Distributed
application architecture
Distributed application development, also called multitier
development, offers a natural way to separate the user interface
components of an application from the business logic that the application
requires. By centralizing business logic on a middle-tier server, you can
reduce the workload on the client and control access to sensitive
information.
In a distributed application, the client and server work together to
perform tasks for the business user. The client handles all interactions
with the user while the middle-tier server provides background services to
the client. Typically, the middle-tier server performs most of the
processing and database access. To invoke the services of the server, the
client calls a method (or function) associated with a component (or
object) that resides on the server.
Partitioned applications
Client-side logic for enterprise applications must be as small and
efficient as possible to conserve network bandwidth. To accomplish this
goal, applications are partitioned into three parts: presentation,
business logic, and database access. The database resides on the bottom
tier of the enterprise system to maintain and secure the organization’s
information assets. The business logic resides in the middle tier or
server. The presentation is on the user’s desktop, or top tier, or is
dynamically downloaded to the user’s desktop.
The server is then responsible for executing and securing the vast
majority of a corporation’s business logic. This makes it a critical
component in the network-centric architecture. The client communicates
with the server, calling middle-tier components that perform business
logic.
Web application architecture
A Web application is a variation of the distributed architecture
where the client is hosted in a Web browser. PowerBuilder provides a
couple of technologies for building Web applications. The architecture of
your application varies depending on which technologies you decide to
use.
For more information, see Web Application Development with
PowerBuilder