Simple Efficient Load-Balancing Algorithms for Peer-to-Peer Systems

Load balancing is a critical issue for the efficient operation of peerto-peer networks. We give two new load-balancing protocols whose provable performance guarantees are within a constant factor of optimal. Our protocols refine the consistent hashing data structure that underlies the Chord (and Koorde) P2P network. Both preserve Chord's logarithmic query time and near-optimal data migration cost. Consistent hashing is an instance of the distributed hash table (DHT) paradigm for assigning items to nodes in a peer-to-peer system: items and nodes are mapped to a common address space, and nodes have to store all items residing closeby in the address space. Our first protocol balances the distribution of the key address space to nodes, which yields a load-balanced system when the DHT maps items "randomly" into the address space. To our knowledge, this yields the first P2P scheme simultaneously achieving O(logn) degree, O(logn) look-up cost, and constant-factor load balance ...

• Type: Journal
• Year: 2006
• Where: MST
• Authors: David R. Karger, Matthias Ruhl
• Keywords: Address Space, Data Structure, MST 2006, Provable Performance Guarantees