1.2.5 Tiered Application Architecture

Computing environments often involves multiple hardware platforms and operating systems. Application programs are distributed across these platforms. To facilitate a distributed processing model, developers introduced tiered architectures.

Tiered architectures involve the separation of the different processing segments of an application:

Presentation Logic (Graphical Interfaces, etc.)

• This logic is handled by specialized client (PC-based) applications with robust graphical interfaces that simply control the presentation of information (such as a Web browser).

Application or Business Processing Logic

• This logic may reside on a client as a called function or may reside on the server as a remote procedure call but is often stored as a separate module. Application servers may support the application logic but contain no databases.

Database or Business Rule Logic

• This logic may be entered into a specific database manager so that a referential integrity check or business rule triggers are invoked by the database manager and not the application programs.

 

A tiered architecture provides a significantly more flexible computing model but introduces a number of new challenges. These layers in the architecture are often written in different languages with different tools. They reside on different platforms and execute under different operating systems. The final solution may still lack portability because of the platform specific requirements written into each layer.

A development environment with a properly architected solution can easily address these complexities and simplify application development. The 1.2.6 LANSA Application Architecture simplifies application development.

Also See

1.2.4 Traditional Application Architecture