N-tier architecture

[Kumar Vinay]

Hi folks
What is n-tier architecture.
bye
Vinay

[Peter den Haan]

Originally posted by Kumar Vinay:
Hi folks
What is n-tier architecture.
bye
Vinay

You know traditional client-server applications? "Fat" client applications on one side talking to a database server on the other? That's two-tier. Logic and presentation are inextricably tied up in the client application. This makes it difficult to change or enhance it.
In practice, anything more sophisticated than this is called n-tier, whether justified or not.
Specifically, in a J2EE context, an n-tier architecture means that the application layer has been split up in a thin client for the presentation (either a web browser driven by JSPs, or a Java application) talking to an application server with EJBs for the business logic. Which in turn talks to the database server.
That's three tiers; some people split their functionality up even further; all these schemes are called n-tier.
All rather simplified.
Peter