Research Of Multi-tier Distributed System Based On Mobile Agent

Most multi-tier distributed systems are composed of components which are based on client-server paradigm, such as COM/DCOM/COM+, Enterprise Java Beans (EJB) and CORBA. These components can only move data between clients and server, so the objects are silly and cannot adapt to dynamic network. However, mobile agents haven't these disadvantages, they are capable of migrating autonomously from one host machine to another. If applying mobile agents to multi-tier distributed systems, the systems' performance should be increasing.This thesis explores two methods to develop multi-tier distributed systems based on mobile agents, the first is to integrate mobile agents into popular component architectures, the second is to build multi-tier distributed systems that only rely on mobile agents. For more discussing of the first method, this thesis explains how to insert Mobile Agent Application Service Tier into multi-tier architectures, which encapsulates transaction logic over a heterogeneous environment. Then a new mobile agent system named Multa is presented as a better system for multi-tier systems. Multa improves the procedure of mobile agent's running and design, while reduces the difficulty of development.Based on the front works, a transaction management subsystem for a power market is design and implementation. In the test time, the subsystem can fulfill the design target.