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

From: Peter Easton <peaston@progress.com>
Date: Thu, 22 May 2008 17:26:00 -0400
Message-ID: <3712271BEF30D74CBEA9E827CD9ABDBD017E07A7@MAIL03.bedford.progress.com>
To: "Eric Johnson" <eric@tibco.com>, "Amelia A Lewis" <alewis@tibco.com>, <public-soap-jms@w3.org>
Eric can you explain this. Are you saying the JMS Server is removing JMS
properties before client delivery at F ?
 
"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 21:27:15 GMT

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