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RE: [SOAP-JMS] minutes 2008-05-20

From: Peter Easton <peaston@progress.com>
Date: Thu, 22 May 2008 18:17:57 -0400
Message-ID: <3712271BEF30D74CBEA9E827CD9ABDBD017E07B0@MAIL03.bedford.progress.com>
To: "Eric Johnson" <eric@tibco.com>
Cc: "Amelia A Lewis" <alewis@tibco.com>, <public-soap-jms@w3.org>
Hi Eric,
 
Obviously I'm not getting something basic here - so please bear with me.

 
Are you are talking about JMS 1.1 message selectors? If so, who in this
case is setting the selector ?
 
In this setup the tester at F is a pure JMS client that had better be
listening on the right destination with no restrictive selectors. 
 
Peter

________________________________

From: Eric Johnson [mailto:eric@tibco.com] 
Sent: Thursday, May 22, 2008 5:52 PM
To: Peter Easton
Cc: Amelia A Lewis; public-soap-jms@w3.org
Subject: Re: [SOAP-JMS] minutes 2008-05-20


Hi Peter,

Peter Easton wrote: 

	
	Eric can you explain this. Are you saying the JMS Server is
removing JMS properties before client delivery at F ?

Sorry, I thought the context of using "Filters" made this statement
clear.  What I mean is that when filters are applied, the server may
never deliver the message to (F), because (E) determines that (F) isn't
wanting to see the message.  If we had a well-defined way to check the
message either as it arrives at (E) the server, or while it is at
server, this wouldn't be a particularly big deal.  Of course, JMS
doesn't give us that, though, which means that we can only check the
message as or before it is delivered to (D).

-Eric.


	 
	"We've gone through great pains in the specification to make
certain characteristics of a SOAP message visible as properties of the
message itself, so, for example, listeners could set up filters on the
server looking for certain properties on the message.  So testing for
conformance at "F" is actually too late - by the time that a message has
arrived at "F", the properties already need to be set on the message."
	 

________________________________

	From: public-soap-jms-request@w3.org
[mailto:public-soap-jms-request@w3.org] On Behalf Of Eric Johnson
	Sent: Thursday, May 22, 2008 5:00 PM
	To: Amelia A Lewis; public-soap-jms@w3.org
	Subject: Re: [SOAP-JMS] minutes 2008-05-20
	
	
	Hmmm, I've been puzzling over this, trying to figure out what
the right answer is, as the messages scroll by.
	
	Naturally enough, I pretty much agree with my co-worker Amy.
The only way we can test conformance is via the JMS APIs.  I think this
discussion has accidentally veered into quite interesting territory - as
near as I can tell, we may not be arguing about *how* to test
conformance, per-se, but about *where* we test for conformance, or, more
formally, what are the conformance targets of the specification?
	
	Doing a really bad ASCII diagram, suppose my use case is a Java
service using SCA or JAX-WS to send a message to a remote SCA or JAX-WS
Java client, using SOAP over JMS.
	
	(A)Applicaton --> (B)data binding layer --> (C)SOAP processing
stack --> (D) JMS provider client -->  (E) JMS server --> (F) JMS
provider client --> (G) SOAP processing stack --> (H) data binding -->
(I) Application
	
	If I follow this correctly, I believe Phil is arguing that we
test for conformance between (F) & (G), and only there.  Whereas, I
think Amy and (now) I are arguing that we should also test between (C) &
(D).
	
	I think there are two reasons for this.  One reason comes from
an assumption hidden above, which is that there may not be any step (G).
We've gone through great pains in the specification to make certain
characteristics of a SOAP message visible as properties of the message
itself, so, for example, listeners could set up filters on the server
looking for certain properties on the message.  So testing for
conformance at "F" is actually too late - by the time that a message has
arrived at "F", the properties already need to be set on the message.
However, since everything that happens between entering (D), and leaving
(F) is proprietary, we have no way to test what goes on there.
	
	The second problem comes from the notion of a conforming SOAP
stack - does it get to make assumptions about using extensions to the
JMS API?  That is, do we expect that the conforming SOAP stack will need
to work with *any* JMS provider, so almost by definition, the only
portable way it can work is via straight JMS APIs.  We can postulate the
existence of a SOAP stack that happens to know how to take advantage of
some proprietary extension from vendor X, maybe for performance or
security or some such thing.  Just for a completely made-up example, I
could extend the JMS API to somehow "secure" the value of the properties
that I set on a message, but to do so, I have to call a vendor API, not
one of the standard ones.
	
	If that's the kind of scenario that Phil is trying to address, I
that leaves us with a question.  When we test at the point between C &
D, how do we do it?  I can think of three approaches:
	

	*	Write a "mock" JMS provider - messages never go
anywhere, but can be checked for correctness 
	*	Write a JMS provider that wraps another JMS provider
with pure JMS APIs.
		
	*	Extend the above with the use of dynamic proxies, so
that we can pass along calls to proprietary methods to the underlying
implementation. 
	*	Require SOAP stacks going through conformance testing to
provide a hook, whereby the message they're about to send can be
checked. 

