WAS v8.5 > Overview > Product architecture

Three-tier architectures


Three-tier architecture

  1. First tier

    Client presentation and user interaction. Enables user to interact with the second-tier processes. Clients do not access the third-tier services directly.

  2. Second tier

    Application logic layer that manage the application business logic. Permitted access to the third-tier services. Multiple client components can access the second-tier processes simultaneously. Manages transactions.

    For example, if several customers attempt to place an order for the same item, of which only one remains, the application logic layer determines who has the right to that item, update the database to reflect the purchase, and inform the other customers the item is no longer available. A lock can occur when an item is placed into a shopping cart, preventing other customers from considering it for purchase.

  3. Third tier

    Generally a database. Protected from direct access by the client components. Interaction occurs through the second-tier processes.


Related concepts:

WAS architecture


+

Search Tips   |   Advanced Search