云工作流中基于分时虚拟机的任务层调度算法

云计算是新的一种面向市场的商业计算模式,向用户按需提供服务,云计算的商业特性使其关注向用户提供服务的服务质量。任务调度和资源分配是云计算中两个关键的技术,所使用的虚拟化技术使得其资源分配和任务调度有别于以往的并行分布式计算。目前主要的调度算法是借鉴网格环境下的调度策略,研究基于QoS的调度算法,存在执行效率较低的问题。我们对云工作流任务层调度进行深入研究,分析由底层资源虚拟化形成的虚拟机的特性,结合工作流任务的各类QoS约束,提出了基于虚拟机分时特性的任务层ACS调度算法。经过试验,我们提出的算法相比于文献1]中的算法在对于较多并行任务的执行上存在较大的优势,能够很好的利用虚拟的分时特性,优化任务到虚拟机的调度。

Virtual Machine-Time-sharing Based Task-level Scheduling Algorithm in Cloud Workflow

Cloud computing is a new market-oriented business model,providing the users the services they need,so that the commercial characteristics of cloud computing makes service providers pay more attention to the quality of service users need.Task scheduling and resource allocation are two key cloud technologies,and virtualization technology makes its resource allocation and task scheduling is different from the previous Parallel distributed computing.Currently,The scheduling algorithm in Cloud Workflow references to the scheduling strategy in grid environment.Based QoS scheduling algorithm in some papers are Inefficient in Cloud Environment.In this paper,they focus on Task-level scheduling in Cloud Workflow and analysis the features of virtual machines which is from the underlying resource by virtualization,.considering all kinds of QoS constraints of workflow tasks,they propose ACS scheduling algorithm based on virtual machine sharing features.By the simulation experiment,the proposed algorithm,compared to the algorithm in the literature1],shows the better performance in the situation where there are many parallel tasks,and can make good use of virtual resource and optimize the Task-to-VM assignment in the cloud data centers.