	The first two approaches would prevent any conformance test
target from detecting and using extension APIs, and thus would verify,
even for a vendor that happens to support extensions from specific
providers, that they would also happen to be conformant.  I also came to
the conclusion that the dynamic proxies approach would likely be
complicated, and probably still fail.  The wrapped JMS provider approach
might work, but I've not considered the scope of work there.  The "hook"
approach would be straightforward, but it intrudes on the SOAP/JMS
provider stack.
	
	-Eric.
	
	Phil Adams wrote: 


		Ok, I might be in the minority here, and that's fine if
I am... but I disagree that we should be dictating the actual API calls
that should be invoked in the JMS API by a conforming implementation.
If you want to talk about the fact that a conforming implementation
should add string property "A" to the request message and that the
values for "A" should be X/Y/Z/whatever, then that's fine, but I don't
think it's correct to say that the conforming implementation MUST call
the javax.jms.Message.setStringProperty("A",<value>) method within the
JMS API layer to set the value.    I'm not taking this position because
my implementation doesn't use the JMS API (in fact it does use it), but
I know of other implementations that might want to "conform" but do not
use the JMS API per se. 
		
		In order to test a conforming implementation, the
robotic "conformance-checking" message consumer (for example) could
receive the JMS message, and (using the JMS API) could retrieve the
various properties from the JMS message and verify that they are set
correctly, etc.     But that does not, in and of itself, require the
conforming implementation to call specific JMS APIs in order to produce
such a request message, does it?        If the "conformance-checking"
message consumer were to use the JMS API to validate the request message
sent by the implementation's message producer component (client
runtime), it would be validating the message from the JMS API standpoint
and would not be validating things at the wire-format level, right? 
		
		Maybe the fact that we're disagreeing on this somewhat
basic issue is an indication that we (as a group) need to precisely
define what we mean by "SOAP/JMS Interoperability" :) 
		
		Phil Adams 
		WebSphere Development - Web Services
		IBM Austin, TX
		email: phil_adams@us.ibm.com
		office: (512) 838-6702  (tie-line 678-6702)
		mobile: (512) 750-6599
		
		
		
		
Amelia A Lewis <alewis@tibco.com> <mailto:alewis@tibco.com>  
Sent by: public-soap-jms-request@w3.org 

05/22/2008 12:30 PM 

To
Phil Adams/Austin/IBM@IBMUS 	
cc
SOAP/JMS (list) <public-soap-jms@w3.org> <mailto:public-soap-jms@w3.org>

Subject
RE: [SOAP-JMS] minutes 2008-05-20	


	
	




		
		On 2008-05-22 12:10:14 -0400 Phil Adams
<phil_adams@us.ibm.com> <mailto:phil_adams@us.ibm.com>  wrote:
		> Well, does the SOAP/JMS spec really dictate which JMS
APIs must be 
		> called by 
		> a conforming runtime?    It specifies, as an example,
the set of 
		> properties 
		> that must be set on the JMS message and the associated
behavior, etc. 
		> but it 
		> doesn't say which APIs must be called by the
conforming 
		> implementation to 
		> achieve that, nor should it in my opinion.
		
		I have to disagree.
		
		While vendors may supply other APIs to manipulate
information provided 
		by their implementation, including the API-level
information, the 
		*only* definition that we have, interoperably, is via
the 
		published/standardized JMS API.
		
		Consequently, manipulation of JMS Headers and Properties
is, defacto, 
		reference to specific JMS API methods.  It can't be
anything *but* 
		that, because that's the only bit that we all agree to
interoperate 
		over.
		
		Complexity kills.  It might be nice to have a
conformance suite that 
		(somehow, via configuration/environment/command line
switches/magic) 
		adapts to the proprietary extensions of each
implementation, but we 
		*cannot specify that*.  I mean, IBM could, for their
stuff, and Sun 
		for theirs, and TIBCO for ours, but the only thing that
we all agree 
		on is JMS API.
		
		Consequently ... our conformance suite ought do
*everything* related 
		to JMS via JMS APIs.
		
		If our specification of SOAP/JMS is not defined via the
JMS API, then 
		it isn't defined, interoperably.
		
		> The reason being that some 
		> implementations might not actually use the official
JMS API to 
		> construct 
		> these messages.      The messages themselves are the
interoperability 
		> point 
		> and not the actual APIs that were called to produce
and consume them, 
		> right?
		
		Absolutely *not*.  Only the API is defined.  "Message"
here presumably 
		means wire format, in some fashion; that's *undefined*
for JMS (each 
		vendor has a specification, certainly, but I don't
believe that there 
		are two vendors who share one).
		
		If it doesn't mean wire format, what does it mean?  If
we're basing 
		our specification on the definition of message, where is
that 
		definition specified?  I contend that it's only
specified via the JMS 
		API specification, which means, effectively, via JMS API
calls.
		
		Amy!
		-- 
		Amelia A. Lewis
		Senior Architect
		TIBCO/Extensibility, Inc.
		alewis@tibco.com
		
		
		
		
Received on Thursday, 22 May 2008 22:18:59 GMT

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