Study On Layer Pattern Under Distributed Application Environment

Along with the boom of information technology, the distributed applications based on Internet become more and more complex, and the design of software architecture becomes more difficulty. A bad-designed architecture often results in a bad performance of the whole system. Layer pattern helps to construct the architecture of applications which can be divided into some groups of sub-task and each group is on a specifically abstract layer. With .NET framework, the work of constructing a web-based application by layer pattern becomes easier. As Web Services technology becomes more mature, enterprises need to provide services to their partners and integrate the services of partners into their own applications.To accommodate with this service-oriented requirement and make use of the existed there-layered pattern, duties related with other services can be added to each layer, thus three-layered application pattern is expanded to three-layered services application pattern. Application logic is divided into a group of cooperated services, each service provides a part function of the system. Each service of the business layer denotes a service interface that is implemented independent. Applications that take advantage of expanding data access layer can use service gateway to communicate with other services. If application logic is very complicated, user interface procedure component can be viewed as a part of the user layer so that the logic can be encapsulated and reused.An enterprise application based on Web is implemented according to the layer pattern, it adapts three-layered services application pattern to design system architecture. The system, which has powerful interaction function, uses advance B/S structure to overcome the infirm interaction of browsers and realize the integration of heterogeneous systems and data sharing. A few of transaction modules including database transaction, manual transaction and auto transaction are put forward aiming at the system. Microsoft Application Center Test tool is used to test and analyze the transaction modules. The merits and defects of the transaction modules are summarized and the environment suited with the transaction modules is also offered.