Associate Task Scheduling Algorithm Based on Delay-Bound Constraint in Cloud Computing

Task scheduling is one of the most important issues in the cloud computing environments. In the cloud systems, the main goal of the task scheduling algorithms is to balance the workload among the computing nodes and maximize the utilization while meeting the bound of the total execution time. Concerning the delay of the associated tasks scheduling in cloud computing, a hierarchical task model was discussed and the associated task scheduling algorithm based on delay-bound constraint (ATS-DB) was proposed. The associated tasks and the task execution order were represented by one directed acyclic graph (DAG). The proposed hierarchical task model can improve the task execution concurrency. The independent tasks in each layer was grouped into the corresponding task set belonging to the task layer. Through the calculation of the total tasks execution time bound in each task layer, the associated task was dispatched to the resources with the minimum execution time. Extensive experimental results demonstrated that the proposed ATS-DB algorithm can achieve better performance than HEFT algorithm in the terms of the total execution time and resource utilization.