基于Mobile Agent的信息服务模型

提出了一个基于Ｍｏｂｉｌｅ Ａｇｅｎｔ技术的信息服务模型，并分析了其信息服务体系所具有的优势和应解决的关键技术问题，最后简单介绍基于此模型的信息检索实验和当前Ｍｏｂｉｌｅ Ａｇｅｎｔ技术的发展现状和发展趋势。

THE INFORMATION SERVICE MODEL WITH MOBILE TECHNOLOGY

The traditional information service,such as WWW and FTP, are based on Client/Server architecture. In Client/Server paradigm,the client and the server must keep persistent connection and work synchronously when a client application accesses a server.Therefor,the system based on the Client/Server paradigm relies on network's bandwidth heavily.But in the environment of Internet,which is characterized by large scale,heterogeneity,low bandwidth,distributed sources and unsteady connection,the system with Client/Server architecture will not operate perfectly. Mobile Agent is a new agent technology characterized by mobility and intelligence. Mobile Agent can move to other nodes of the network,perform its tasks on remote hosts and execute dynamically,asynchronously and parallely.Bringing the idea of motion into agent areas makes the agent technology have the capability of solving some problem that Client/Server paradigm could not solve. The Mobile Agent technology can change traditional information service mode and solves the problem of heterogeneity,low bandwidth and unsteady connection.This paper introduces an information service model with Mobile Agent technology and its working flow.The information service system that adopts Mobile Agent technology consists of users' Mobile Agents,Agent Host,Information Service and Agent Dock commonly.Mobile Agents are the entities to fulfill tasks,and will run in the environment established by the Agent Host. The Agent Host resides in information server side. Agent Host would establish the accessing interface and execution environment for each agent,and implement the agent's migration among modes using Agent Transfer Protocol(ATP).When agents run in a server,they can interact with service resources directly through Agent Host instead of network transmission. Agent Host is the supporting environment of agent at server side and can exist with traditional information service server such as Web Server and FTP Server in the form of plug in unit instead of modifying original service system and securitymechanism.So,the information service systems based on this model are able to provide not only traditional information service for common users but also Mobile Agent service for agent users.At last,an experimental system based on that model is presented.The result of experiments shows that performances' improvement can be achieved by that model; both the latency and network traffic are reduced significantly.