Query Mechanism for File Correlation in Cooperative Replica Prefetching

Abstract

副本协作预取是一种网格副本复制策略,旨在通过获取隐性高价值文件进一步降低数据访问延迟.副本协作预取的关键在于隐性高价值文件的确定和获取,因此,提高隐性高价值文件获取的速度能够大幅度提升副本协作预取的性能.利用DHT(distributed hash table)组织网格节点,以快速定位隐性高价值文件查询所必需的文件相关性信息.针对隐性高价值文件的特殊查询模式,提出基于预取规则树的文件相关性信息存储结构及其查询机制,以提高查询效率.基于真实网格作业运行记录的实验,验证了所提出方法的有效性和高效性.;A cooperative replica prefetching mechanism is a new replication strategy aiming to reduce the data access latency in grid by the means of replicating implicit high-value files (IHVFs). The key of this new mechanism is the exploration and location of IHVFs. Locating the IHVFs quickly can improve the performance of the mechanism. This paper employs the DHT (distributed hash table) technology to organize grid nodes to quickly locate the file correlation information which is essential for the query of IHVFs. Considering the specific query pattern, a PTree-based storage structure and corresponding query mechanism for file correlation information are proposed to improve the IHVF query efficiency. Simulation results based on real grid workloads have confirmed the effectiveness and high efficiency of the proposed methods.