Implementing a 3-tier client-server system

[Guest]

Mokles:

I had the same question, when I went from web-based architecture with ASP
and COM, to .NET development. Actually to implement the "middle tier" or
business layer in .NET, you should create stand alone classes either within
your project, or as a separate object that creates a dll that you reference
from your project.

A webservice is a way to communicate with your dll, if you can't reference
it locally. Also, a webservice fits into an SOA architecture, which is adds
an additional layer to traditional 3-tier systems.

Josh.

 

[mokles]

All,

We are trying to implement a 3-tier Client/Server Widows system in .Net.
We have found that the middle tier can be implemented using Webservice or
remoting. We are just wondering what other options we may have to implement
the middle tier. Any help will he highly appreciated.

Thanks,
Mokles

 

[Tobin Harris]

Hi Mokles,

As josh said, you could just put your middle tier objects in a separate DLL
(or even just a separate namespace, if it's a small project). Setting up
remoting, a web service layer, or any other layer is going to be more work
of course - so I'd make sure I need it. If you can get away with having an
ASP.NET GUI layer referening your business logic DLL, then that's a nice
simple start IMHO.

Tobes

 

[mokles]

Thanks, Tobes and Josh for the reply.

Just to make sure that I understand, after building the middle tier objects
into DLLs I have to put them on a machine (called Application Server?). Then
from my Front End project I have to create a reference to the DLLs on the
Applicaion server and use the DLL in the Front End project. I am assuming
that the Application Server and the Front End appliction project will be on
the same Windows domain. I will try this out.

Thanks again.

Mokles

 

[Tobin Harris]

Hi Mockles

Usually the n-Tier refers to logical tiers - meaning layering in the *code*.
For some projects, it's perfectly acceptable to put all your tiers on a
single server. I'm no expert on this, so perhaps others can advise.

Other ways of scaling are to have your GUI and business logic on one server
and the database on another. You could create a dedicated middle tier
server, but then you'll need to consider mechanisms such as remoting or web
services to allow this tier to be used by other processes on other machines.

It usually makes sense to put your data as close to your application as
possible, and also sense to give your business layer fast access to your
data. I suppose it depends on how big your application is as to where you
create physical separations.

Tobes

 

[mokles]

Thanks Tobes.
Your explanation helped a lot. Now I have to find out if remoting or web
services are the only options I have if I want to have a dedicate middle
tier server.

Thanks again.
Mokles

I have to explore this little