QoS Constraint Based Workflow Scheduling for Cloud Computing Services
Guangzhen Lu, Wenan Tan, Yong Sun, Zijian Zhang, Anqiong Tang · Journal of Software · 2014
Abstract—QoS constraint based workflow scheduling described by Directed Acyclic Graph (DAG) has been proved to be a NP-hard problem in Cloud Computing Services, especially for cost minimization under deadline constraint. Due to Deadline Bottom Level (DBL) hasn’t considered the concurrence during the real executing process that cause much more shatter time to solve such problem, this paper proposes a novel heuristics approach of Concurrent Level based Workflow Scheduling (CLWS). It stratifies all the tasks according to the concurrence among tasks in the actual workflow execution. Then, CLWS distributes the total redundancy time into every level according to their concurrent degree. The simulation experiments show that CLWS makes a better improvement than DBL. Index Terms—workflow scheduling, cost/time tradeoff, heuristics, concurrent level I.