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

["Gregory A. Kohring" <kohring@ccrl-nece.de>]

Duane,

> 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".  Does a car have to be driven on a road before 
> it is a car?  The answer is likewise "no". 


I think you have your analogy a little bit confused here. It is not a
question of whether a car has to be driven before it is called a car,
but whether a car without wheels is called a car. It would seem to me
that a service without "message" is not a service.

Go back to the coffee shop example. The service a coffee shop offers
has a well defined  message exchange protocol which works the same the
world over. Basically it involves the consumer placing an order, the
server  confirming the order, then the server requesting payment.
This is a very generic message exchange protocol which has also been
taken up by many online shops.

This is not the only possible protocol, you could demand a down
payment before the consumer orders the service, in which case you
probably want to rearrange your coffee shop so that people have to pay
before entering. (Or you make people put a down payment before
browsing your online store.) Hence, the choice of protocol has an
impact on how the service is designed.

In my opinion, messages and by extension the protocol frameworks
within which they are embedded are fundamental to SOAs and should
be part of any reference model.


Cheers,

Greg Kohring


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G.A. Kohring
C&C Research Laboratories, NEC Europe Ltd.
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