| 摘要: |
| 针对分布式硬实时系统发生处理机故障后,当前周期内的任务实例和后续实例相对截止期限的不同紧迫程度,提出非紧迫周期内延迟策略——DNUP(delay in non-urgent period).该策略能够尽可能地推迟非紧迫实例的执行,使得低优先级实例有更多的机会完成其紧迫周期内的执行,从而实现处理器空闲(slack)资源的合理挪动.仿真实验结果表明,与其他几个著名的分布式容错调度算法相比,DNUP 策略能够提高任务的可调度性,从而有效减少了所需处理机的数目. |
| 关键词: 实时 分布式系统 调度 容错 优先级 |
| DOI：10.3724/SP.J.1001.2012.04004 |
| 分类号: |
| 基金项目:国家自然科学基金(60603032) |
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| Feasible Fault-Tolerant Scheduling Algorithm for Distributed Hard-Real-Time System |
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ZHU Ping1, YANG Fu-Min2, TU Gang2, ZHANG Jie2, ZHOU Zheng-Yong2
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1.College of Mathematics and Computer Science, Wuhan Textile University, Wuhan 430074, China;2.School of Computer Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
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| Abstract: |
| In distributed hard-real-time systems, when a hardware failure occurs, the task instance in current period is usually more urgent than the subsequent ones. According to this, a novel strategy of delay in non-urgent period (referred to as DNUP) is proposed. DNUP strategy can postpone the execution of non-urgent instance as late as possible and reserve the slack time for the instance with low priority. Thus it has a better chance to complete its execution in an urgent period. Extensive simulations reveal that DNUP can improve the schedulability of periodic tasks and achieve a remarkable saving on the number of processors required with respect to several well-known fault-tolerant scheduling algorithms. |
| Key words: real-time distributed system scheduling fault-tolerance priority |
