Subject: RE: ERR header (NEW ISSUE: Drop Content-Location)

From: "Joris Dobbelsteen" <[email-masked]>
Date: Thu, 30 Nov 2006 00:15:56 +0100

>-----Original Message-----
>From: [email-masked] 
>[mailto:[email-masked]] On Behalf Of Henry Story
>Sent: woensdag 29 november 2006 23:19
>To: Henrik Nordstrom
>Cc: Roy T. Fielding; Anne van Kesteren; HTTP Working Group
>Subject: Re: NEW ISSUE: Drop Content-Location
>
[snip]
>
>Could that be solved my creating a ERR method, so that clients 
>could send feedback to servers at the resource they found wanting?
>
>------------------
>ERR /page0 HTTP...
>...
>
>Your Content-Location is broken see spec xyz
>------------------
>

This feature was discussed before.
See <http://lists.w3.org/Archives/Public/ietf-http-wg/2004AprJun/>.
Also see <http://www.imc.org/atom-syntax/mail-archive/msg05546.html> for
somewhere in a discussion.

I personally think this is a bad idea.

The most important reaon for this is that the ERR reporter *must* be
guarenteed to have correctly implemented the specifications. Thus it
should not contain bugs and certainly not generate incorrect reports.
I'm also wondering how future revisions of the spec might affect current
deployments that would have such a feature.
Unless this issue can be solved it seems an inappropriate feature.

Other reasons against it are:

(1) The issue is put by the administrator of the system, rather than the
developers of the proxy. It generates extra bandwidth and administrative
overhead for owners of web servers (massive error requests).
(2) How would you blame an specification violating system in-between,
such as a proxy server?
(3) It increases server load without any likelyness of solving the
problem anytime soon. That would be up to the implementor and their
priorities.
(4) It does not prevent specification ambiguities. This leads to dirty
implementation hacks in the hope the spec would follow or at least
reduce errors. The spec has a very slow release cycle, it takes at least
several months before the spec is updated.

Of course there are good reasons to support it:

(A) It creates more momentum to keep non-conforming servers up to their,
hopefully better, latest versions and specification conformance.

My suggestion:
An official test suite.
Ideally it would be possible to extract the rules immediately from the
specs. Maybe the specification should use symantics that could be
automatically proven ;)

This is just my opinion...

- Joris