Re: [soa-rm] Negotiation? (was: [soa-rm] Good Recent SOA Piece:"Managing an XML Data Model In Your SOA - Best Practices")

[Duane Nickull <dnickull@adobe.com>]

I suggest we consider the higher level of abstraction for negotiation.  
The basic pattern of interaction for negotiation is inclusive of 
decision.  There are a set of policies stated (an offer for the other 
party to accept) and some entity accepts or rejects them.  The concept 
of negotiation is a facade of something dynamic happening but really it 
is just that the roles are reversed between the offerer and the 
acceptor.  In each case, there are a set of things offered and they 
either meet nor do not meet the minimal acceptable requirements of the 
other entity.

A specific example - a service states everything it is capable of in 
terms of policies, parameters, etc.  You could build the facade of 
negotiation by making a special interface that accepted the "suggestion" 
of a set of parameters for service innovation that are outside of the 
outer, publicly stated policies, however the resolution and determinism 
would be the same mechanism.  Once the service accepted the 
"suggestion", it would still check internally with a set of policies to 
see if it is within the accepted limits.  Same pattern - Decision.

Most architects would probably be reluctant to implement things this way 
based purely on making it appear as if negotiation was actually taking 
place.  There may be some specific examples of how it may be desirable 
to build this facade but I am not sure it is important for the RM.

Duane

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Senior Standards Strategist - Adobe Systems, Inc. - http://www.adobe.com
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