An ant colony model based replica consistency maintenance strategy in unstructured P2P networks

To improve file availability and peers' retrieval efficiency, many P2P networks adopt file replication techniques to distribute files and their replicas. Thus how to maintain the replica consistency has been an important research focus, especially in the P2P networks with writable and dynamically changeable files. Existing researches suffer from the shortcomings of either needing more update messages or having lower update success rates. This paper proposes a novel replica consistency maintenance strategy based on an ant colony model. We first define an ant's actions and states, and then we use ants to update replicas in their walking forward and update file's pheromones in their returning process. We discuss how to tackle the churn problem when an ant returns. The simulation results show that our strategy could reduce the update cost and the impacts caused by churn in replica consistency maintenance in unstructured P2P networks. (C) 2014 Elsevier B.V. All rights reserved.