关键词: 分布式系统, 阈值监控, 连续查询, 通信开销

Abstract: The problem of communication reduction over continuous threshold monitoring in distributed systems is considered in this paper.A Communication Efficient Method（CEM） is proposed which utilizes the relationship among objects and processes them as a whole，therefore achieves better performance than those who holding each object separately.In specific，the object with largest value is chosen as the representative object，and adjustment factors are used to guarantee that local value of representative object is also the largest one in each remote node.Therefore，only the representative object needs to be monitored continuously as long as all the local constrains are valid.When local constrain is violated，communication is needed among the coordinator and remote nodes to rebuild the constrain.Experimental evaluation on real data sets show the efficiency of CEM on communication reduction over distributed threshold monitoring.

Key words: distributed system, threshold monitoring, continuous query, communication reduction