Re: [soa-rm] Groups - Rough notes taken during the last ebSOA meeting. (ebSOA-Elements.pdf) uploaded

[Ken Laskey <klaskey@mitre.org>]

I have not yet gone through the rest of this thread (and several  
others) but it seems that while the message itself is not part of the  
RM, the ability to create, transport, receive, and possibly  
save/archive the message is part of the RM.  Can we conceive of an SOA  
without messages?  Consider the message exchange patterns (MEPs) that  
are part of WSDL 2.0 for the types of message patterns people imagine.   
Do we think these are accurate?  How does the RM acknowledge these?

Ken


On Mar 30, 2005, at 7:32 PM, Duane Nickull wrote:

> Hi Rebekah:
>
> Some comments inline:
>
> Metz Rebekah wrote:
>
>> All -
>> I have another 25 messages to go before I catch up with all the  
>> traffic
>> on the list, so I apologize if my comments are already outdated.
>>
> I would recommend reading Thomas's elegant summary - it may save you  
> some time ;-)
>
>
>> Respecting the service description, contract, and data model from
>> Duane's message - does you think that "all aspects of the service"
>> encompasses the service interface and the policy?  I like the use of  
>> the
>> term service contract, but have seen several interpretations of the  
>> term
>> ranging from semantics ("what is meant") to syntax (vis a vis the  
>> WSDL)
>> and also that the WSDL is the data model is the contract.  I would  
>> argue
>> that the contract is the same as the data model.  However, I'd have to
>> think a bit more to provide a convincing argument rather than simply
>> positing an idea.
>>
> The data model is the abstract concept of what data you will pass in  
> and out of a service.  An open ended question is "does the data model  
> include the notion of semantics?".  I would like to hear comments back  
> on this matter.
>
>> Continuing into the message, I would disagree with the following:
>>
>>> If I build something and that is "Service Oriented" architecturally,  
>>> does it have to have a "message"?  No - the service itself has a  
>>> mechanism that allows a service consumer to bind to it to invoke the  
>>> service but it doesn't actually have to be invoked for it to be  
>>> "service oriented architecture".
>>
>> I would argue that conceptually, a message exists.  <SNIP>
>>
>
> Try to think abstract.  If you think concrete - then the answer is  
> yes, however the reference model is not concrete.  No other reference  
> models use messages by convention either.  If you find one that is  
> well scrutinized and accepted by peers, please let me know.
>
>> The mechanism by
>> which the consumer binds to the service and invokes it constitutes the
>> message.
> Conceptually - yes.  The "service" element of the SOA RM draft on the  
> position paper includes the concept of a binding.  A physical message  
> does not have to be sent.  When using the RM to write a concrete SO  
> infrastructure architecture, one would recognize that a message  
> protocol would likely be needed to be specified, along with several  
> other items like security, potentially some sort of state management  
> (like BPM), etc etc.
>
> I hope this helps a bit.
>
> Duane
>
> --  
> ***********
> Senior Standards Strategist - Adobe Systems, Inc. -  
> http://www.adobe.com
> Vice Chair - UN/CEFACT Bureau Plenary - http://www.unece.org/cefact/
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>
>
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Ken Laskey
MITRE Corporation, M/S H305     phone:  703-883-7934
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