesn't require URL re-use
>    │   │           why not embed paging info in served representations?
>    │   ├─>                                     Mar 13 Jonathan A Rees
>    │   │ │         Content-Location is a representation of requested resource
>    │   │ ├─>                                   Mar 16 Mark Nottingham
>    │   │ │ │       more details [on why Content-Location won't suffice]
>    │   │ │ └─>                                 Mar 15 Jonathan A Rees
>    │   │ │         [discussion of non-information resources]
>    │   │ └─>                                   Mar 17 Julian Reschke
>    │   │   │       is it OK that naive clients will treat 209 as 200?
>    │   │   └─>                                 Mar 17 Eric Prud'hommeaux
>    │   │           small survey examining behavior of such clients
>    │   └─>                                     Mar 15 Eric Prud'hommeaux
>    │     │         example differentiating page of resource from representation of resource
>    │     └─>                                   Mar 16 Mark Nottingham
>    │               HTTP doesn't enable one representation to make an authoritative assertion about another
>    └─>                                         Mar 07 Sandro Hawke
>      │             propose same-origin requirements for trusting 209 response
>      └─>                                       Mar 07 Eric Prud'hommeaux
>                    there are apparently different security reqs for client vs. proxies
>                    proxies may not be content with same-origin, client proxies likely more liberal
> 
> I believe Mark Nottingham remains concerned that 2NN's assertion about
> the representation of the Location resource is counter to HTTP.  The
> Linked Data Platform's paging spec presumes that clients will take
> advantage of the improved efficiency.
> -- 
> -ericP
> 
> 
> * Julian Reschke <[e-mail]> [2014-06-30 19:40+0200]
>> (FYI)
>> 
>> 
>> -------- Original Message --------
>> Subject: I-D Action: draft-prudhommeaux-http-status-2nn-00.txt
>> Date: Mon, 30 Jun 2014 09:08:17 -0700
>> From: [e-mail]
>> Reply-To: [e-mail]
>> To: [e-mail]
>> X-ArchivedAt: http://www.w3.org/mid/[e-mail]
>> 
>> 
>> A New Internet-Draft is available from the on-line Internet-Drafts
>> directories.
>> 
>> 
>>        Title           : The Hypertext Transfer Protocol (HTTP)
>> Status Code 2NN (Contents of Related)
>>        Author          : Eric G. Prud'hommeaux
>> 	Filename        : draft-prudhommeaux-http-status-2nn-00.txt
>> 	Pages           : 9
>> 	Date            : 2014-06-30
>> 
>> Abstract:
>>   This document specifies the additional HyperText Transfer Protocol
>>   (HTTP) Status Code 2NN (Contents of Related).  It also specified a
>>   Prefer header value "contents-of-related" which clients can use to
>>   indicate that they can accept 2NN responses.
>> 
>> 
>> The IETF datatracker status page for this draft is:
>> https://datatracker.ietf.org/doc/draft-prudhommeaux-http-status-2nn/
>> 
>> There's also a htmlized version available at:
>> http://tools.ietf.org/html/draft-prudhommeaux-http-status-2nn-00
>> 
>> 
>> Please note that it may take a couple of minutes from the time of submission
>> until the htmlized version and diff are available at tools.ietf.org.
>> 
>> Internet-Drafts are also available by anonymous FTP at:
>> ftp://ftp.ietf.org/internet-drafts/
>> 
>> _______________________________________________
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>> or ftp://ftp.ietf.org/ietf/1shadow-sites.txt
>> 
>> 
>> 
>> 
> 
> -- 
> -ericP
> 
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--
Mark Nottingham   http://www.mnot.net/