可变负载动态反馈弹性调度模型及其算法研究

由于工作负载的动态变化,以多媒体应用为代表的软实时系统的运行具有很大的不确定性.在这种情况下,依靠任务的静态属性进行调度分析和决策不足以为系统提供高效、实用的资源分配支持.提出一种弹性资源调度算法,该算法周期地采集系统的作业总数和作业丢失数,并以此为根据改变部分软实时任务的作业周期,以调整系统在下一个采样周期内的作业总数,达到满足任务的QoS(quality of service)、接纳尽可能多的服务请求、提高系统的并发服务能力的目的.详细分析了模型结构和核心算法的实现机制,并利用模拟平台对该算法进行了验证.实验结果表明,该算法在提高资源利用效率的同时,还具有良好的稳定性和收敛性.

Research on Dynamic Feedback and Elastic Scheduling Model and Algorithm for Flexible Workload

Due to the variation of the tasks attributes, the behavior of soft real-time systems, such as multimedia application, is becoming increasingly unpredictable. Under this circumstance, the scheduling algorithms, which depend on the tasks static attributes, cant give a usable and efficient resource allocation to those soft real-time systems. This paper presents an elastic scheduling algorithm for flexible workload. Based on sampling the total number and lost number of the task instances, this algorithm adjusts the number of task instances executing in the next sampling period to guarantee the tasks basic QoS (quality of service) and to improve the system resource utilization and concurrency in the next sampling period. This paper analyzes the model and evaluates its performance. Simulation results show that, besides improving resource utilization, this algorithm has good stability and convergence.