Using the Small-World Model to Improve Freenet Performance

– Efficient data retrieval in a peer-to-peer system like Freenet is a challenging problem. In this paper we study the impact of cache replacement policy on the performance of Freenet. We find that, with Freenet’s LRU cache replacement, there is a steep reduction in the hit ratio with increasing load. Based on intuition from the small-world models and the recent theoretical results by Kleinberg, we propose an enhancedclustering cache replacement scheme for use in place of LRU. Such a replacement scheme forces the routing tables to resemble neighbor relationships in a small-world acquaintance graph -- clustering with light randomness. In our simulation this new scheme improved the request hit ratio dramatically while keeping the small average hops per successful request comparable to LRU. A simple, highly idealized model of Freenet under clustering with light randomness proves that the expected message delivery time in Freenet is O( n2 log ) if the routing tables satisfy the small-wo...

• Type: Conference
• Year: 2002
• Where: INFOCOM
• Authors: Hui Zhang 0002, Ashish Goel, Ramesh Govindan
• Keywords: Cache Replacement, Communications, Freenet’s LRU Cache, INFOCOM 2002, Replacement Scheme