Re: CORBA vs. XML (was: Re: XML.COM: How I Learned to Love daBomb)

[Al Snell <alaric@alaric-snell.com>]

On Sat, 18 Aug 2001, Brendan Macmillan wrote:

> Obviously, using XML makes it human readable; but I think the biggest
> difference is that the latter two are merely method invocation (and that's
> *easy*); while CORBA implements "remote objects", and the horror of issues like
> maintaining state, remote memory management etc and so on.
>
> Have I got that right?

No, Corba does just do method invocation. The ORB itself can do other
complex stuff like implementing persistent objects and so on, but then
it's more of an object database with an ORB interface :-)

> In principle, web services are no different from any other TCP/IP service (like
> ping, telnet, ftp, etc etc etc) except that they use XML, and have a more
> general way of specifying the method to be invoked... whereas CORBA is (was?)
> *much* more ambitious.

IIOP, the on-the-wire protocol, is just that. CORBA also defines a lot of
standard interfaces and stuff but you don't need to know about them unless
you're going to use them.

There are CORBA naming services and CORBA Object Transaction Services and
stuff, but unless you use them, don't install them. It's just like UDDI
and RDDL and RDF and stuff.

> It's a bit like how Java simplified the pointers of C, and the OO of
> C++, to make something that was a *lot* simpler and less error prone,
> and (by the 80-20 rule) sufficiently powerful 80% of the time...
>
> But I really would like to see a point-by-point comparison, if anyone
> has done one, or knows of one (or would like to do one now).  ;-)

/me looks at his schedule and wonders about sleep and stuff

*ugh*

Just read a book on it, it's easy :-)

ISBN 0-471-12148-7 describes the issues involved in networking stuff,
and describes CORBA in 110 pages, then spends 39 pages describing
interfacing to it from C, C++, and Smalltalk (that'd be Java in a more
recent book I expect). The rest of the book describes the CORBAServices,
which are standardised interfaces to stuff like security, transactions,
and so on.

>
> Cheers,
> Brendan
>

ABS

-- 
                               Alaric B. Snell
 http://www.alaric-snell.com/  http://RFC.net/  http://www.warhead.org.uk/
   Any sufficiently advanced technology can be emulated in software