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Follow-up to Question on CR33

From: Doug Davis <dug@us.ibm.com>
Date: Thu, 14 Sep 2006 02:52:48 -0400
To: public-ws-addressing@w3.org
Message-ID: <OF689EBFB2.F70D1F61-ON852571E9.002413A8-852571E9.0025CA89@us.ibm.com>
After some off-line chats I realized that I may need to elaborate on why I 
came to the conclusion that this solely a WSA issue and why there's this 
implicit restriction that no other WS-* spec can define a new special 
non-addressable URI.  Let's examine the following use-case:

- a server only supports sync responses - so it can support "anon", "none" 
and "foo" replyTo's.  'foo' is a new magic URI that some spec defined 
- client A only knows about WSA 
- client B knows about WSA and WS-foo 
- the server, knowing it wants to tell people it can only support sync 
responses adds the wsaw:Anonymous="required" wsdl marker 

Client A sees that marker and sets replyTo to 'anon' - all is ok 
Client B knows that the server supports WS-foo, but the wsaw:Anonymous 
marker says only "anon" and "none" are supported
Support for Client B + WS-foo appears to be restricted.

Even if the server adds another wsdl marker that say "replyTo can be foo" 
- what is client B supposed to do when it sees conflicting wsdl markers? 
The server can not set wsaw:Anonymous to 'optional' because that mean that 
clients can pass in "www.ibm.com"  - which isn't what the server wants. 
What can the server put in its WSDL to get the desired results?

Its because I don't know the answer to these questions that I come to the 
conclusion that the use of wsaw:Anonymous="required" implicitly means that 
no other WS-* spec can do what WSA has done and define a new 
non-addressable URI for use in the replyTo and faultTo headers.  And, I 
think this makes it a WSA issue and not an RM issue - RM is just the first 
unlucky WS-* spec to expose this problem.  :-)


Doug Davis/Raleigh/IBM@IBMUS 
Sent by: public-ws-addressing-request@w3.org
09/13/2006 09:52 AM


Question on CR33

After Monday's conf call I was thinking about the "status quo" option and 
I was wondering about the implications of that.  As currently worded, the 
wsaw:Anonymous=required option would prevent someone from using any URI in 
wsa:ReplyTo except "anonymous".  This is a bit too restricted because WSA 
itself, during its work on the spec, found the need to define another 
non-addressable URI: "none".  I believe there was some other CR which was 
adopted to loosen the wording a bit to allow for this special case.  So, 
the question that I keep trying to come to terms with is whether or not 
the WG is aware of the implicit restriction of the "status quo" option. 
What it basically means is that no other WS-* spec can ever define its own 
non-addressable URI to be used in wsa:ReplyTo when this WSDL marker is 
used.  Ever.  Ignore RM, or another variant of a URI that means 'the 
backchannel'.  What if some other spec wanted to do exact what WSA did and 
define a new URI to mean something special - e.g. like 'none' means 'trash 
it'?  They can't do it.  Because the semantics of this wsdl marker are 
tied to specific URI values (and, as of now, this list isn't extensible) 
and not to whether or not the server is willing/able to send async 
responses, WSA has in essence banned other specs from doing exactly what 
it itself has found a need to do: extend the list of 'special URIs'. While 
this is obviously an option, is it really the intent of the WG to not 
allow this flexibility for future specs? 

Received on Thursday, 14 September 2006 06:52:53 UTC

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