【摘要】 针对广域网高延迟、低带宽的特性给广域文件系统访问带来的性能影响问题,提出了一种不依赖于底层文件系统、能够加速广域文件系统读写访问的缓存策略.该策略支持基于区间粒度的文件数据缓存及访问,并支持元数据本地缓存;该策略提供基于阈值的容量管理功能,采用超时与最终一致相结合的方式维护缓存的一致性.最后使用典型的文件I/O基准测试工具和元数据性能测试工具对该缓存策略进行了评测,实验结果表明:该缓存策略减少了客户端与服务器的交互次数,给广域文件系统的数据访问带来了明显的性能提升,当缓存命中时其数据的读写性能与本地文件系统相近.更多还原

【Abstract】 To address the performance issues over high latency,low bandwidth wide-area links,we propose a caching strategy which is independent of the underlying local file systemsand can speed up data access in wide-area file systems.In our approach,files are cached and accessed at the granularity ofextents and can be eliminated on a threshold-based policy;metadata is also cached locally.With regard to consistency model,it is achieved based ontimeout and eventual consistency.We use file I/O benchmark and metadata benchmark programs to validate our approach.Evaluation results demonstrate that our approach reduces interactions between client and server,therefore dramatically increases the overall performance of data access in wide-area environment.The tests also show that if there is a cache hit,it can offer a comparable performance to local file systems.更多还原