摘要
I/O突发是造成I/O瓶颈的一个主要原因,研究I/O负载中普遍存在的突发性并对负载进行精确合成,对存储系统设计及其性能评价具有重要意义。对实际I/O负载的研究表明,传统的泊松假定难以准确地描述长时间范围内的I/O突发行为。研究发现,I/O突发在不同时间尺度下具有相似性,即I/O负载具有自相似性,因此,自相似模型被用来刻画I/O负载中的长相关性。针对I/O负载自相似参数估计,总结了各种常用的时域和频域估值方法。着重对已有的I/O负载合成模型进行了剖析,讨论了各种自相似模型、多分形模型以及alpha稳定模型的特点。探讨了有待解决的开放性问题,并对I/O负载自相似性研究的发展趋势进行了展望。上述工作将对存储负载的自相似性研究提供有益参考。
I/O bursty is one of the main reasons causing I/O bottleneck, so, it is significant for designing storage system and evaluating system performance to study and accurately synthesize the ubiquitous bursty in I/O workload. Research results show that the traditional poisson assumption is difficult to describe the I/O-burstiness behavior well at the long- term time scales, and I/O bursty exhibits the similarity at different time scales, i. e. , self-similarity. So, self-similar mo- dels are used to characterize the long-range dependence in I/O workloads. Aimed at the Hurst parameter estimate, this paper summarized the time-domain and frequency-domain estimators usually used to estimate the degree of self-similarity in storage workloads. After that, some existing models synthesizing I/O workloads were examined, thereinto, the char aeteristies of self-similar,multi-fractal and alpha-stable models were discussed. After summarizing the unresolved prob- lems, this paper explored the future trend of the study on self-similarity in I/O workloads. The above work will provide a valuable reference for pushing the research on self-similarity in storage workloads.
出处
《计算机科学》
CSCD
北大核心
2013年第3期24-30,共7页
Computer Science
基金
国家科技支撑计划资助项目(2012BAD35B08)
中央高校基本科研业务费专项资金资助项目(XDJK2012A006)
重庆市自然科学基金项目(2011BB2008)
西南大学博士基金资助项目(SWU111015)资助
关键词
存储系统
I
O负载
自相似性
Storage system, I/O workload, Self-similarity
