- From: Ricky Ho <riho@cisco.com>
- Date: Tue, 25 Mar 2003 09:57:41 -0800
- To: "Jean-Jacques Dubray" <jjd@eigner.com>
- Cc: <public-ws-chor@w3.org>
JJ, comments inline >A binary collaboration can easily be used as part of an agreement, as >well as to configure run-time engine that "monitor" the choreography >(firewall concept). I think the "monitor" doesn't restricted to binary collaboration. It applies to multi-party as well. >In the case of a multi-party, we might want to ask whether the goal is >simply to represent what is going to happen such that each party can >infer what they need to do. Hence decompose the multi-party into >bilateral behavior (which will itself be decomposed in unilateral >behavior). Decomposing multi-party into bi-party may lost some information about dependencies (see the doctor/patient use case) and is not always possible. I'm not sure I understand "unilateral behavior", sounds like it is a private implementation. >Is there a need to establish multi-party agreements based on a >multi-party choreography definition? I guess a multi-party choreography is only useful when all defined roles agree to conform to. So this is a multi-party agreement. >At the run-time engine level, things gets far more complicated because >unless there is a party that touches all the "bilateral choreographies", >it is impossible without special run-time to "monitor" the multi-party >choreography. So the question arise, is the goal of a multi-party >choreography specification to allow configuration of run-time engines? I think it is possible to monitoring all traffic pattern of a single party conforms to a multi-party choreography. (you still need to have multi-party definition to do that). If every party agrees to put a monitor, then you certainly can get the whole picture. But even monitor one party can provide high value. >In think in the light of this, we should not conclude that binary is a >special case of multi-party. They may well have both distinct features >(control flow?) and applications. Does multi-party covers the case when N = 2 ? Is so, then bi-party is a special case of multi-party. But I agree that bi-party may have some extra properties (such as a simpler role binding model) that we should take a serious look at. >I am also wondering if the group wants to keep as a requirement that >says that in the choreography specification there is no distinction >between the choreography involving "internal" services as opposed to >external services. A separate layer of the specification should allow >for annotating that this particular message exchange is external and may >have more qualifiers. However, at the pure choreography specification >level, the choreographies should not be distinguished. If choreography is only meaningful to specify a contract between multiple "domain of control", then it should only focus in the message exchange across the boundary, which means external services ? Right ? Rgds, Ricky
Received on Tuesday, 25 March 2003 12:58:22 UTC