Efficient constraint monitoring using adaptive thresholds

Detecting constraint violations in large-scale distributed systems has recently attracted plenty of attention from the research community due to its varied applications (security, network monitoring, etc.). Communication efficiency of these systems is a critical concern and determines their practicality. In this paper, we introduce a new set of methods called non-zero slack schemes to implement distributed SUM queries efficiently. We show, both analytically and empirically, that these methods can lead to a considerable reduction in the amount of communication. We propose three adaptive non-zero slack schemes that adapt to changing data distributions; our best scheme is a lightweight reactive scheme that probabilistically adjusts local constraints based on the occurrence of certain events (using only a periodic probability estimation). We conduct an extensive experimental study using real-life and synthetic data sets, and show that our non-zero slack schemes incur significantly less communication overhead compared to the state of the art zero slack scheme (over a 60% savings). © 2008 IEEE.