Efficient, proximity-aware load balancing for structured P2P systems

Structured peer-to-peer (P2P) systems address the load balancing issue in a rather naive way, by simply resorting to the uniformity of the hash function utilized to generate object IDs. Such a random choice of object IDs could result in O(log N) load imbalance. We propose an efficient, proximity-aware load balancing algorithm for such systems. To our knowledge, this is the first work to utilize the proximity information to guide load balancing. In particular, our main contributions are: (1) A self-organized, fully distributed K-nary tree structure is constructed on top of a DHT for load balancing information collection/dissemination and load reassignment. (2) Load balancing is achieved by aligning those two skews in both load distribution and node capacity inhere in P2P systems - that is, have higher capacity nodes carry more loads. (3) Proximity information is utilized to guide load balancing such that virtual servers are assigned and transferred between physically close heavy nodes and light nodes, thereby minimizing the load transferring overhead and making load balancing fast and efficient.