Three-Tier And Auto-Commercial System

With the developments of distributed technology and the network, the applications of computer have penetrated in all fields. Two-tier C/S architecture can't meet the increasingly requirements and three-tier C/S architecture is one of the best choices when building open enterprise application systems. Meanwhile, middleware technology mushrooms. Three-tier and transaction middleware have been successfully applied in transaction processing systems, for example, in telecommunication, but is still unusual in commerce. Are they also applied to commercial management system? To the question, this paper researches and analyses to get positive result and apply to an instance.First, the development and key technology of three-tier structure > the conception, catalogs and selection of middleware are summarized.Second, the transaction middleware architecture is formally described by Z language. Z language can describe both the function and the actual system. The architecture of C/S based on transaction middleware is described, which is not a certain system, but a model of a class system or a software architecture style. The formalization research helps the further understanding of the essential of C/S system.Transaction middleware mainly offers interfaces to the local application. Many literatures show it uses shared memory to transfer messages with static assignment and queuing management. But the quantitative analyses of the capacity of shared memory andthe count of service process are never available. This chapter firstapplies the queuing theory into the communication of the middleware and draws conclusions by calculating, analyzing and comparing the parameters of six math models.And then basing on the three-tier structure, a supermarket management application system is investigated and designed by use of transaction middleware technology, and the auto management is realized.Finally, a mass of tests by man and tools prove that this system is up to satisfaction.