Small-World Overlay P 2 P Networks : Construction and Handling Dynamic Flash Crowd

In this paper, we consider how to “construct” and “maintain” an overlay structured P2P network based on the “smallworld paradigm”. Two main attractive properties of a smallworld network are (1) low average hop distance between any two randomly chosen nodes and, (2) high clustering coefficient. A network with a low average hop distance implies a small latency for object lookup. While a network with a high clustering coefficient implies the underlying P2P network has the “potential” to provide object lookup service even in the midst of heavy object traffic loading, for example, under a flash crowd scenario. In this paper, we present the SWOP protocol of constructing a small-world overlay P2P network. We compare our result with other structured P2P networks such as the Chord protocol. Although the Chord protocol can provide object lookup with latency of complexity, where is the number of nodes in a P2P network, we show that the SWOP protocol can further improve the object lookup performance. We also take advantage of the high clustering coefficient of a small-world P2P network and propose an object replication algorithm to handle the heavy object traffic loading situation, e.g. under the dynamic flash crowd scenario. We show that the SWOP network can quickly and efficiently deliver the “popular” and “dynamic” object to all requested nodes. Based on our knowledge, this is the first work that addresses how to handle the “dynamic” flash crowd scenario on a structured P2P