fat clients in dolphin

For using dolphin for developing fat clients for server apps, what options
are there available currently to connect to an esisting server side?
Interesting are mainly CORBA and DCOM, although it is feasible to install a
server component written in dolphin as well. In the latter case, we need
only some means of high level remote communication between two dolphin
processes. It should be high level, though (passing objects by ref, by value
etc.).

Ciao

...Jochen

Jochen,

> For using dolphin for developing fat clients for server apps, what options
> are there available currently to connect to an esisting server side?
> Interesting are mainly CORBA and DCOM, although it is feasible to install
a
> server component written in dolphin as well. In the latter case, we need
> only some means of high level remote communication between two dolphin
> processes. It should be high level, though (passing objects by ref, by
value
> etc.).

I strongly urge you to stay clear of DCOM.  It seems great until you hit a
real network, and then its error handling will cause you ongoing grief.  I
worked with at least three CORBA ORBs, and all of them shamed DCOM -
even/especially the free one.

The "cool" answer right now is web services and XML marshaling.  They might
be the right answer, but I am quite skeptical.  XML is, well, not compact :)
Not to impugn SIXX, but in one example I checked recently, it produced a
roughly ten times longer output than Squeak's SmartReferenceStream.  In an
unrelated test, the latter did not compare well to Dolphin's binary filer.
However, my work with SIXX and SmartReferenceStream has been limited to
persisting fairly complicated objects.  There is nothing distributed about
the problem (it's for that MIDI thing that I've mentioned elsewhere), but
the objects involved are just the kind that one would want to reference vs.
send by value.  That's a long way of saying that the inefficiencies of XML
might not bother you, and there are (based only on casual review) some nice
efforts at providing web services in both Dolphin and Squeak.

Still, my long-term bet is on CORBA/IIOP, avoiding all services (except the
naming service).  The bad news is that we don't have a CORBA binding for
Dolphin.  Forgetting the complexities of an IDL parser and stubber, one
might get a big boost by using ILU (or some other project's) sources to
cobble together header files that could in turn yield a type library and
(courtesy of the type library analyzer), structure classes.  Then what?
That makes two of us :)

Have a good one,

Bill

--
Wilhelm K. Schwab, Ph.D.
[hidden email]

"Bill Schwab" <[hidden email]> wrote in message
news:aufqei$hna$[hidden email]...
> Still, my long-term bet is on CORBA/IIOP, avoiding all services (except
the
> naming service).  The bad news is that we don't have a CORBA binding for
> Dolphin.  Forgetting the complexities of an IDL parser and stubber, one
> might get a big boost by using ILU (or some other project's) sources to
> cobble together header files that could in turn yield a type library and
> (courtesy of the type library analyzer), structure classes.  Then what?
> That makes two of us :)

Bill,

we run our trading system on top of CORBA orb (with private ESIOP), but
unfortunatley chances of ZSE releasing it are close to zero. Maybe creating
one independently would not be a bad idea if there is enough interest, but
finding time to do it would be a non trivial problem :)

Here is also one thing that could make it at least a bit simpler at the
begining: I would, at least for the start use external idl and interface
repository. There are quite a few usable ones, and some of them are free.
This will simplify implementation since it would not be necessary to do idl
parsing, etc.. However, I would need to see if idl pragmas necessary for
smalltalk can be easily implemented in this scenario.

rush
--
http://www.templatetamer.org/

"Bill Schwab" <[hidden email]> wrote in
news:aufqei$hna$[hidden email]:

> Not to impugn SIXX, but in one example I checked recently,
> it produced a roughly ten times longer output than Squeak's
> SmartReferenceStream.

That's at least partly because SIXX seems to encode very inefficiently, rather than just
XML's ineffiency. Form a quick look, SIXX seems  the equivalent of an ASCII encoding that
uses only the letter 'A' ...

P.

> That makes two of us :)

Hum, does not sound too promising ;-). The absence of a CORBA interface or
at least a built in proprietary (but somewhat efficient) remote interfacing
is really a pitty, as all the other features of Dolphin make it excellent
for fat client development.
I will play with the dolphinharbour stuff for now, as I have currently not
enough time to start a project on this.

Thanks for all the infos!

Ciao

...Jochen

Hi Jochen,

Spray does not provide any ORB facilities; it is service based, effectively
a client can only send a request to a single service object.

Masashi Umezawa's SoapOpera for Squeak contains an ORB which could be ported
to Spray to provide an ORB via SOAP.

I recently came across some goodies from the Smalltalking group at:

    http://www.smalltalking.net/Goodies/Dolphin/

The Remote Smalltalk package sounds like it could do what you need.

Thanks,
Steve

--
Steve Waring
Email: [hidden email]
About: http://www.dolphinharbor.org/dh/harbor/steve.html
Journal: http://www.stevewaring.net/blog/home/index.html

Hi Steve...

> The Remote Smalltalk package sounds like it could do what you need.

Wow, cool! Thanks for the link :-)

Ciao

...Jochen