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Unformatted text preview: 1 The Case for Cooperative Networking Venkata N. Padmanabhan * Kunwadee Sripanidkulchai Microsoft Research Carnegie Mellon University Abstract In this paper, we make the case for Cooperative Network- ing (CoopNet) where end-hosts cooperate to improve net- work performance perceived by all. In CoopNet, coopera- tion among peers complements traditional client-server com- munication rather than replacing it. We focus on the Web flash crowd problem and argue that CoopNet offers an ef- fective solution. We present an evaluation of the CoopNet approach using simulations driven by traffic traces gathered at the MSNBC website during the flash crowd that occurred on September 11, 2001. I. INTRODUCTION There has been much interest in peer-to-peer comput- ing and communication in recent years. Efforts in this space have included file swapping services (e.g., Napster, Gnutella), serverless file systems (e.g., Farsite , PAST ), and overlay routing (e.g., Detour , RON ). Peer-to-peer communication is the dominant mode of com- munication in these systems and is central to the value pro- vided by the system, be it improved performance, greater robustness, or anonymity. In this paper, we make the case for Cooperative Net- working (CoopNet), where end-hosts cooperate to improve network performance perceived by all. In CoopNet, coop- eration among peers complements traditional client-server communication rather than replace it. Specifically, Coop- Net addresses the problem cases of client-server commu- nication. It kicks in when needed and gets out of the way when normal client-server communication is working fine. Unlike some of the peer-to-peer systems, CoopNet does not assume that peer nodes remain available and willing to cooperate for an extended length of time. For instance, peer nodes may only be willing to cooperate for a few min- utes. Hence, sole dependence on peer-to-peer communica- tion is not an option. The specific problem case of client-server communica- tion we focus on is flash crowds at Web sites. A flash crowd refers to a rapid and dramatic surge in the volume of requests arriving at a server, often resulting in the server being overwhelmed and response times shooting up. For instance, the flash crowds caused by the September 11 ter- rorist attacks in the U.S. overwhelmed major news sites such as CNN and MSNBC, pushing site availability down close to 0% and response times to over 45 seconds . * http://www.research.microsoft.com/ e padmanab/ http://www.andrew.cmu.edu/ e kunwadee/. The author was an intern at Microsoft Research through much of this work. Flash crowds are typically triggered by events of great in- terest whether planned ones such as a sports event or unplanned ones such as an earthquake or a plane crash....
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This note was uploaded on 12/08/2011 for the course CS 525 taught by Professor Gupta during the Spring '08 term at University of Illinois, Urbana Champaign.
- Spring '08