SCALAR: Scalable Architecture for Replication of Data

提案编号：CCR-9902023标题：SCALAR：WebPI上复制的可扩展体系结构：Peter Scheuermann项目摘要：万维网的广泛使用和访问Internet的方便性正在彻底改变我们对分布式系统的需求。网络使用规模的指数级增长对互联网的容量造成了极大的压力，导致Web服务的性能和可靠性降低。复制是一个主要的技术，已被提出来克服这些问题。这个项目将集中在一个原型系统的发展，将提供一个可扩展的架构，在Web上的复制。 一个新的客户端/服务器体系结构，将允许用户透明的地理复制的调查。在该系统中，客户端作为签名的小应用程序下载到商业上可用的浏览器。支持servlet的Web服务器可以直接用servlet扩展，也可以用支持servlet的服务器端代理扩展。与其他提出的Web体系结构不同，客户机和服务器都在此体系结构中发挥作用，服务器机器确定要复制/迁移的文档以及文档的最佳位置，而客户机则根据对服务器先前响应时间的估计来选择最佳服务器提交请求。将开发基于聚类技术的启发式算法，以确定作为一个单元进行有益迁移/复制的文档集。

Proposal Number : CCR-9902023TITLE : SCALAR : Scalable Architecture for Replication on the WebPI: Peter ScheuermannProject Summary:The wide use of the World-Wide Web and the ease of access to the Internetare changing drastically our requirements in distributed systems. The exponentiallygrowing scale of use of the Web is stressing the capacity of the Internet and leads to poor performanceand low reliability of Web service. Replication is one of the major techniques that have beenproposed to overcome these problems.This project will focus on the development of a prototype system that willprovide a scalable architecture for replication on the Web. A new client/server architecturethat will allow for user-transparent geographic replication isinvestigated. In this system, the clients are downloaded as signed applets to commercially available browsers. Web servers that supportservlets can bedirectly extended with servlets, otherwise with server-side proxies thatsupport servlets. Unlike other proposed Web architectures, both clients and servers take activeroles in this architecture.Server machines determine the documents to be replicated/migrated and bestlocations for the documents, while client machines choose the best server to submit theirrequests based on estimates of the servers' prior response times. Heuristicalgorithms based on clustering techniqueswill be developed in order to determine sets of documents that bebeneficially migrated/replicated as a unit.