The Jadex Event Stream Processing Architecture (JESPA) is an agent-based middleware specifically designed to detect and process complex events within streams of primitive events. Such primitive events may originate from RFID systems or any other kind of physical or virtual sensor or sensor network, and usually contain raw sensor measurements, such as an EPC read by an RFID reader. In order to detect complex relationships between multiple primitive events, possibly spanning different event streams, complex event-processing techniques are applied. For this purpose, our middleware incorporates a high-performance, open source event-processing engine (Esper), which allows to define complex event patterns using an SQL-like event-processing language. Moreover, our middleware allows to individually pre-process the incoming events before they are forwarded to the complex event-processing engine, and to postprocess the resulting generated complex events. For this purpose, a multitude of standard services (e.g., classification, persistence, enrichment) are offered by the middleware, and may be complemented by a producer or consumer injecting additional user-defined services. For the orchestration of services within the middleware, executable BPMN-based processing workflows are used. An example of such postprocessing is the escalation handling, during which arbitrary service agents may be invoked in order to react on undesired conditions. The post-processing stage may also be used to create individually tailored application-level events, which only contain relevant information in a desired format, by invoking conversion, translation, and encoding services. The results can then directly be further processed by enterprise systems, such as supply-chain management and workflow-management systems, intelligent objects, or web-based services. This way, event producers (RFID/sensor readers) and event consumers (like enterprise systems) do not need to adapt their business logic to the middleware's functionality and data formats, but may abstract from how events are generated and how actions are carried out, benefiting from the middleware's ability to conduct the overall processing.

Publications of Project JESPA

Steffen Kunz, Benjamin Fabian, Holger Ziekow, Dirk Bade From Smart Objects to Smarter Workflows – An Architectural Approach in: Enterprise Distributed Object Computing Conference Workshops (EDOCW), Helsinki