Distributed Application Development
When
we develop our 3-tier application in a Microsoft environment we'll effectively
be developing using the Windows
Distributed interNet Architecture (Windows
DNA). This term refers to an n-tier logical application
model, coupled with a framework designed to efficiently design and develop distributed
applications. Crucially, it encompasses a number of tools and services that
are enabling technologies – they make it possible to concentrate on the business
requirements and code of a distributed application, and not have to worry too
much about the plumbing of what goes where and how it works.
So, for example, some of the services
make it simple to make certain parts of our project take part in transactions,
and those services will control any transactions that take place. We just have
to concern ourselves with deciding which parts of our project should take part
in transactions, not how to control transactions in software.
The Windows DNA concept is now evolving
into Windows
DNA 2000 which is both a marketing term devised by
Microsoft to help promote the Windows 2000 family of operating systems and a
reference to the development of the original tools and services into a complete
development platform.
The Microsoft Solutions Framework (MSF) Application Model
we referred to above consists of a logical 3-tier services-based approach to
designing and developing software applications, using Windows DNA.
The overall architecture looks very familiar.
However, as we'll discover, the tools and services that underpin the whole architecture
make developing complex applications quite straightforward:
Let's overview the tools and technologies
associated with this approach. We won't be making use of all these technologies
(some of them are for more advanced development than we're doing here), but
we'll quickly introduce most of the names.