LOBS: Load Balancing for Similarity Peer-to-Peer Structures

Abstract. The concept of peer-to-peer structures has recently been ap-plied on the problem of large-scale similarity search. This resulted in sys-tems where the computational load of the peers is of a high importance. Since no current load-balancing technique is designed for structures of this kind, we propose LOBS – a general system for load-balancing in peer-to-peer structures with time-consuming searching. LOBS is based on the following principles: measuring the computational load, separation of the logical and the physical level of the system, and detailed analysis of the load source to exploit either data relocation or replication. This work contains results of experiments we conducted using a proto-type implementation of LOBS. In these trials, we used a real-life dataset and we varied the number of peers and the distribution of the query traf-fic in the system. The results show that LOBS is able to cope with any query-distribution and that it improves both the utilization of resources and the performance of the query processing. The costs of balancing ar