数据流QoS自适应框架聚集查询卸载策略的研究  

Research on load shedding for aggregation queries over data streams in the QoS adaptation framework

作　　者：杜钰[1] 韩东红[1] 王国仁[1] 

机构地区：[1]东北大学信息学院,沈阳110004

出　　处：《中国科技论文在线》2007年第10期735-740,共6页

基　　金：国家自然科学基金(60573089;60273079)

摘　　要：本文研究了在数据流QoS自适应框架中,数据流聚集查询的卸载算法问题。在CPU处理能力不足内存超载情况下,在聚集查询操作中对负载进行卸载,并能满足一定的服务质量。对于一个或多个聚集查询存在的情况下,将原有的框架从得到近似结果进一步拓展为可以得到精确结果子集的系统框架。在保留原有清洗器,调度器以及卸载器功能的前提下,进一步改善卸载器的功能,并加入新的如窗口分配器、聚集操作器两个新的功能模块,以确保满足结果是正确结果的子集。本文使用新的卸载算法与原框架相结合,保证系统在执行聚集查询操作时能在动态环境中具有良好的自适应性。实验结果表明,该方法在CPU利用率和错失事优于其它方法。This paper studies the load shedding for aggregation queries over the data streams,which is based on the control-based QoS adaptation framework.In the case of that the CPU capacity is limited and the memory is over loaded,this technique sheds load from memory in aggregation operation,meanwhile,promising a proper QoS.As there is a single aggregation or several aggregation operations,this technique extends the existed framework to an advanced one which can get the subset of the accurate result instead of getting the approximate ones.It keeps the original components such as the cleaner,scheduler and the load shedder,but also extends the load shedder part. Further,adding new components called window-distributor and aggregate-operator to the frame,to promise the accurateness of the result.It combines the new strategy to the existed frame to make sure that the system can be adaptive in dynamic environments when processing the aggregation queries.The experiments show that the system is outperforms other existing ways on resource utilization and deadline miss ratio.

关 键 词：计算机系统结构 数据流管理系统 聚集 卸载 服务质量 

分 类 号：TP311.13[自动化与计算机技术—计算机软件与理论]