Faster Content Access in KAD

Many different Distributed Hash Tables (DHTs) have been designed, but only few have been successfully deployed. The implementation of a DHT needs to deal with practical aspects (e.g. related to churn, or to the delay) that are often only marginally considered in the design. In this paper, we analyze in detail the content retrieval process in KAD, the implementation of the DHT Kademlia that is part of several popular peer-to-peer clients. In particular, we present a simple model to evaluate the impact of different design parameters on the overall lookup latency. We then perform extensive measurements on the lookup performance using an instrumented client. From the analysis of the results, we propose an improved scheme that is able to significantly decrease the overall lookup latency without increasing the overhead.