Re: [soa-rm] Re: shared state

[Danny Thornton <danny_thornton2@yahoo.com>]

Gary's example draws a good analogy between
established human services within organizations and
the potential for the end result of specialized
interoperable SOA services.    

From a human perspective, if there are
misunderstandings in the "inherently private" state of
a human service, people can adapt and make corrections
for the misunderstadings if needed. For a computing
environment, I would quantify "inherently private". In
the SOA RM, state is an abstract set of concepts as
stated in Interactions, Real World Effects, and the
Execution Context.  The quantification of achieving
state is defined by Visiblity, Service Descriptions,
Contracts and Policy, and Interaction.

Gary's discussion follows Duane's statement of a
service/entity maintaining its state.  This also
follows my view of state when discussing a computing
system.  I like Frank's points about shared state and
views and I think Frank's statements are accurate and
appropriate at the level of a Reference Model.

Danny

--- Ken Laskey <klaskey@mitre.org> wrote:

> Gary,
> 
> Are you signed up as a member of the TC.  If you are
> only an  
> Observer, then I'm not sure it allows you to post.
> 
> Ken
> 
> 
> On Apr 22, 2006, at 8:24 PM, GPOINDEXTER@wi.rr.com
> wrote:
> 
> > For some reason I am unable to communicate with
> the TC. My messages
> > are rejected. Please consider the following - I
> give up.
> >
> > gary
> >
> >
> > Here is the context for my attempt at a shared
> state definition:
> >
> > In a justice incident we have a suspect (entity).
> The suspect has
> > various states such as wanted, arrested, booked,
> charged,
> > incarcerated, released, etc. Many services are
> involved from many
> > justice domains (police, courts, jail,
> corrections, etc.). They
> > provide and consume services related to the
> incident, subject,
> > location, charges, etc. but not necessarily with
> all other
> > participants and generally not all at the same
> time. So we have many
> > entities in common, the shared state of which is
> affected by many
> > services consumed and provided by common
> participants.
> >
> > If this doesn't fit the context of the discussion,
> then I'll go back
> > to listening mode.
> >
> > If nothing else, try knowledge of vs. view.
> >
> > gary
> >
> >
> > Try this:
> >
> > When the state of an entity is affected by
> multiple services or
> > multiple consumers of a single service, the state
> of the entity is
> > referred to as a "shared state." At any given
> point in time all
> > participants may or may not be aware of a change
> in shared state of an
> > entity, but the state must be discoverable;
> particularly when the
> > participants are not in the same ownership domain.
> >
> > Sharing the state of an entity does not imply a
> common repository for
> > that state or entity. Instead, each participant
> has knowledge of the
> > state on its own as well as the world's knowledge
> of the state,
> > including those aspects that are shared. A
> participant's knowledge of
> > the world's state is inherently private to the
> participant. I.e.,
> > there may be shared state but each participant has
> its own private
> > knowledge of that state.
> >
> > There is a strong relationship between shared
> state and the
> > interactions that lead up to that state. Typically
> in the form of
> > messages and other information that has been
> exchanged, this evidence
> > is information that supports the set of facts and
> commitments that are
> > shared.
> >
> > It is not required that the interactions be
> recorded; although without
> > such recording it may become difficult to audit
> the shared state and
> > commitments at a subsequent time.
> >
> > gary poindexter
> > <xmlLegal>
> > Mobile: 414-467-8222
> > Fax    : 770-216-1633
> > Email: gary.poindexter@xmllegal.org
> >        gpoindexter@wi.rr.com
> >
> 
> ---
> Ken Laskey
> MITRE Corporation, M/S H305     phone:  703-983-7934
> 7515 Colshire Drive                        fax:     
>   703-983-1379
> McLean VA 22102-7508
> 
> 
> 
> 


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