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 literature[1],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.