Score Based Deadline Constrained Workflow Scheduling Algorithm for Cloud Systems

Cloud Computing is the latest and emerging trend in information technology domain. It offers utilitybased IT services to user over the Internet. Workflow scheduling is one of the major problems in cloud systems. A good scheduling algorithm must minimize the execution time and cost of workflow application along with QoS requirements of the user. In this paper we consider deadline as the major constraint and propose a score based deadline constrained workflow scheduling algorithm that executes workflow within manageable cost while meeting user defined deadline constraint. The algorithm uses the concept of score which represents the capabilities of hardware resources. This score value is used while allocating resources to various tasks of workflow application. The algorithm allocates those resources to workflow application which are reliable and reduce the execution cost and complete the workflow application within user specified deadline. The experimental results show that score based algorithm exhibits less execution time and also reduces the failure rate of workflow application within manageable cost. All the simulations have been done using CloudSim toolkit.