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Re: TIBCO objects to last call (resend)

From: David Hull <dmh@tibco.com>
Date: Thu, 24 Mar 2005 14:05:31 -0500
To: David Orchard <dorchard@bea.com>
Cc: public-ws-addressing@w3.org, Mark Nottingham <markn@bea.com>
Message-id: <42430F7B.8000909@tibco.com>
There is a basic and somewhat long-standing disconnect here that I'm 
still trying to understand.

To me, and I suspect you may agree, WSN and WSE are not extending MAPs 
in any way.  They are simply using EPRs.  They would work equally well 
if section 3 were deleted from WSA entirely.  "You can build things with 
EPRs" -- a true and useful statement as far as I can tell -- is not the 
same as "you can extend MAPs".  Neither is the same as the pertinent 
question of "can we support MEPs beyond request/reply as easily as we 
support request/reply?"

Section 3 contains specific support for request/reply and we reference 
this directly in the WSDL binding document.  This creates a presumption 
that specific support for MEPs is required in the MAPs.  There are 
several ways to get beyond this:

   1. Remove special mention of reply and fault from the MAPs and re-do
      the WSDL document accordingly.  This would show that no specific
      support is needed, request/reply serving as an example.  I'm
      currently leaning toward this, provided that someone will sign up
      to helping re-do the WSDL binding.  I'm told -- and I'm not being
      facetious here -- that it wouldn't be hard.
   2. Provide general support in the MAPs for all kinds of endpoints and
      re-do the WSDL document accordingly.  The proposals 1 and 4 we
      voted on, along with a couple of others that have appeared, are
      aimed at this.  This would also show that no specific support is
      needed, request/reply again serving as an example.
   3. Keep the status quo, but provide specific examples of MEPs that do
      not rely on the pre-defined reply and fault endpoints, then verify
      that these are no harder to produce or use than the current
      request/reply.  I don't think this would be optimal, but it would
      be good enough.  If we want to keep the status quo, there is a
      burden to prove that it will work in cases other than those it is
      specifically tailored to.
   4. Remove MAPs from WSA entirely in favor of discussing MEPs directly
      in terms of EPRs, message IDs and such.  No MAPs, no MAP
      extensibility issue.  Extensibility comes directly from SOAP,
      which we all agree to be extensible.  Once again, request/reply
      serves as an example.
   5. Keep the status quo and make it as explicit as possible that we
      have not really addressed how to cover non request/reply MEPs, and
      hope no one minds.  Proposals 2 and 3 that we voted on are steps
      in this direction.

I'm frankly puzzled by the notion -- as I understand it -- that it's 
enough to simply assert extensibility without providing any example of 
how it would work.

David Orchard wrote:

> David,
> I am sympathetic to your concerns.  I have a particular interest in 
> ensuring that extensibility by 3rd parties is enabled for a large 
> variety of scenarios.  I respect the amount of work that you have done 
> in articulating the concerns you have.
> However, I think that you have not done the right work in this regard. 
>  To me, the "smoking gun" for not going to last call is a scenario 
> where the MAPs are not extensible.  You have listed a variety of 
> scenarios, but you haven't proven that a single one of those cannot be 
> covered with WS-A + extensibility.  As you are a smart fellow, this 
> seems surprising to me. 
> I don't think that the burden of proof should be upon people like 
> myself to prove that the MAPs are extensible.  I'm pretty convinced 
> they are, as we have used these in other specifications like 
> WS-ReliableMessaging and WS-Eventing, and I'm sure you have in 
> WS-Notification.  Given that there is existent use of WS-A in broader 
> MEPs, I really do think that a "smoking gun" is required to hold up 
> last call.  
> If you had provided a concrete scenario that extends the MAPs and 
> showed how the spec was not extensible/broken, I would be totally with 
> you in not going to LC.  
> As it stands, your comments are specific and worthy questions, but do 
> not show to me anything that should prevent us from saying "Dear 
> Larger Community (pun on LC), we think we are done, did we goof up 
> anywhere?".
> Cheers,
> Dave
> ------------------------------------------------------------------------
> *From:* public-ws-addressing-request@w3.org 
> [mailto:public-ws-addressing-request@w3.org] *On Behalf Of *David Hull
> *Sent:* Wednesday, March 23, 2005 4:52 PM
> *To:* public-ws-addressing@w3.org
> *Cc:* Mark Nottingham
> *Subject:* TIBCO objects to last call (resend)
> This message details TIBCO's reasons for objecting to the 
> WS-Addressing core and SOAP binding documents going to last call.  
> There are several specific reasons, all of which center around the 
> Message Addressing Properties (hereafter referred to as MAPs), and 
> particularly around issues i050 and i054, which we consider to have 
> been closed hastily.  We have no objection to the current formulation 
> of EPRs and indeed believe that WS-Addressing would provide 
> considerable value on the basis of EPRs alone.
> We have made our opposition to the current resolution of i054 known 
> and have formally voted against this resolution.  We are prepared to 
> formally object to the core and SOAP binding specifications as they 
> currently stand on the basis of this issue.  We also note that a new 
> proposed resolution for this putatively closed issue has appeared 
> since the vote concerning last call was taken. 
> Whatever the final resolution of i050 and i054, there currently remain 
> significant questions as to the meaning of MAPs in the specification.  
> Many such questions, including those relating to the objections above, 
> have been raised in public discussion over the past two weeks but have 
> so far gone unanswered.  It is our opinion that several of these 
> questions are of such a nature that if there is any significant doubt 
> concerning them the specification is not sufficiently well-defined to 
> be useful.  We do not claim that none of them can be answered, and in 
> fact we hope that many of them can be answered quickly.  However, 
> until they are, we cannot consider the discussion of the specification 
> to be materially complete and cannot recommend putting the document 
> out for public comment.
> These questions include
>     * Whether the MAPs are considered to contain only those properties
>       defined in the WS-Addressing specifications or whether other
>       specifications may amend them
>     * If other specifications can amend this set, in what sense may it
>       be said to be specified by WS-Addressing
>     * Exactly how a future specification requiring endpoints beyond
>       the presently defined reply and fault endpoints should define these
>     * In particular whether such a specification would have to define
>       a new SOAP module to hold properties parallel to those defined
>       in the MAPs
>     * How the current definition of MAPs as mandatory properties would
>       apply to existing SOAP/HTTP interactions which have no notion of
>       such properties
>     * Whether existing specifications would need to be amended to
>       mention MAPs and/or their corresponding headers in order to
>       leverage the asynchronous request/reply pattern to which the
>       MAPs are evidently tailored, as suggested by the explicit
>       mention of ReplyTo and other headers in specifications such as
>       WS-Transfer and WS-Enumeration
>     * What level of MAP extensibility is actually required by the
>       WS-Addressing charter.
> Please consider this listing as a request to open these outstanding 
> questions as formal issues.
> While we understand and indeed share the desire of the group to get to 
> last call as quickly as reasonably possible, given the current state 
> of the specification and the discussion around it, we regret to say 
> that we cannot support the documents going to last call at this point, 
> and so must object.
Received on Thursday, 24 March 2005 19:06:08 UTC

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