Looking for an approach...

Looking for an approach...

Post by Heiko Tapp » Tue, 17 Aug 2004 19:12:02


I have a two-tier application written in D6, working on a Firebird or Oracle
backend.
Now I would like to (have to?) add a middle tier for only some time
consuming functions because
the number of concurrent users will increase from about 100 to 800 or so.
The time consuming functions I would like to "extract" from the client could
be able to share
already calculated data via some cache and so reduce response time.

What are the possible approaches I could use? Which might be best?
CORBA, SOAP, DCOM, COM+, ...
I like the idea of using CORBA but AFAIK there are several issues concerning
Delphi+CORBA.

BTW, I still want my app to be runnable in two-tier mode, because most of
the customers don't need
a speed-up. So I was thinking about a cond define, to be able to compile two
different kinds of
app types from the same sources.

Any suggestions are very welcome
--Heiko
 
 
 

Looking for an approach...

Post by Dan Palle » Wed, 18 Aug 2004 01:26:12


Oracle
could
concerning
two

I'm in the same boat. I was going to go the DCOM/Datasnap route but the
release of D8 with it's limited Datasnap capability put my plans on hold.
Ideally, I'd like to write the server pieces in D8/.NET and have my clients
still be in Win32 for now. Hopefully, D9 will give us additional options
here.

Whatever approach you take, you should be able to run the middle-tier piece
locally for those clients that don't want/need a middle-tier server. I
would think this approach would be much simpler than compiling two versions
of the application.

Dan

 
 
 

Looking for an approach...

Post by Hamilto » Wed, 18 Aug 2004 13:45:29

The middle tier does add the complication of sockets and/or DCOM. Setting up
socket server and setting COM identities is confusing for most users.

I agree with Dan however that it 'would be much simpler (to maintain 1
version) than compiling two versions of the application'.

Regards,

Hamilton Colyer-Long
Janusys
 
 
 

Looking for an approach...

Post by Heiko Tapp » Wed, 18 Aug 2004 21:18:24

> I'm in the same boat. I was going to go the DCOM/Datasnap route but the
clients

I haven't looked into D8 so far.
What are these limitations?

piece
versions

Yes. This is possible.
But I don't want to be dependent on technologie I do not need.
This makes the app harder to install and maintain.
BTW, what has to be present or has to be installed on the client to use DCOM
for example?


Heiko
 
 
 

Looking for an approach...

Post by Dan Palle » Thu, 19 Aug 2004 00:55:48


hold.
options

For D8 as a server, you can only use Datasnap via SOAP, no DCOM, sockets,
etc.

DCOM

I'm pretty sure that 2000 and up handle DCOM out of the box. I could be
wrong, though. I'm sure if they don't, it's a simple matter to add the
functionality.