RE: [soa-rm] David Linthicum Says: "ESB versus Fabric.Stop It!"

["Metz Rebekah" <metz_rebekah@bah.com>]

> Can I ask you what would make a single service care that the consumer
is
> invoking it as part of an orchestration?  Why should the service care.
> It's function is simply to facilitate the invocation request.  If
> someone created a dependency on the service to know about the state of
> other service invocation requests, that would be very bad architecture
> IMO and also violate the principles of autonomicity (not really an
> English word but you get the idea).

Ah!  So here lies an important distinction that gets back to the
house/community analogy - and what makes SOA a SOA?  Is SOA == the house
or is SOA == community?  A single service probably wouldn't care whether
or not it is being invoked as part of an orchestration, much like a
house doesn't care if it is in a planned development or urban
development or a cornfield or an island.  But, a SOA may very well care
about it, much like a community cares about things like the positioning
of individual houses and green space (which don't directly related to an
individual house).

 
> I will propose that we accept this axiom:
> 
> "Services should not have to have explicit knowledge of the states of
> other services called by a consumer that invokes them"

So this goes back to the service as an operational concept, and I think
leads me to think that we are working toward a definition at the
"community" level and not at the "house" level.

Rebekah