Research And Implementation Of Object-Oriented Distributed Middle Ware

As the rapid development of computer network technologies, the distributed applications are widely used in various enterprises. Distributed computing systems have various advantages, compared with concentrated ones, as the following: Collaboration between applications can be reached through interoperating;Performance can be improved through distributed parallel processing;Availability can be promoted by using duplication technology;Scalability can be improved through component and dynamic configuration technologies;Cost-performance ratio can be reached through resource sharing.In distributed systems, the heterogeneous entities are existed using different platforms or using different programming languages. Middleware provides distributed objects with the ability of transparency and interoperability even when these differences existed. Therefore, middleware has become an important research field in the distributed computing area.This thesis focuses on studying the application of middleware theoretically and practically. In this dissertation, principles of middleware are introduced. Then three major object-oriented middleware technologies have been discussed, including COM/DCOM/COM+, J2EE and CORBA. The architecture, interaction between client and server and system-level service provision of them are discussed and compared. ACS, the Application Control System, is an middleware product developed for International Billing Clearing System of China Mobile Roaming Clearing House. Technologies, including loading balance in distributed system, distributed transaction and oriented object methods, which discussed in this thesis, have been introduced in the designing and implementation of ACS system. This thesis finish the following working:We analyze the theory of load balancing and provide a load balancing model . a load balancing agrithm based on overall expected delay routing is implemented in ACS.the experiment results shows that the average response time of job and the system resource utilization can be optimizedIn ACS,distributed transaction is designed and implemented for the roaming file's processing,two phase commit proctol is used ,which can ensure the atomic of distributed transaction commit,recover the exception quickly and improve the system's reliability.