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RE: LC 76 - What makes a msg WS-A?

From: David Orchard <dorchard@bea.com>
Date: Thu, 14 Jul 2005 13:09:41 -0700
Message-ID: <32D5845A745BFB429CBDBADA57CD41AF112D08F8@ussjex01.amer.bea.com>
To: "Martin Gudgin" <mgudgin@microsoft.com>, "David Hull" <dmh@tibco.com>
Cc: "Katy Warr" <katy_warr@uk.ibm.com>, <public-ws-addressing@w3.org>
There's two ways of looking at it:

1. The client is messed up because it can't send a properly formatted
WS-A Request, in which case maybe the service should fault.

2. The client is messed up but neither client nor server really cares if
the Addressing processing isn't invoked.

 

Dave

 

 

 

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From: Martin Gudgin [mailto:mgudgin@microsoft.com] 
Sent: Thursday, July 14, 2005 12:34 PM
To: David Orchard; David Hull
Cc: Katy Warr; public-ws-addressing@w3.org
Subject: RE: LC 76 - What makes a msg WS-A?

 

I'm not convinced that it matters. I'm not even sure it's necessary that
a given service be consistent in this particular case... But assuming
that a given service was consistent, surely it could choose either
behaviour?

 

Gudge

 

	
  _____  


	From: David Orchard [mailto:dorchard@bea.com] 
	Sent: 14 July 2005 20:24
	To: Martin Gudgin; David Hull
	Cc: Katy Warr; public-ws-addressing@w3.org
	Subject: RE: LC 76 - What makes a msg WS-A?

	The dead cat joke, I love it.  

	 

	You are right, let's have the wsa:ReplyTo marked mU="false".  

	 

	Fault or no fault my friend?

	 

	Dave

	 

	
  _____  


	From: Martin Gudgin [mailto:mgudgin@microsoft.com] 
	Sent: Thursday, July 14, 2005 12:03 PM
	To: David Orchard; David Hull
	Cc: Katy Warr; public-ws-addressing@w3.org
	Subject: RE: LC 76 - What makes a msg WS-A?

	 

	I'd be tempted to have my service try to look in the box to see
if the cat was dead or not...

	 

	How do I have both headers marked mU='false' when one of them
doesn't appear in the message?

	 

	Gudge

		 

		
  _____  


		From: David Orchard [mailto:dorchard@bea.com] 
		Sent: 14 July 2005 20:02
		To: Martin Gudgin; David Hull
		Cc: Katy Warr; public-ws-addressing@w3.org
		Subject: RE: LC 76 - What makes a msg WS-A?

		+1 to the cases you mentioned, but there's more to it
than that methinks.

		 

		The boundary case I think is where there's an endpoint
that understands WS-A AND understands non-WS-A messages.  What triggers
it to apply WS-A rules, such as when to generate Faults, when messages
aren't marked mU="true".  Say that there is a wsa:ReplyTo and no
wsa:Action, and they are both marked mU="false".  The node could either
ignore the WS-A header blocks or generate a Fault. 

		 

		Dave 

		 

		 

		
  _____  


		From: public-ws-addressing-request@w3.org
[mailto:public-ws-addressing-request@w3.org] On Behalf Of Martin Gudgin
		Sent: Thursday, July 14, 2005 11:04 AM
		To: David Hull
		Cc: Katy Warr; public-ws-addressing@w3.org
		Subject: RE: LC 76 - What makes a msg WS-A?

		 

		OK, I'm confused.

		 

		Why do you conclude that the answer to my question
"Given that the wsa:Action header is mandatory, isn't it the presence of
that header?" is 'No'. 

		 

		I would have come to the opposite conclusion;

		 

		I have an endpoint that understands WS-Addressing. It
receives a message that contains wsa:ReplyTo but no wsa:Action. It
generates a fault. Seems pretty straightforward to me.

		 

		I have an endpoint that doesn't understand
WS-Addressing. It receives a message that contains one or more wsa:
headers, it either ignores them or generates a mustUnderstand fault
depending on whether those headers are marked mustUnderstand='true' or
not. Again, seems pretty straightforward to me.

