RACED: an adaptive middleware for complex event detection

While several event notification systems are built around a publish-subscribe communication infrastructure, the latter only supports detection of simple events. Complex events, involving several, related events, cannot be detected. To overcome this limitation, we designed RACED, an adaptive middleware, which extends the content-based publish-subscribe paradigm to provide a complex event detection service for large scale scenarios. In this paper we describe its main aspects: the event definition language; the protocol enabling efficient and distributed detection of complex events through a network of service brokers; the mechanism that enables RACED to dynamically adapt to network traffic. A preliminary evaluation shows the benefits of RACED w.r.t. more traditional publish-subscribe infrastructures.