Dennis Geesen

Odysseus: a highly customizable framework for creating efficient event stream management systems

Odysseus is a flexible, feature-rich and extensible framework to design event stream management systems and was developed to support research in event stream processing. It provides a systematic approach to define sources and queries, execution and presentation of results. Odysseus offers basic functionality for fast deployment, but due to its modular architecture, users can easily configure and expand them to meet a large set of applications and research questions.

Data Stream Management in the AAL: Universal and Flexible Preprocessing of Continuous Sensor Data

Continuous and potentially infinite sequences of data—so-called data streams—are processed in many applications of Ambient Assisted Living (AAL). The preprocessing of such high frequent data is normally done by fixed code or hard wired hardware. This leads on the one hand to an inflexible and extensive to change processing and on the other hand to very specialized solutions. Like databases data stream management systems (DSMS) offer a universal processing of data, but are designed for highly frequent and potentially infinite data streams. Thus, DSMS are an alternative approach for processing sensor data. Therefore, this paper shows how DSMS can be used in the AAL for an universal and flexible preprocessing of sensor data. For this, DSMS and its features are introduced and we show which advantages over existing solutions a DSMS can offer for future researches in AAL.

Scheduling von Datenströmen auf der Basis von Service Level Agreements

ZusammenfassungSoftware as a Service (SaaS) stellt einen Ansatz zur Bereitstellung standardisierbarer Software über das Internet dar. Auch die Verarbeitungskapazität von Datenstrommanagementsystemen (DSMS) kann auf diese Weise verschiedenen Kunden kostengünstig zugänglich gemacht werden. Der Anbieter garantiert dem Kunden eine gewisse Dienstqualität in Form von Service Level Agreements (SLAs), deren Verletzung i.d.R. finanzielle Konsequenzen hat. Der Dienstanbieter ist also zum einen daran interessiert, möglichst geringe Kosten durch die SLA-Verletzung zu verursachen, zum anderen eine optimale Systemressourcenauslastung (CPU, Hauptspeicher, etc.) zu erzielen. Diese Ressourcen werden in DSMS mit Hilfe von Schedulingverfahren den kontinuierlichen Anfragen zugewiesen. In unserer Arbeit haben wir ein aus dem Datenbankkontext stammendes Schedulingverfahren für Datenströme angepasst, das sowohl die durch Verletzungen von SLAs entstehenden Kosten aus Sicht des Anbieters berücksichtigt als auch eine effiziente Ressourcenverteilung ermöglicht. In Simulationen haben wir gezeigt, dass sich durch ein solches Scheduling die Kosten des Anbieters senken lassen.

Demo: Dynamic Generation of Adaptive Real-Time Dashboards for Continuous Data Stream Processing

Conventional database management systems are usually not capable to deal with continuous processing of potentially infinite data streams. Therefore, special data stream management systems and frameworks are developed. They use continuous queries which produce also streams as results, so that static visualization is not feasible, since the results are changing constantly. To handle this, we developed a dashboard concept, which we want to propose in this demonstration. A dashboard can be considered as an control or monitoring panel for real time data stream results. The user is free to define and configure individual dashboard parts. Each part is connected to a (user defined) continuous query, whose results are received and visualized in real-time. In this demonstration, we provide different data stream sources, continuous queries and dashboard parts. With them, the user can compose his own individual presentation of his processing results.