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

[Manoj Dhooria <manojd@geometricsoftware.com>]

SOAP-based CORBA/COM bridge over WAN (or were you talking only about LAN -
in which case, my apologies for this message) - very interesting, but did
you wonder about performance & coupling issues for an application built over
it:

a) Programmers want to access objects at the lowest granularity that makes
sense to application. If I have a circle object, I want access granularity
to be so low to let me query the radius or center individually. I don't know
how the caching techniques of generic systems like COM are going to help
you. You nearly always will want domain specific caching - means you want to
control the granularity of the data moving over the IP network, as well as
triggers to refresh/fill-in the specific cache elements.

b) Client "forgets" to release an object interface at server! As an
application programmer, I want complete control over the client/server
coupling. I am not aware of a way to do it in COM. And common sense tells me
I am unlikely to find it in CORBA & EJB too - or am I wrong?

May be SOAP helps you make these object models interoperate over LAN. But
forget about any substantial services that use them over WAN.

Manoj Dhooria
Geometric Software, Bombay

-----Original Message-----
From: Joshua Allen [mailto:joshuaa@microsoft.com]
Sent: Sunday, August 19, 2001 10:05 AM
To: Brendan Macmillan; xml-dev
Subject: RE: CORBA vs. XML (was: Re: XML.COM: How I Learned to Love
daBomb)


>Has anyone published a point-by-point comparison between CORBA and
>SOAP/XML-RPC?

You could probably consider SOAP and CORBA as complimentary.  SOAP to
IIOP might be a better comparison.  The three "big" object server models
out there have been CORBA, EJB, and COM+ -- these three use IIOP, RMI,
and DCOM respectively as the primary method to pass information to and
from objects.  Now that SOAP is on the scene; CORBA, EJB and COM+ don't
go away, they just have another way to pass information to and from
objects.  In fact, before SOAP, there were many ways to get these three
different worlds to interoperate -- the difference with SOAP is that the
interop layer is based on XML, supposedly easier to implement than
something like an RMI/DCOM bridge, and so on.  For example, if I have
some objects written in CORBA that provide some service, I no longer
have to convince all of my customers to install an IIOP communication
layer.  With SOAP, the layer that calls my CORBA object could be as
simple as a UNIX bash script that pipes some text through netcat.  So I
think of SOAP as being a universal IIOP/RMI/DCOM substitute that mere
mortals can type by hand.

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