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| 混合实时事务调度与并发控制研究 | |
| Alternative Title | Mixed Real-Time Transaction Scheduling and Concurrency Control |
| 王强 | |
| Major | 计算机技术应用技术 |
| 2004 | |
| Degree Grantor | 中国科学院软件研究所 |
| Degree Level | 博士 |
| Place of Degree Grantor | 中国科学院软件研究所 |
| Keyword | 实时数据库 混合实时事务 非定期事务 实时事务调度 实时并发控制 反馈控制 截止期错失率 可调度性 |
| English Abstract | 实时数据库系统中，具有不同类型截止期的事务对系统有不同的要求，例如硬实时事务错失截止期会导致很大的系统性能降级甚至灾难性后果，而软实时事务出现少量的截止期错失是可以容忍的。先前的研究大都集中于单个类型实时事务的调度与并发控制，但是混合事务负载的实时一数据库应用需求是非常普遍的。混合实时事务调度的目标是，在保证硬实时事务满足截止期的同时最小化软实时事务的截止期错失率。本文首先深入研究了动态优先级调度算法下硬实时事务的并发控制问题，提出了Hcc-DA（Hard Concurrency Control with Dynamic Adjustment of serialization order）与HCC-EDA（Hard Concurrency Control with Extended Dynamic Adjustability）两种新的并发控制协议。理论分析与仿真测试结果都表明，这两种协议能够改善硬实时事务集的可调度性，并实现更高的处理器利用率。接着，本文给出了一种混合事务调度框架，并在这个框架下提出了一种新的面向混合事务的并发控制协议MCC-DATI（Mixed Concurrency Control with Dynamic Adjustment of serialization order using Timestamp Intervals）；仿真测试结果表明，所提出的协议能够在保证硬实时事务满足截止期的同时降低软实时事务的截止期错失率。进一步，本文把反馈控制的思想应用到混合事务调度框架中，提出了基于反馈控制的混合事务调度（FC-MTS:Feedbock Control Mixed Transoction soheduling）算法；测试结果表明，FC-MTS算法在不影响硬实时事务可调度性的同时能够为软实时事务提供一定的陕能保证。此外，作者设计开发了一个实时数据库仿真测试平台AgilorTP，用于相关算法与协议的性能评估。这个平台提供了充分的可打、一展性与可配置性，支持对新的事务模型、事务调度算法、并发控制协议、实时1／O调度以及缓冲区管理策略的测试与分析。本文的研究成果为进一步探讨混合实时事务的调度与并发控制，以及实际应用中的混合事务处理提供了良好的基础。 |
| Abstract | In real-time database systems, transactions with different types of deadlines have different scheduling requirements. For example, a hard real-time transaction, which misses its deadline, may result in great loss even catastrophe. But it is tolerable for a small quantity of soft real-time transactions to miss their deadlines. Previous study mainly focuses on scheduling and concurrency control on either hard or soft real-time transactions. However, there is an increasing demand in processing mixed transactions in real-time database systems. The system goal with mixed real-time transactions is that the deadlines of hard real-time transactions must be guaranteed, and the number of deadline violations for soft real-time transactions should be minimized. In this paper, two new concurrency control protocols -Hard Concurrency Control with Dynamic Adjustment of serialization order (HCC-DA) and Hard Concurrency Control with Extended Dynamic Adjustability (HCC-EDA), are proposed for hard real-time transactions, which are scheduled under dynamic priority scheduling algorithms. Both theoretic analysis and simulation test show that, these two protocols can improve the schedulability of hard real-time transactions, and achieve higher processor utilization. Next, a framework for mixed transaction scheduling is given, and a new concurrency control protocol - Mixed Concurrency Control with Dynamic Adjustment of serialization order using Timestamp Intervals (MCC-DATI) under the above framework is proposed. The simulation results show that, the proposed protocol can guarantee the deadlines of hard real-time transactions, and reduce the number of deadline violations of soft real-time transactions. Furthermore, a feedback control mixed scheduling algorithm (FC-MTS) is proposed by applying feedback control theory to mixed transaction scheduling framework. The simulation results show that the proposed algorithm can provide some performance guarantee for soft real-time transaction without affecting the schedulability of hard real-time transactions. In addition, a test platform, AgilorTP, is developed for evaluating the performance of proposed algorithms or protocols in real-time databases, which can provide full extendibility and configurability to support the test and analysis of new real-time transaction models, scheduling algorithms, concurrency control protocols, real-time I/O scheduling and buffer management policies. The work in this paper provides the foundation for further research on mixed real-time transaction scheduling and concurrency control, and processing mixed transactions in actual application systems. |
| Pages | 131 |
| Language | 中文 |
| Content Type | 学位论文 |
| URI | http://ir.iscas.ac.cn/handle/311060/6290 |
| Collection | 中科院软件所_中科院软件所 |
| Recommended Citation GB/T 7714 | 王强. 混合实时事务调度与并发控制研究[D]. 中国科学院软件研究所. 中国科学院软件研究所,2004. |
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| LW013918.pdf（1462KB） | 限制开放 | -- | Application Full Text | |||
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