Algorithms for Performance Optimization in Peer-to-Peer Systems

Overview

Peer-toPeer (P2P) systems enable scalable wide-area storage and retrieval of information and will support the rapid development of a wide variety of Internet-scale applications ranging from naming systems and file systems to application-layer multicast. By their very design, these systems tradeoff some aspects of performance (latency or availability) in order to achieve their desired functionality. In structured P2P systems, lookup latency suffers since there is typically no correspondence between the overlay hop and the underlying topology. In unstructured P2P systems, because there is no correspondence between nodes and data items, one needs to sacrifice availability (i.e., hit ratio) for reasonable lookup latency and routing table size.

Our position is that these tradeoffs can be recovered through simple incremental techniques that a) have rigorous theoretical underpinnings, and b) do not sacrifice any functionality of the original system design and require relatively few changes. In this project we design, analyze, and test new algorithms which adhere to this philosophy.

People

• Hui Zhang
• Ashish Goel
• Ramesh Govindan

Publications

• Ashish Goel, Ramesh Govindan, Hui Zhang. Improving Lookup Latency in Distributed Hash Table Systems using Random Sampling. To appear in ACM/IEEE Transactions on Networking.
• Hui Zhang, Ashish Goel, Ramesh Govindan. Using the Small-World Model to Improve Freenet Performance. Computer Networks Journal. Volume 46, Issue 4, Page 555-574, November 2004.
• Hui Zhang, Ashish Goel, Ramesh Govindan. An Empirical Evaluation of Internet Latency Expansion. To appear in ACM SIGCOMM Computer Communication Review.
• Hui Zhang, Ashish Goel, Ramesh Govindan. Incrementally Improving Lookup Latency in Distributed Hash Table Systems. ACM SIGMETRICS, 2003.
• Hui Zhang, Ashish Goel, Ramesh Govindan. Using the Small-World Model to Improve Freenet Performance. IEEE INFOCOM, 2002.