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Re: WSA diffs from REST

From: Geoff Arnold <Geoff.Arnold@Sun.COM>
Date: Thu, 19 Sep 2002 17:40:13 -0400
To: Mark Baker <distobj@acm.org>
Cc: David Orchard <dorchard@bea.com>, www-ws-arch@w3.org
Message-id: <61179139-CC18-11D6-A8D3-000393991304@sun.com>


On Thursday, September 19, 2002, at 04:46  PM, Mark Baker wrote:
> Software architecture is the architecture *of* implementation;
>
>   "A software architecture is an abstraction of the run-time elements  
> of
>    a software system during some phase of its operation.[...]"
> --  
> http://www.ics.uci.edu/~fielding/pubs/dissertation/ 
> software_arch.htm#sec_1_1

Your interpretation of Fielding's (somewhat ambiguous) definition seems  
to
suggest that an architecture is coupled to an implementation. That is  
certainly
not a particular common position (though I'm sure we have all  
encountered
post-hoc architectures). A more common usage runs something like this:

    A software architecture describes the structural properties of  
software,
    typically the components and their interrelationships, and guidelines
    about their use.

This is taken from  
http://www.opengroup.org/architecture/adml/background.htm
which introduces the Open Group's Architecture Description Markup  
Language,
part of TOGAF (which evolved from the DOD TAFIM (Technical Architecture
Framework for Information Management). The point is that the components  
and
their structural relationships are not necessarily coupled to any  
particular
implementation technology. It makes sense to ask whether a particular
system implementation *conforms* to such an architecture. You seem to
be saying that that would be a tautology....

(I have to say that I don't like Fielding's definition at all, the more
I look at it. Read literally, it means that an architecture can change
from one "phase of operation" to the next. That's just plain weird, and
seems completely incompatible with common usage.)

Geoff
Received on Thursday, 19 September 2002 17:40:14 GMT

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