Scheduling Of Cloud Workflow On Budget And Deadline Constraints

With the rapid growth of information,the meticulous division of labor and complex data processing in scientific research,work and daily life make workflow technology widely used.While cloud computing technology can provide high performance computing resources,it makes more and more workflow applications executed in the cloud,such as scientific computing,multi-layer Web and large data processing applications.Cloud computing is the development of traditional distributed computing such as grid and cluster.Cloud services is a dynamic business service model,it uses the virtualization technology provide the Internet users flexible cloud computing resources.However,due to the new characteristics of cloud computing,the scheduling problem of workflow application in cloud environment has become an important research topic.The challenges are the NP-hard nature of the task resource mapping;the user's different QoS requirements;on-demand resource allocation;performance fluctuations and fault handling;mixed resource scheduling;data storage and transport optimization.Many of the existing workflow scheduling algorithms are based on the original scheduling strategy in the grid environment.Therefore they cannot meet the current scheduling objectives.The main contributions of this work include four aspects:First,this paper studies the workflow scheduling strategy in the cloud environment,introduces the existing workflow scheduling algorithms,and focuses on the low complexity list scheduling algorithm,and analyzes the algorithms used in the cloud environment scheduling Workflows on Budget and Deadline Constraints.Second,this paper proposes the workflow scheduling model in cloud environment,makes mathematical modeling and description of cloud workflow application,cloud resource and scheduling respectively,and describes the deadline and budget constraints of workflow scheduling process.Third,in order to solve the problem that the scheduling success rate is not good while scheduling the workflow on deadline and budget constraints in the cloud environment,we propose a scheduling algorithm based on path weights to meet both the deadline and the budget requirements.Unlike other algorithms,this paper considers the instability of the performance in the cloud environment,and proposes the dynamic scheduling strategy in the process of workflow execution.Last,the PWHEFT algorithm and the dynamic scheduling strategy are added to the cloud computing simulation platform CloudSim.By simulating five real workflow applications,generating the DAG instance according to the communication calculation and other parameters,and adding extended class,the platform can support the simulation of workflow scheduling in cloud environment.The simulation program of workflow scheduling is implemented on the extended platform.The simulation and comparison of the proposed two algorithms are carried out.The experimental results show that the two algorithms have better performance when scheduling these cloud workflows.