Re: GNOME CVS: gnome-core mmclouglin

[Owen Taylor <otaylor redhat com>]

Sander Vesik <Sander Vesik Sun COM> writes:

> On Sun, 2 Dec 2001, ERDI Gergo wrote:
> 
> > On Sun, 2 Dec 2001, Alan Cox wrote:
> > 
> > > > So what's inherently more lightweight in SOAP in comparison to CORBA?
> > > 
> > > Thats still comparing whales to one another. 
> > 
> > I don't see what huge amounts of superflous information CORBA the protocol
> > passes around that qualifies it as a 'whale'. Sure it would rule to be
> > able to trasmit data (in this case, method invocation requests) without
> > using any actual bandwidth, but there's this evil 'Physics' thing that
> > keeps us from doing that.
> > 
> 
> There are other RPC protocols that are more lightweight than CORBA. I'm
> not sure how high on thelist of prorities lightweightness was when CORBA
> was designed but it could not have been tat high 8-)

There seems to be a _lot_ of confusion going around here, perhaps
in the terminology of "lightweight"

 * The on-the-wire marshalling format of CORBA (IIOP) is quite
   efficient in bandwidth and not at all slow to marshal. If you can
   write SOAP marshalling code that reaches 1/100th the speed
   of a decent IIOP implementation, I'd be impressed.

 * There is some complexity inherent in the object key lookups 
   and especially in the POA, but there is no reason that 
   this should take more the a few microseconds.

If you are interested in doing round-trip invocations on persistant
remote objects, I think CORBA is going to be about as good as you can
get.

I think what Havoc meant by lightweight was not in the efficiency of
the core operations, but in the overrall structure of the
system. CORBA is meant to be a very comprehensive and thorough system
for doing round-trip invocations on remote objects.  If you want to do
asynchronous messages, local invocation, etc, then you have to build
it on top of the complete solution as extras.

Furthermore, all the additional features that have been standardized
on top of CORBA (messaging service, real time extensions, security,
etc) are extraordinarily thorough, complex and BIG.

So, if you want the core part of CORBA, then it is not at all
inefficient, but if you want something a little different - (and you
do, because it's latency, not bandwidth, etc.) - then you have core
CORBA + big extension and it will be inefficient and you'll never
figure it out anyways.

Regards,
                                        Owen

[ SOAP, on the other hand, isn't exactly simple either ... ]