Trust-Based and QoS Demand Clustering Analysis Customizable Cloud Workflow Scheduling Strategies

Due to the restrictions that most traditional scheduling strategies only care about users´ QoS time or cost requirements, lack the effective analysis of users´ real service demand and cannot guarantee scheduling security, this paper added trust into workflow´s QoS target and proposed a novel customizable cloud workflow scheduling model. In order to better analyze different user´s service requirements and provide customizable services, the new model divides workflow scheduling into two stages: the macro multi-workflow scheduling as the unit of cloud user and the micro single workflow scheduling. It introduced trust mechanism into multi-workflow scheduling level. And in single workflow scheduling level, it classified workflows into time sensitive, cost-sensitive and balance three types according to different workflow´s QoS demand parameters using fuzzy clustering method. Basing on it, it customized different service strategies for different type. The simulation experiments show that the new schema has some advantages in shorteningworkflow´s final completion time, achieving relatively high execution success rate and user satisfaction compared to other kindred solutions.