Monitoring of Composite Events in Distributed Systems

Large and highly concurrent systems tend to generate large numbers of events which require further processing, such as filtering and establishment of co-relations, in order to become useful for human or automated managers. This work focuses on the detection of composite events defined through event expressions involving primitive events and some operators: boolean conjunction and disjunction; sequence, repetition, and absolute, periodic and relative timer events.

A concrete result of this work was the design and implementation of a general-purpose Event Processing Service (EPS) which may be used by monitoring applications to be informed about the occurrence of primitive and composite events. Composite events are commonly represented as trees where the leaf nodes represent primitive event types and the intermediate nodes represent any of the supported event operators. The main contribution of this work is the description of a method to process composite events that share common sub-expressions with other composite events.

The Event Processing Service was implemented in Java within the framework of the Sampa Project.

Download the Event Processing Service

Last modified: Wed Apr 19 08:06:51 BRT 2000