ITR/SI: Adaptive Wide-Area Information Delivery

万维网的爆炸性流行和呈指数级增长的规模给互联网的内容交付基础设施带来了严重的压力。这种压力已经开始暴露出Web传统的客户端-服务器体系结构的低效和局限性。最近出现了一系列新机制和替代架构，包括Akamai等内容分发网络(CDN)和Napster等点对点覆盖网络。然而，尽管这些体系结构得到了快速部署和全球使用，但在许多情况下，人们对它们的行为知之甚少。这项研究项目的目标有三个。首先，将对现有互联网内容交付架构的有效性进行量化分析，特别关注(1)高速缓存基础设施、(2)内容交付网络和(3)点对点网络。其次，基于这些测量，将探索用于Web内容交付的新的或增强的体系结构的设计。第三，将实施、部署和衡量新的设计。一个特别的焦点将是大量使用自我测量和在线算法的自适应系统的设计和实现，例如，动态地优化请求路由、内容放置或对等覆盖网络的拓扑。总体而言，希望增加对内容交付体系结构的理解，并开发新的内容交付机制，极大地改善互联网的行为。

The explosive popularity and exponentially increasing scale of the World Wide Web has severely stressed the Internet's content-delivery infrastructure. This stress has begun to expose the inefficiencies and limitations of the Web's traditional client-server architecture. A progression of new mechanisms and alternative architectures have recently appeared, including content delivery networks (CDNs), such as Akamai, and peer-to-peer overlay networks, such as Napster. Despite the rapid deployment and global use of these architectures, however, little is understood about their behavior in many cases. The goals of this research project are threefold. First, the effectiveness of existing Internet content-delivery architectures will be quantitatively analyzed, specifically focusing on (1) cache infrastructure, (2) content-delivery networks, and (3) peer-to-peer networks. Second, based upon these measurements, the design of new or enhanced architectures for Web content delivery will be explored. Third, new designs will be implemented, deployed, and measured. One particular focus will be the design and implementation of adaptive systems that make heavy use of self-measurement and on-line algorithms, e.g., to dynamically optimize request routing, content placement, or the topology of the peer-to-peer overlay network. Overall, the hope is to increase the understanding of content-delivery architectures and to develop new content-delivery mechanisms that greatly improve the behavior of the Internet.