Mobile Agent Model for Flexible Distributed Systems.

灵活分布式系统的移动代理模型。

基本信息

批准号：
14580457
负责人：
TAKIZAWA Makoto
金额：
$ 2.24万
依托单位：
Tokyo Denki University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2003
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14580457/
关键词：
Mobile Agent Peer-to-Peer(P2P) System Transactional agent Fault Tolerant Quality of Service (QoS)Distributed System Database System Client Server System 交渉プロトコル自律性やわらかい分散システム競合演算

项目摘要

In traditional client-server applications, application programs and objects are distributed into clients and servers, respectively. On the other hand, every computer named servant is peer which can have programs and objects in peer-to-peer (P2P) systems. In addition, huge number and various types of computers are interconnected in networks, ranging from high-performance, high-reliable computers like database servers to less-reliable personal computers and mobile stations. It is critical to discuss how to develop and execute reliable applications on databases in P2P systems. In database applications, transactions manipulate objects so as to satisfy ACID (atomicity, consistency, isolation, and durability) properties. In traditional database systems, objects are locked or transactions are timestamped to serialize multiple transactions. If objects in multiple computers are manipulated, the atomic manipulation of multiple computers has to be supported in the two-phase commitment (2PC) proto … More col.In this research, we discussed a novel type of agent model, transactional agent model to manipulate objects in multiple computers with types of commitment constraints. A transactional agent is defined to be a mobile agent which moves around computers and locally manipulates objects in one or more than one computer with type of commitment constraint. In addition, an agent negotiates with another agent if the agents manipulate a same object in a conflicting manner. Through the negotiation, each agent autonomously makes a decision on whether the agent holds or releases the objects. A transactional agent autonomously finds another destination computer if a computer where the agent to move is faulty. In this research, we discussed how to implement transactional agents in Java Aglets and Oracle database systems. We showed the evaluation of the mobile agent-based transaction systems for applications. If Aglets classes are a priori loaded, the transactional agents can manipulate object servers more shortly than the traditional client-server model. Less

在传统的客户端-服务器应用程序中，应用程序和对象分别分布在客户端和服务器中。此外，每台名为“仆人”的计算机都是对等计算机，它们可以在对等（P2P）系统中拥有程序和对象。数量庞大、类型多样的计算机在网络中互连，从数据库服务器等高性能、高可靠性计算机到可靠性较低的个人计算机和移动站，讨论如何在数据库上开发和执行可靠的应用程序至关重要。在P2P系统中。数据库应用中，事务操作对象以满足ACID（原子性、一致性、隔离性和持久性）属性，在传统的数据库系统中，对象被锁定或事务被加时间戳以序列化多个计算机中的对象。两阶段承诺 (2PC) 原型必须支持对多台计算机的操作。在这项研究中，我们讨论了一种新型代理模型，即事务代理模型，用于在具有承诺约束类型的多台计算机中操作对象。事务代理被定义为移动代理在计算机周围移动并在一台或多台计算机中以承诺约束类型本地操作对象。此外，如果代理以冲突的方式操作同一对象，则代理与另一个代理进行协商。代理自主地决定代理是否保留或释放对象。如果要移动的代理所在的计算机出现故障，事务代理将自主寻找另一台目标计算机。在本研究中，我们讨论了如何在 Java Aglet 和 Oracle 中实现事务代理。我们展示了数据库系统的评估。如果 Aglets 类是先验加载的，则事务代理可以比传统的客户端-服务器模型更快地操作对象服务器。