A Distributed Load Balancing Algorithm for Structured P2P Systems

In structured P2P system, DHT abstraction and the heterogeneity of node capacity could result in a load imbalance problem. Existing load balancing approaches have two limitations. First, they do not take the link latency into account when moving loads, thus loads may be transferred between two nodes with large link latency. Second, they heavily rely on some nodes of fixed logical locations in the system, which could overload these nodes and make them vulnerable. This paper presents a distributed load balancing algorithm. Each peer node periodically aggregates local loads information based on local neighborhood information, and a heuristic algorithm is used when transferring loads from heavy nodes to light nodes. Our algorithm not only utilizes the proximate relationships of nodes in the physical networks, but also manages to achieve a good tradeoff between the quality of load balance and the load movement cost. The results of our intensive simulation experiments show that our algorithm can not only achieve a good load balance, but also save the bandwidth by more than 23%.