Deployment strategies for distributed complex event processing

Several complex event processing (CEP) middleware solutions have been proposed in the past. They act by processing primitive events generated by sources, extracting new knowledge in the form of composite events, and delivering them to interested sinks. Event-based applications often involve a large number of sources and sinks, possibly dispersed over a wide geographical area. To better support these scenarios, the CEP middleware can be internally built around several, distributed processors, which cooperate to provide the processing and routing service. This paper introduces and compares different deployment strategies for a CEP middleware, which define (i) how the processing load is distributed over different processors and (ii) how these processors interact to produce the required results and to deliver them to sinks. Our evaluation compares the presented solutions and shows their benefits with respect to a centralized deployment, both in terms of network traffic and in terms of forwarding delay.