Applying a diffusive load balancing in a clustered P2P system

Although a large number of users are using P2P systems, the ability of these systems to provide services with quality is questioned. A load balanced P2P system can provide services with smaller failure rate and better performance; hence, service quality of the system can be improved. Cluster systems have been adopted for services which are tolerant to faults. Although a cluster structure improving the reliability and robustness of a P2P system, the load unbalancing problem still remains because of the heterogeneities of nodes and requests. Existing dynamic load balancing mechanisms in P2P systems require extra connections and overhead on aggregating the load status from the nodes. We propose diffusive load balancing in a clustered P2P system, where a global balance is achieved through balancing the neighborhoods of all clusters within the existing overlay network. We simulated three load balancing schemes: directory-initiated, sender-initiated, and receiver-initiated; from an initially unbalanced situation, the results show that diffusive load balancing can achieve a global balance comparable to a centralized directory scheme, and the distributed directory-initiated scheme provides better results than the senderor receiver-initiated schemes.