基于多QoS目标的工作流任务调度算法

根据工作流任务的结构特点对其进行分区，按照任务量和通信量将总工作流截止日期和总工作流花费分为每个任务分区上的子截止日期和子花费，在考虑用户多个QoS要求及工作流任务间通信时间的基础上，提出基于信任与花费的综合效益函数，给出信任与花费权值的确定方法以及一个以综合效益最优为目标的调度算法——TCD，算法通过追求局部最优达到全局多目标优化调度。与其他算法的比较表明，该算法服务拒绝率最多可降低15%，能较好地满足用户多QoS要求。

Workflow Task Scheduling Algorithm Based on Multi-QoS Objective

Workflow tasks are partitioned according to the characteristic of workflow tasks structure, and the whole deadline and cost are divided into sub-deadline and sub-cost in every task partition by task length and traffic between tasks. Based on the users’ multi-QoS requirements and communication time between workflow tasks, this paper presents a trust-and-cost-based comprehensive beneficial function, a strategy of determination of trust’s and cost’s weight, and a scheduling algorithm——TCD which takes trust and cost comprehensive optimization as its objective. The multiple objective optimal scheduling of the whole is reached by pursuing part optimization. Compared with others algorithms through simulation shows that the service refuse rate of the algorithm can reduce by 15% at most and it satisfies users’ multi-QoS well.