Adaptive Load Balancing for Lookups in Heterogeneous DHT

Abstract

In DHT based P2P networks, the heterogeneity of node capacity and the skewness in query pattern could result in lookup load imbalance. Indegree adjustment is an effective, light-weighted and heterogeneity-aware approach to balance lookup traffic in local area, but not globally. In this paper we present a hybrid algorithm combining in degree adjustment and virtual server (VS) approaches to address both local and global lookup imbalance in DHT networks. We divide local nodes into zones, and select strong nodes to form a virtual server group (VSG). Hot zones can apply for virtual servers from VSG in order to distribute load in system wide. Nodes and VSs in the zones use indegree adjustment to maintain zone balance. We can therefore significantly improve the load balancing of traffic in these systems, and consequently their performance.Results from experimental evaluation demonstrate the effectiveness of our approach.