Moving range queries in distributed complex event processing

Abstract

Up to now, correlations in complex event processing (CEP) systems are detected by a well defined set of operators, whose configuration is determined ahead of deployment time. Although CEP operators involve location specific attributes, state of the art systems are heavily constrained in detecting situations where the interest in a situation changes depending on the consumer's location, e. g., with the movement of mobile devices. This paper adopts the concept of range queries to CEP systems. We propose a mobility-aware event delivery semantics and present a corresponding execution model, which accounts for mobility driven selection of primary event streams to the CEP system. By utilizing the properties of this execution model, we derive an algorithm that establishes low cost and coordinated reconfiguration of CEP operators in a distributed system. The algorithm minimizes the amount of information that needs to be streamed between operators and avoids additional delays as a result of a reconfiguration of CEP operators. We present an analysis of the algorithm's properties and evaluate the efficiency of the proposed reconfiguration algorithm.