RE: TIBCO objects to last call (resend)

David,

 

I really do think we are coming at this from different points of view.  

 

I assert that extensibility exists with the existing MAPs.  I assert
this understanding the SOAP extensibility model and the lack of
constraints on re-using MAPs.  I then believe that I do not have to
provide any number of scenarios showing that the extensibility exists.
Roughly speaking, my pov is "It's designed correctly, prove me wrong".

 

You hear my assertion, but then ask for it to be proven.  When I say
it's extensible, you're not sure.  For example, you say "there is a
burden to prove that it will work...".  Roughly speaking, your pov is
"If it's designed correctly, prove it".

 

In general, I believe the burden of proof and effort is upon those
raising issues to prove that there is an issue.  For example, if person
X asserts that specs x,y,z compose, then I better show a scenario where
they don't compose if I want to object to the assertion.  

 

You are effectively demanding that I prove something that I believe in,
and you are not offering any proof that my belief is mistaken.

 

Do you agree with my rough assessment of the points of view and
expectations we have on burden of proof?   

 

Can you see why I think that you need to provide some proof that the
extensible assertion is invalid, especially given that I know you are
intimately familiar with WS-A extensibility and other forms of MEPs?

 

Cheers,

Dave

 

  _____  

From: David Hull [mailto:dmh@tibco.com] 
Sent: Thursday, March 24, 2005 11:06 AM
To: David Orchard
Cc: public-ws-addressing@w3.org; Mark Nottingham
Subject: Re: TIBCO objects to last call (resend)

 

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.