This is also support my short SOA defintion " SOA is about an environment that allows a contract to be made between the provider of the service and a consumer." The contract (interface) should cover all of this aspect in both case of interactions, computer interaction or human interaction the environment should cover the defintion, publishing, finding goverance, invocation,..etc.
Joost <[EMAIL PROTECTED]> wrote: Interesting question. The semantics of the messaging depend on the business transaction. That is; the business negotiation that would take place if computers were not involved. Essentially it's in the form: if you do this i promise to do that So it's a protocol of requests, promises and obligations. So a pizza order service would involve probably some services that represent these promise and obligation steps. But the meaning of these steps are in the real world; not in the IT. It's very similar to buying something on the web; amazon could be lying about the order I made. Or could change the page after I ordered. You'll doctor the protocol to minimize these risks; for instance only use a provider who has an api that let's you pay after receipt. But that's not always feasible. So then you're left with legislation and social reputation mechanisms. To conclude; the semantics of the 'order pizza' service can be expressed as pre- and post conditions: Pre: the client has to have credit, the pizza should be available etc. Post: the clients credit will be charged, the pizza will be delivered within 30 minutes. These semantics will have to be stated in a contract. And there will have to be some recourse if obligations are not fulfilled; legislatory or by a reputation system. Note that these things can not be expressed with REST. REST-semantics are imo. not suitable for business services, only for data oriented backend services. groeten, Joost de Vries --- In [email protected], Jan Algermissen <[EMAIL PROTECTED]> wrote: > > Hi, > > if have SOA-ordered a pizza the other day but yesterday I learned I > sold my house..... > > How do I prove in court that my digitally signed pizza order was > indeed a pizza order and not (as the recipient claims) a house sale? > > Jan >
