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Re: Requirements: Decision Points Requirement Proposals

From: Jon Dart <jdart@tibco.com>
Date: Wed, 04 Jun 2003 17:05:34 -0700
Message-ID: <3EDE894E.2000709@tibco.com>
To: "Yaron Y. Goland" <ygoland@bea.com>
CC: WS Chor Public <public-ws-chor@w3.org>

It would be helpful to understand the motivation behind these 
requirements, either in the form of a use case or other rationale (I 
believe for some of the proposed text this exists and has been 
previously discussed, but perhaps not for all of it).

--Jon

Yaron Y. Goland wrote:
> I propose the following requirements be added to the requirements document:
> 
> The WS-Chor choreography description format MUST provide mechanisms to
> enable a choreography to specify that a process in a particular role MUST
> send zero, one or more messages from a statically defined set of messages in
> parallel, serial or any combination of the two.
> 
> The WS-Chor choreography description format MUST be able to describe
> decision points where a process in a particular role MAY send zero, one or
> more messages from a statically defined set of messages in parallel, serial
> or any combination of the two.
> 
> The WS-Chor choreography description format MUST be able to describe who is
> to receive a message by referencing their role.
> 
> The WS-Chor choreography description format MUST make it possible to specify
> a role's binding to an actual web service instance either statically, when a
> web service using that choreography is deployed, or dynamically at run time.
> 
> The WS-Chor choreography description format MUST provide mechanisms to allow
> messages to be sent to a particular member of a set of web services in the
> same role.
> [Ed Note: What I'm very inelegantly trying to capture is the idea that if
> you are running an auction service and you just found out that one of the
> bidders isn't qualified to bid you need a way to say things like "I'm now
> going to send out an unsolicited 'get lost you dead beat' message to one web
> service that is in the role of bidder." This could then trigger a whole set
> of messages back and forth between the auction service and the dead beat
> bidder, the choreography needs some way to capture the fact that you are
> still talking to the same member of the role group.]
> 
> The WS-Chor choreography description format MUST NOT require that the logic
> used by a sender in a decision point to decide how to act be exposed in the
> choreography.
> 
> The WS-Chor choreography description format MUST enable the annotation of
> all actions with human readable descriptions.
> 
> The WS-Chor choreography description format MUST provide an abstract
> mechanism where by the logic used to make a decision at a decision point can
> be expressed through reference to a WSBPEL abstract or executable process or
> similar machine readable logic.
> 
> The WS-Chor choreography description format base specification MUST NOT
> specify bindings for the abstract mechanism used to reference machine
> readable logic, rather extension specifications on top of the base
> specification MUST be used.
> 
> I would appreciate it if objections to these requirements were stated in the
> form of alternate proposals. It's easy to say why something is wrong, it's a
> lot harder to spend the time to specify what is right.
> 
> 		Yaron
> 
> 
> 
Received on Wednesday, 4 June 2003 20:06:29 GMT

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