多数据流上的连续分布式Top-k监测

近年来，分布式系统中的数据流监测是一个十分活跃的领域。研究了如何实现通用并且高效的分布式top-k监测，即在分布的多数据流中根据用户给定的排序函数连续监测最大的k个值。在实际应用中，用户给定的排序函数可能是任意的排序函数，然而，目前的分布式top-k监测技术只支持加法作为排序函数。提出了一种通用的支持任意的连续的严格单调的聚集函数的分布式top-k监测算法GMR。GMR的通讯代价和k无关。通过真实世界数据和模拟数据验证了GMR的效率。实验表明，GMR的网络通讯量比同类方法低一个数量级以上。

Continuous Distributed Top-k Monitoring over Data Streams

Monitoring data streams in a distributed system is the focus of much research in recent years.This paper addresses the generic and efficient processing of distributed top-k monitoring,which is continuously reporting the k largest values according to a user-specified ranking function over distributed multiple data streams.In practice,the user-specified ranking function would be arbitrary ranking function.Unfortunately,state-of-art distributed top-k monitoring approaches only support the sum function as the ranking function.In this paper,we present a general algorithm GMR for distributed top-k monitoring,which supports arbitrary continuous and strict monotone aggregation functions.The communication cost of GMR is independent of k.We verify the effectiveness of GMR empirically using both real-world and synthetic data sets.We show that GMR reduces overall communication cost by an order of magnitude compared with alternatives.