Constructing an optimal server set in structured peer-to-peer networks

To achieve high performance and resilience to failures, a client can make connections with multiple servers simultaneously and receive different portions of the data from each server in parallel. However, selecting the best set of servers from the set of all nodes that have the desired data is not a straightforward task, and the obtained performance can dramatically vary depending on the constructed server set. In this paper, we present two server selection schemes that generate optimal server sets with respect to the degree of interference(DOI) criterion and the worst link stress(WLS) criterion in a structured peer-to-peer network. After examining the correctness of the algorithms, we present simulation results demonstrating the benefits of the optimal server selection schemes. Through the simulation results, we conclude that the optimal selection schemes perform better than the random server-selection scheme in the following aspects: (1) load-balancing in the network and the worst-case link stress, (2) network resource used by the connections, including the number of links and total bandwidth, (3) response time, and (4) throughput of TCP connections.