Deadline-constrained cost-aware workflow scheduling in hybrid cloud

Abstract

Cloud computing offers resources to users for computing and storage needs on the policy pay-what-you-use model. A private cloud is an excellent cost-saving option because the user owns the resources and can be used free to execute workflow applications. However, when private cloud resources are insufficient to fulfill the needs of workflow applications, the public cloud is the only option. To this end, a hybrid cloud (HC) is an elegant way to combine public and private cloud resources to meet the requirements of workflow applications. Therefore, large enterprises prefer the HC, but task scheduling in the HC is complicated. Therefore, this study proposed a Deadline-constrained Cost-aware Workflow Scheduling (DCWS) algorithm to address task scheduling problems in the HC. Firstly, we will execute maximum workflow tasks on the private cloud owned by users under the deadline constraint. Secondly, send the unscheduled workflow tasks to the public cloud for execution. Lastly, we will ensure scheduling whole workflow tasks on the private cloud and the communication channels (for sending to the public cloud) to satisfy the task-precedence needs and the task deadline constraint while incurring a minimal monetary cost. Furthermore, we reduce task slack time with the help of the sub-deadline division technique and search for an ideal virtual machine (VM) to reduce further execution time and monetary cost. The experimental results prove that the DCWS algorithm outperformed existing algorithms.