A path tracking search algorithm based on the credibility of node service ability

Designing an efficient search algorithm is a key challenge in unstructured peer-to-peer networks in order to reduce redundant messages in the search process. Addressing the problem, in this paper, a path tracking search algorithm based on the credibility of node service ability(CNSA) is proposed. we utilize the credibility of node service ability as heuristic information to probabilistically guide the search. The credibility of node service ability is a new neighbor selection criterion which allows a peer to evaluate the credibility of its each neighbor based on the successful feedbacks from previous searches and the service capability of each neighbor node itself. Meanwhile, aiming to eliminate the repeat messages forwarding and reduce the number of redundant messages, the path tracking mechanism and the local messages caching mechanism are combined into CNSA. Our extensive simulation results show that CNSA can reduce the number of redundant messages, increase the query hit rate and adaptation to the dynamic characteristics of P2P networks.