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We consider cluster-based network servers in which a front-end directs incoming requests to one of a number of back-ends. Specifically, we consider <i>content-based request distribution:</i> the front-end uses the content requested, in addition to information about the load on the back-end nodes, to choose which back-end will handle this request.(More)
CoMon is an evolving, mostly-scalable monitoring system for PlanetLab that has the goal of presenting environment-tailored information for both the administrators and users of the PlanetLab global testbed. In addition to passively reporting metrics provided by the operating system, CoMon also actively gathers a number of metrics useful for developers of(More)
This paper presents the design of a new Web server architecture called the asymmetric multi-process event-driven (AMPED) architecture, and evaluates the performance of an implementation of this architecture, the Flash Web server. The Flash Web server combines the high performance of single-process event-driven servers on cached workloads with the(More)
This article presents the design, implementation, and evaluation of IO -Lite, a unified I/O buffering and caching system for general-purpose operating systems. IO-Lite unifies <italic>all</italic> buffering and caching in the system, to the extent permitted by the hardware. In particular, it allows applications, the interprocess communication system, the(More)
Network researchers commonly use reverse DNS lookups of router names to provide geographic or topo-logical information that would otherwise be difficult to obtain. By systematically examining a large ISP, we find that some of these names are incorrect. We develop techniques to automatically identify these misnamings, and determine the actual locations,(More)
With the advent of large-scale, wide-area networking testbeds, researchers can deploy long-running distributed services that interact with other resources on the Web. The CoDeeN Content Distribution Network, deployed on PlanetLab, uses a network of caching Web proxy servers to intelligently distribute and cache requests from a potentially large client(More)
As the nature of Web traffic evolves over time, we must update our understanding of underlying nature of today's Web, which is necessary to improve response time, understand caching effectiveness, and to design intermediary systems, such as firewalls, security analyzers, and reporting or management systems. In this paper, we analyze five years (2006-2010)(More)
Detecting network path anomalies generally requires examining large volumes of traffic data to find misbehav-ior. We observe that wide-area services, such as peer-to-peer systems and content distribution networks, exhibit large traffic volumes, spread over large numbers of geographically-dispersed endpoints. This makes them ideal candidates for observing(More)
Scalable distribution of large files has been the area of much research and commercial interest in the past few years. In this paper, we describe the CoBlitz system, which efficiently distributes large files using a content distribution network (CDN) designed for HTTP. As a result, CoBlitz is able to serve large files without requiring any modifications to(More)
It is becoming increasingly common to construct network services using redundant resources geographically distributed across the Internet. Content Distribution Networks are a prime example. Such systems distribute client requests to an appropriate server based on a variety of factors---e.g., server load, network proximity, cache locality--in an effort to(More)