Steven, 2008/4/16, Steven Newhouse <Steven.Newhouse@microsoft.com>:
The addition of provenance is one useful addition provided by this concept... especially if the document is being passed around from broker to broker and BES endpoint. For this provenance to be useful it needs to be trusted... how are you going to record who (really) changed thing... signing or something else? And how will you stop the document and change history growing ecessively...?
from my point of view, I don't see the document to be "passed around". Instead, I'd like an endpoint where I can access and modify the document throughout the entire process plus the ability to "finalize" a certain version after the activity's lifecycle has ended. This introduces a slightly different notion of trust (the endpoint has to AAA the manipulator of the document). What's more, a model for the handover from one broker to another is necessary, since both have to agree on the delegation *and then* write provenance information both are happy with. Regarding the size, I agree that an activity record could grow pretty large. But I don't see the problem here -- that's up to the implementors of the activity backend. As I said before, I wouldn't pass around the whole document, but a reference to it solely. Anyway, for the document schema itself, I don't think these aspects are an issue (except for the finalization, maybe). When it comes to consuming/providing services, however, we need to discuss that again. Regards, Alexander -- Dipl.-Inform. Alexander Papaspyrou http://ds.e-technik.uni-dortmund.de/~alexp Robotics Research Institute phone : +49(231)755-5058 Information Technology Section fax : +49(231)755-3251 Dortmund University of Technology, Germany