		 

		Gudge

			 

			
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			From: David Hull [mailto:dmh@tibco.com] 
			Sent: 14 July 2005 18:02
			To: Martin Gudgin
			Cc: Katy Warr; public-ws-addressing@w3.org
			Subject: Re: LC 76 - What makes a msg WS-A?

			Martin Gudgin wrote: 

			 

				 

				
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				From: David Hull [mailto:dmh@tibco.com] 
				Sent: 14 July 2005 16:32
				To: Martin Gudgin
				Cc: Katy Warr;
public-ws-addressing@w3.org
				Subject: Re: LC 76 - What makes a msg
WS-A?

				Is this really a question of how to
support both WSA and old-style HTTP requests on the same endpoint?  
				[MJG] I don't know, I didn't ask the
original question.

			Hmm ... my message was in-reply-to yours, but
the question was really aimed more at Katy.  Maybe we need BPEL here
:-).

				
				  I.e., if I don't see any WSA headers
at all, I assume it's an old-style request and act accordingly, but if I
see anything WSA, I follow the rules in section 3? 
				[MJG] I guess one could do that... 

			Well, one should do something to ensure that
old-style requests are accepted as such.

				
				The tricky bit is that, since MAPs like
[destination] and [reply endpoint] can default, a message with no wsa:
elements on the wire could still be assigned values for some of its
MAPs, since the infoset will still have values for the corresponding
elements. 

				[MJG] Which Infoset are you talking
about? The XML Infoset has no such values.

			Sorry, I didn't get that quite right.  I was
going by section 3.2, particularly the descriptions of wsa:To:

			This OPTIONAL element (whose content is of type
xs:anyURI) provides the value for the [destination] property. If this
element is NOT present then the value of the [destination] property is
"http://www.w3.org/@@@@/@@/addressing/anonymous"
<http://www.w3.org/@@@@/@@/addressing/anonymous> .

			
			(and similarly for wsa:ReplyTo). I initially
misread this as stating that the element defaulted, as opposed to the
MAP.  So s/since the infoset will still have values for the
corresponding elements/since the properties are defaulted in the absence
of the corresponding elements in the infoset/.  This sort of confusion
could be seen as an argument against the two-layered approach (or simply
as an argument that I read too quickly).
			
			In any case, you can't simply look at the
abstract properties and say "some WSA properties are defined, so it's a
WSA message".

				
				   So either we have to drop down to
look at the infoset level, and in particular at the non-defaulted
elements in the infoset, or we have to find some marker that can't be
defaulted away.  This is why the [action] property looks significant
here.  But on the other hand, what if I include a wsa:ReplyTo element
and no action?  By the "it's WSA iff [action] is present" rule, that's
not a WSA message and therefore not an error.  This seems wrong. 
				[MJG] Why does it seem wrong?

			It seems wrong not to fault for a message that
contains a wsa:ReplyTo on the wire but not a wsa:Action.

				
				Put another way, when would one get a
fault for omitting [action]? 
				[MJG] Whenever another wsa: header is
present in a message.

			In other words, the answer to your question
("Given that the wsa:Action is mandatory, isn't it the presence of that
header?") is "No."
			
			This is why at the Berlin meeting we tried to
make sure that all the possibilities were covered for various
combinations of the MAPs.  I believe we've satisfied ourselves that they
are, but perhaps we need to revisit this work?

				
				
				Martin Gudgin wrote: 

				Given that the wsa:Action is mandatory,
isn't it the presence of that header?

				 

				Gudge

				 

				
  _____  


				From:
public-ws-addressing-request@w3.org
[mailto:public-ws-addressing-request@w3.org] On Behalf Of Katy Warr
				Sent: 14 July 2005 16:07
				To: public-ws-addressing@w3.org
				Subject: LC 76 - What makes a msg WS-A?

				
				Please could we discuss the following in
the context of LC76? 
				
				When is an incoming message deemed to be
a WS-Addressing message and therefore subject to the appropriate
WS-Addressing validation?   Is it based on the presence of any
WS-addressing Message Addressing Property?  For example, does a message
containing a reference parameter (but no other WS-Addressing
information) need to result in a MessageAddressingHeaderRequired?    Or,
for example, does the declaration of the wsa namespace rendor the
message WS-Addressing? 
				
				Thanks 
				Katy

				 

			 
Received on Thursday, 14 July 2005 20:09:55 GMT

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