摘要
并行任务调度是影响机群计算效率的关键因素之一,机群环境DAG(DirectedAcyclicGraph)任务图调度是一个NP完全问题,只能寻求启发式算法。已有的研究中,图解重构算法在允许任务复制的条件下,通过对DAG图递归分解与子图重构,初步实现了一个可行的调度方案。该文在此基础上,提出了以调度长度增量为依据的任务复制策略,利用该策略调整受制约节点的同簇前驱,解决了任务簇间的时间制约问题,缩短了调度长度;通过合理地选择任务簇进行合并,增大任务簇的粒度,提高了处理器的利用率。提出的以任务簇扩展-合并为特征、以分簇复制为手段的DAG图调度算法,改进和拓展了图解重构方法。实例分析表明本算法复杂度与TDS(TaskDuplicationScheduling)相同,但性能更优。
Parallel task scheduling is one of the key factors influencing the efficiency of clusters, and it is also a well-known strong NP-hard problem. Zhou and Zheng have proposed a task duplication based algorithm, which adopts recursion to implement DAG partition and sub-graph reconfiguration, then builds task clusters to carry out scheduling. This paper further exploits their method and proposes a task duplication strategy emphasizing the increment of scheduling length. Using this strategy, the restriction problem between clusters is effectively solved by adjusting the predecessors of the restricted task in the same cluster; besides, appropriate task clusters are selected and merged, leading to coarse-grained clusters and better processor utilization. Furthermore, a DAG scheduling algorithm based on task clustering and duplication is presented in this paper, which is characterized by expanding and merging clusters, and has advantages in both scheduling length and processor utilization over the original algorithm. Experiment results show that the algorithm has the same complexity with TDS （task duplication scheduling） and achieves better performance.
出处
《计算机工程》
EI
CAS
CSCD
北大核心
2006年第17期126-128,134,共4页
Computer Engineering
基金
国家自然科学基金资助项目(60173026)
教育部科研基金资助重点项目(105071)
上海高校网格技术E-研究院资助项目(200301-1)
关键词
机群计算
任务图
任务调度
分簇复制
Cluster computing
Task graph
Task scheduling
Clustering and duplication
作者简介
乔伟光（1982-），男，硕士生，主研方向：网格计算；E-mail：r_qwg@sina．com
曾国荪，博士、教授、博导。
