davideng2004@y... (David Eng) wrote in message news:<6b74193f.0406020749.39374b7c@p...>...
> Gerald Brose <gerald.brose@x...> wrote in message news:<2i5gvaFhvjq7U1@u...>...
>  
> > The point for using Web Services is not that you cannot model
> > services using CORBA, or that Web Services would be capable of doing
> > everything better than CORBA can. Both statements are just wrong.
> > This discussion is popping up again and again, as if Web Services
> > were trying to be CORBA's successor for RPCs...
> > 
> > The point is that Web Services are better suited than CORBA for cross-
> > domain B2B applications because of a few inherent properties of XML
> > messaging, frequently summarized as loose coupling. (Extensibility,
> > finer-grained contracts, marshalling with partial type information,
> > etc.).
> > 
> > CORBA delivers better performance, and the type-safe IDL inter-
> > faces are well-suited for closely integrated intra-domain
> > applications.
> > 
> > For loosely coupled application-to-application communication
> > that cannot rely on a homogeneous middleware layer such as
> > CORBA and may need to be rearranged to integrate more systems
> > every other month, you will be better off with Web Services.
> > XML messages are especially suited for document-style inter-
> > actions, and the performance hit is tolerable in many of
> > these applications. People also tend to believe that the
> > firewall-friendliness of HTTP is a good thing...
> > 
> Totally agree.  The comparison between IDL and WSDL or Web service and
> CORBA is meaningless because they address different abstraction in
> which IDL addresses object model and WSDL addresses document model. 
> Web service shall be developed as an MOM-based middleware which
> requires a document model instead of RPC-based or RMI-based middleware
> which requires an object model.   In this way, Web service and CORBA
> are complementing each other instead of competing each other. 
> However, the focus and current development on RPC-based Web service is
> very wrong, IMO.  The mapping between IDL and WSDL makes no sense.  I
> don't know when market will realize this and shift the focus to
> MOM-based Web service to replace Tibco, MQ, JMS, EAI, and bunch of
> proprietary message middleware, so we can have a platform, language,
> and vendor independent MOM-based Web service and RPC-based CORBA. 
> What a wonderful world!

CORBA has always had an MOM-like capability, i.e. Event Service, and
more recently asynchronous messaging capability (fire-and-forget) via
the Messaging Service specification, and is very much platform,
language, and vendor independent.

The fact that the proprietary MOM vendors never support the CORBA
Notification/Event Service is unfortunate, and reflects the power they
possessed to lock in their customers. The introducion of JMS was a
step in the right direction.

Associating CORBA with RPC style communication is misleading. The
ability to loosely couple CORBA objects has always been available. The
type of payload, e.g. document vs. message, is an application design
decision, not a middleware requirement.

I agree that the initial focus on Web Services has been in the RPC
area, and I'm not sure when the transition to document-centric
processing will occur.