A XML-based composition event approach as an integration and cooperation middleware

Content-based Pub/Sub systems are gaining increasing popularity as an integration and cooperation middleware supporting large-scale distributed applications, especially for Grid. However, existing content-based Pub/Sub systems mainly focus on the "one-to-one" event matching, not on the composite event matching. The composite event matching enables application components to express more interest in the occurrence of event composite patterns. In this paper, we present a XML-based composite event model that consists of the temporal logical model and the event composite pattern. Based on the composite event model, a subscription language (EXML-QL) is introduced by extending XML-QL to support the XML-based composite event computing. Finally, in terms of the peculiarities of the subscription language, a composite event matching process is presented and analyzed.