嵌套事务模型下实时数据库故障处理策略  

Failure processing strategy for real-time database systems based on the nested transaction model

作　　者：肖迎元[1,2] 张德干[1,2] 刘云生[3] 

机构地区：[1]天津理工大学计算机科学与技术学院,天津300191 [2]天津市智能计算及软件新技术重点实验室,天津300191 [3]华中科技大学计算机科学与技术学院,湖北武汉430074

出　　处：《计算机集成制造系统》2009年第1期173-178,183,共7页Computer Integrated Manufacturing Systems

基　　金：国家863计划资助项目(2007AA01Z188);国家自然科学基金资助项目(60773073);天津市自然科学基金资助项目(08JCYBJC12400)~~

摘　　要：针对嵌套事务的特性,提出了一种新的、支持嵌套实时事务模型的故障恢复模式。该故障恢复模式改进了传统的日志记录类型与结构,能更好地适应嵌套事务的特性与时态数据的时限需求。在日志缓冲区分配策略上,并发的嵌套实时事务被分配在独立的活动日志区,解决了顺序日志模式中当前日志缓冲页因为严重的访问竞争而影响系统性能的问题。在故障发生后的恢复处理算法中,对重做起始点选择与执行顺序进行了优化处理,在确保提交事务持久性的前提下,尽可能地提高恢复性能。性能测试显示,该恢复模式具有比传统恢复模式更好的性能。Aiming at the characteristics of nested transactions, a novel failure recovery mode supporting the nested real-time transaction model was presented. Compared to the traditional recovery mode, log record type and structure were improved in the proposed recovery mode to better adapt to the characteristics of nested transactions and the timing constraint requirement of temporal data. On the allocation policy of log buffer, concurrent nested real-time transactions were allocated to independent active log areas, therefore the performance bottleneck caused by severe contention for the current log buffer page in the sequential log mode was solved. On the basis of guaranteeing the continuity of committed transactions, the recovery processing algorithm after failures was optimized by selecting starting point and execution sequence of Redo to enhance the recovery performance to the largest extent. Performance test showed that the proposed recovery mode had better real-time performance than the traditional one.

关 键 词：数据库系统 嵌套事务 故障恢复 日志模式 

分 类 号：TP311[自动化与计算机技术—计算机软件与理论]