面向资源广域分布环境的数据复制定位

在资源广域分布的环境中，数据复制和定位是提高数据访问性能的关键技术之一。该文提出了一种分布式、自适应复制定位机制(ALM)，该机制基于复制定位信息分发和网络缓存思想，采用分层的分布式复制目录系统和软状态协议实现。其中，复制目录系统分布存储复制定位信息，软状态协议分发复制定位信息及其改变。因此，ALM具有很好的分布性和自适应性。ALM在复制目录的设计中引入了Web缓存的功能，使得ALM较其它机制具有更广泛的适用性。

Data Replica Location in Lager-scale Wide Area Resource Distributed Environment

Within large-scale wide area resource distributed environments, data replica location is one of the key techniques in promoting the performance of data accessing. In this paper, a distributed adapting data replica locating mechanism (ALM) is proposed. The design is based on the distributing location information and the idea of Web cache. The building blocks include a hierarchical distributed replica catalogue (RC) system and the soft-state protocol. The hierarchical distributed replica catalogue system is responsible for storing replica location information. The soft-state protocol is responsible for propagating distributing and updating replica location information. Therefore, the design obtains genuine decentralization and adaptation. The paper also introduces the function of caching Web pages to the RCs. So ALM can be used widely.