A Study On Distributed Data Access Based On Mobile Agent

Mobile agent is a calculation entity that encapsulates the code, the state and the data .It can move from one host to another in the network acting on one's own, and finish the designated task on behalf of users. Mobile agent technology involve such a great deal of fields as computer network , distributed system and artificial intelligence.Because such characteristics as moving , independence and harmony ,etc, the application in the distributed system show good prospect and superiority .The purpose of this thesis is to explore the system construction problems, which were met when the mobile agent was applying in distributed computation. Mainly studied constitutes and structure of the distributed system based on the mobile agent technology, also its production been further extended and consummated.In this thesis, generally analyzed the concept, constitutes, key technology and security issues of the mobile agent. Moreover discussed the design model and programming method based on the mobile agent system. The service subsystem was made up of the agent server, some agent service in the network. All agent service must be registered in the intermediary server, which managed the agent service. The users asked the agent service to execute tasks within the network via the intermediary server. They need not concentrate on the concrete implement of the task. So agent system can provide uniform, flexible, application level computation service. Through studying existing distributed object technology, and comparing with mobile agent technology, we proposed the scheme increasing ORB layer in the mobile agent. This project realized application of mobile agent in the distributed object service, thereby mobile agent technology and exist network system were conjoined effectively. Further more, discussed the server detecting the network,analyzed the existing disadvantage to detect network through transferring the operation system in the past. And suggested a new communication method between servers, designed communication format between servers. This method included the load of objective host computer and connectivity information of the network, so the server can forecast network situation well. At the same time to help resolving the data exchange in the isomerous system, this thesis also involved the XML knowledge, and transformed XML and local data express each other. Finally the model mentioned in this thesis has been experimented on the LAN, and obtained approving effect compared with distributed object technology.