Ashley at Metamaxim wrote: > Mark Baker wrote: > > > Application protocols define application semantics. They are not > > "protocols" in the same sense of the word used in systems like CORBA, > > DCOM, RMI, Jini, etc.. IMO, that's the root cause of the > > misunderstanding. If these things had been called "locotorps", this > > confusion wouldn't exist; "protocol independence" would be a good > > idea, since protocols just move bits around. But "locotorp > > independence" would be silly, because everybody knows that locotorps > > define the application semantics, and how can an applications be > > independent of application semantics?! 8-) > > I entirely agree. I have been involved for a while in the theory and > practice of modelling application semantics in terms of their > "locotorps" , and believe that more attention needs to be paid to this > if anything like dynamic discovery/linking to services is to be achieved.
This is the model that Jini and the JERI stack employ to keep the application isolated from the transport protocols. By capitalizing on the power of the Java platform's dynamic class loading, the clients' and server's exchanges that are part of the application protocol are completely independent of the transport layer. This allows the transport to be changed at deployment time, and it can also be determined dynamically so that a clients particular application protocol patterns can drive the transport used to be either more or less secure, more or less overhead, or over alternate networks. For instance, a remote site that might be connected via a T1 normally, can revert to an X.25 route without having a 'router' to do that for it. Naturally, some would say, let the router do that, that's what its designed for. In the case of a failed route, yes. But, what if you need to switch routes because of cost of bandwidth, availability of power, or other more extensive decision trees that are not part of the IP routing layer controls? There is a lot of opportunity when you have dynamic control, at the client of how it interacts with the service. And it's just icing on the cake when the client is never changed, shutdown, or restarted when you decide to deploy new technologies like this. Gregg Wonderly ------------------------ Yahoo! Groups Sponsor --------------------~--> Fair play? Video games influencing politics. Click and talk back! http://us.click.yahoo.com/T8sf5C/tzNLAA/TtwFAA/NhFolB/TM --------------------------------------------------------------------~-> Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/service-orientated-architecture/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
