Toby Considine wrote:
> SOA at some level is nothing more than OO writ big (nothing new there!) (01)
Duane Nickull wrote: (02)
> I would consider this not quite true. Service oriented architecture is a
> paradigm for architecture (software or otherwise), that matches needs and
> capabilities across multiple domains of ownership. This makes it
> substantially different from OO which is typically under one environment and
> one domain of ownership. (03)
I would never have said that "OO is typically under ... one domain of
ownership". Any set of software that is created under a single
program-of-work is under one domain of ownership, regardless of its
architectural paradigm. (04)
But the whole idea of "interface presentation", "instantiation", and
"encapsulation" (which are the heart of object-oriented technology) is
that one domain of ownership can use things that were created in, and
still owned by, another. Lots of programmers write Java programs using
open-source libraries that fit their needs. And vendors write software
tools to run in the Windows environment using off-the-shelf DLLs with
documented (OO) interfaces. And I assumed that these ideas are what
Toby meant when he said SOA is OO writ big. (05)
What forced the "single domain" behavior on CORBA and Java/RMI
environments was the "broker"/"app server" concept. But there is
nothing OO about the broker/app-server concept; it was just an easy
implementation architecture for earlier distributed systems. I can
agree that SOA is a departure from the server/broker *architecture*, but
that part of the CORBA/Java architecture is not an OO property. (06)
Once you generalize the "directory service" concept and provide some
kind of "dynamic binding" capability, CORBA (3.0) and Java (J2EE) also
supported interdomain interactions of autonomous agents. (07)
I should say, BTW, that this problem of "portmanteau concepts" is a pet
peeve of mine. People regularly seem to confuse guiding principles with
implementation choices in identifying the facets of a thing like SOA.
This is also why someone else earlier said that SOA has nothing to do
with "webservices" a la WSDL/SOAP -- the same principles can be applied
in a J2EE implementation environment. (08)
-Ed (09)
--
Edward J. Barkmeyer Email: edbark@xxxxxxxx
National Institute of Standards & Technology
Manufacturing Systems Integration Division
100 Bureau Drive, Stop 8263 Tel: +1 301-975-3528
Gaithersburg, MD 20899-8263 FAX: +1 301-975-4694 (010)
"The opinions expressed above do not reflect consensus of NIST,
and have not been reviewed by any Government authority." (011)
_________________________________________________________________
Message Archives: http://ontolog.cim3.net/forum/ontolog-forum/
Subscribe/Config: http://ontolog.cim3.net/mailman/listinfo/ontolog-forum/
Unsubscribe: mailto:ontolog-forum-leave@xxxxxxxxxxxxxxxx
Shared Files: http://ontolog.cim3.net/file/
Community Wiki: http://ontolog.cim3.net/wiki/
To Post: mailto:ontolog-forum@xxxxxxxxxxxxxxxx (012)
|