BorlandTalk.com

Kevin · Guest

Hi all,

Could any one please guide us or create a sample program that runs as
follows:
The aim is to create a sample n tier application, which is scalable and
extensible using Delphi. The sample application consists of the following:

1. Windows or web application (as front end running on the client machine)
2. Web Service (running on the web server)
3. Application Server (running on a separate machine)
4. Database Server (running sql server or oracle)

The Front end should connect via internet to the web service. The web
service should in turn talk to the Application Server, which in turn talks
to the database server. The result from the database server is then passed
to the application server and then to the web service and the web
application (front end). Remember that, each of the four components listed
above should be capable of running on separate servers as well as on a
single machine. That makes the entire application scalable and gives room
for load balancing.

We have done a similar application in VB .Net and want to create a similar
application using Delphi. We believe that Delphi would be a lot faster and
easier way of accomplishing the same. Please help us get this project done
using Delphi

Thanks and Regards
Kevin

Steve Ball · Guest

Kevin,

I'm in the middle of doing a web application. I've had to read up a little
on doing Multi-threaded applications, but its worth it. I'm making the
application using Intraweb.

As for being scalable. There is some really cool stuff you can do using
client datasets (as long as you make them read / write safe (but thats
really easy using a TMultiReadExclusiveWriteSynchronizer) by cloning them. I
keep one in memory on the server in a global data module and then clone them
where needed. (it also keeps the appliation fast as they only use one point
in memory).
The other really cool think with the intraweb application is that it auto
creates a user session (this is where you store data that you need to keep
seperate from other connection. (eg user name, variables that you need to
use).

I'd really recommend reading up on:
Cloning Clientdatasets. http://bdn.borland.com/article/0,1410,29416,00.html
Intraweb. http://bdn.borland.com/article/0,1410,29650,00.html
http://www.atozedsoftware.com/intraweb/download/
I'd also recommend spending out the small amount they charge for the
Intraweb training manual at http://www.falafelsoft.com Its been one of the
best things I've recently brought.

Cary Jensen has also done some really good sessions on 10 really cool things
you can do with Intraweb, I'd recommend looking out for such sessions.

On the intraweb side, if you have D7 you can get 5.1 free from
AtoZedSoftware but I'd recommend looking at buying IW6 as it has some really
cool extras.

Hope that helps.
Good luck with the project,

Steve

"Kevin" <cute_brains (AT) yahoo (DOT) co.in> wrote

Kevin · Guest

Thanks a million for your inputs Steve.

We'd request everyone out there, who have done doctorates in developing such
legacy n-tier applications to share your knowledge on this. We're sure that
everyone that's hoping to develop scalable n-tier applications would benefit
from your advice.

Please share your thoughts and experiences.

Thanks,
Kevin.

"Steve Ball" <SteveBall (AT) noSpam (DOT) uku.co.uk> wrote

Brian Cook · Guest