On Aug 24, Toshiyuki Nakata modulated:
Karl: thank you very much for the excellent summary. (which I must admit I would need a week to really digest.).
One thing that I (and I think you also pointed out ) was that that in the case of AR not agreeing, there were not enough hints for the AI to initiate another request..
Any comments on this?
Well, my practical view, keeping in mind bounded-rationality systems, is that if the template was insufficient to guide you to an acceptable agreement offer, then a "hint" would not fair any better. Either the advertiser announces its policies/restrictions in detail sufficient to create an agreement, or it does not. Why would it reveal more information on the next iteration? If you're trying to address intelligent parties who do bluffing and bartering, then your problem is out of scope for WS-Agreement... Another intractable problem is that the resource manager making the decision may not even be able to formulate a specific reason for "why it didn't match", e.g. in a scheduler that is matching many properties at once against a dynamic load of competing requests, it is not necessarily easy to determine what would need to change to make a request get handled above other requests. Furthermore, it would have race conditions since the dynamic load may be different by the time the next offer arrives. So I think in practice, an automated WS-Agreement initiator is going to operate with some narrowly-defined commodity offers and try fallback, retry, and fail-over among responders. If this fails, offline analysis and problem determination will be required to understand what went wrong, and how to improve templates and offering systems to avoid these doomed offers. karl -- Karl Czajkowski Software Architect Univa Corporation 1001 Warrenville Road, Suite 550 Lisle, IL 60532 karlcz@univa.com www.univa.com ________________________________________________________________ www.univa.com. The Leaders of Open Source Cluster and Grid Software