A QoS-based scheduling algorithm for instance-intensive workflows in cloud environment

Along with the rapid development of the Internet, especially the advent of cloud computing era, instance-intensive workflow applications will play an increasingly important role in people's daily life. Most of the existing scheduling algorithms are designed just for a single complex workflow instance. This paper takes cloud workflow as a research background, completely generalizes and describes the instance-intensive workflow scheduling optimization problems based on QoS (Quality of Service) under the current architecture of cloud workflows. Then this paper classifies workflow tasks based on user's QoS preference, and combines with staggered sub-deadlines allocation criteria, proposes a QDA scheduling algorithm suitable for instance-intensive workflows in cloud environment. Simulation results show that, compared to other algorithms, QDA algorithm can better meets the different requirements from users, and also has a much better load balancing rate.