Auflistung nach Autor:in "Koziolek, Heiko"
1 - 10 von 12
Treffer pro Seite
Sortieroptionen
- KonferenzbeitragAnalysis of the trade-offs in different modeling approaches for performance prediction of software systems(Software Engineering 2016, 2016) Kounev, Samuel; Brosig, Fabian; Meier, Philipp; Becker, Steffen; Koziolek, Anne; Koziolek, Heiko; Rygielski, PiotrA number of performance modeling approaches for predicting the performance of modern software systems and IT infrastructures exist in the literature. Different approaches differ in their modeling expressiveness and accuracy, on the one hand, and their modeling overhead and costs, on the other hand. Considering a representative set of established approaches, we analyze the semantic gaps between them as well as the trade-offs in using them; we further provide guidelines for selecting the right approach suitable for a given scenario.
- KonferenzbeitragArchitecture-based reliability prediction with the Palladio Component Model(Software Engineering 2014, 2014) Brosch, Franz; Koziolek, Heiko; Buhnova, Barbora; Reussner, Ralf
- KonferenzbeitragDynamic Updates of Virtual PLCs deployed as Kubernetes Microservices(Software Engineering 2022, 2022) Koziolek, Heiko; Burger, AndreasIndustrial control systems (e.g. programmable logic control\-lers, PLC or distributed control systems, DCS) cyclically execute control algorithms to automated production processes. Nowadays, for many applications their deployment is moving from dedicated embedded controllers into more flexible container environments, thus becoming ''Virtual PLCs''. It is difficult to update such containerized Virtual PLCs during runtime by switching to a newer instance, which requires transferring internal state. Former research has only proposed dynamic update approaches for single embedded controllers, while other work introduced special Kubernetes (K8s) state replication approaches, which did not support cyclic real-time applications. We propose a dynamic update mechanism for Virtual PLCs deployed as K8s microservices. This approach is based on a purpose-built K8s Operator and allows control application updates without halting the production processes. Our experimental validation shows that the approach can support the internal state transfer of large industrial control applications (100.000 state variables) within only 15 percent of the available cycle slack time. Therefore, the approach creates vast opportunities for updating applications on-the-fly and migrating them between nodes in a cloud-native fashion.
- KonferenzbeitragEmpirische Bewertung von Performanz-Vorhersageverfahren für Software Architekturen(Software Engineering 2005, 2005) Firus, Viktoria; Koziolek, Heiko; Becker, Steffen; Reussner, Ralf; Hasselbring, WilhelmDie Architektur eines Software-Systems beeinflusst maßgeblich seine Qualitätseigenschaften wie Performanz oder Zuverlässigkeit. Daher sind Architekturänderungen oft die einzige Möglichkeit, Mängel bei diesen Qualitätseigenschaften zu beheben. Je später diese Änderungen an der Architektur während des Software-Entwicklungsprozesses vorgenommen werden, desto teurer und riskanter sind sie. Aus diesem Grund ist eine frühzeitige Analyse verschiedener Architektur-Entwurfsalternativen bezüglich ihrer Auswirkungen auf Qualitätseigenschaften vorteilhaft. Dieser Artikel beschreibt die Evaluation dreier verschiedener Performanz-Vorhersageverfahren für Software-Architekturen hinsichtlich ihrer Eignung, korrekte Empfehlungen für frühzeitige Entwurfsentscheidungen zu geben. Zusätzlich sollen diese Vorhersageverfahren prüfen, ob extern vorgegebene Performanz-Anforderungen realisierbar sind. Die Performanz-Vorhersageverfahren SPE“, Capacity Planning“ und „umlPSI“ wurden empirisch durch 31 Teilnehmer untersucht, die eine Menge vorgegebener Alternativen beim Entwurf der Architektur eines Webservers zu bewerten hatten. Die Ergebnisse zeigen, dass Entwurfsalternativen mit allen Verfahren richtig bewertet wurden, sofern deutliche Auswirkungen auf die Performanz vorhanden waren. Ohne den Einsatz der Performanz-Vorhersageverfahren wurden häufiger weniger performante Entwurfsalternativen vorgeschlagen. Darüber hinaus konnte das Verfahren Capacity Planning die absoluten Werte bei den meisten Entwurfsalternativen relativ genau vorhersagen.
- ZeitschriftenartikelErnst Denert Software-Engineering-Preis 2021(Softwaretechnik-Trends Band 42, Heft 2, 2022) Felderer, Michael; Hasselbring, Wilhelm; Koziolek, Heiko; Lilienthal, Carola; Matthes, Florian; Prechelt, Lutz; Reussner, Ralf; Rumpe, Bernhard; Schaefer, InaVorwort zum Ernst Denert Software-Engineering-Preis 2021
- KonferenzbeitragModeling and predicting performance impacts in a service-oriented, industrial software system from the automation domain(Informatik 2009 – Im Focus das Leben, 2009) Koziolek, Heiko; Weiss, Roland; Doppelhamer, Jens
- KonferenzbeitragTool-driven technology transfer to support software architecture decisions(Software Engineering 2014, 2014) Koziolek, Heiko; Goldschmidt, Thomas
- KonferenzbeitragTowards an architectural style for multi-tenant software applications(Software Engineering 2010, 2010) Koziolek, HeikoMulti-tenant software applications serve different organizations from a single instance and help to save development, maintenance, and administration costs. The architectural concepts of these applications and their relation to emerging platform-as- a-service (PaaS) environments are still not well understood, so that it is hard for many developers to design and implement such an application. Existing attempts at a structured documentation of the underlying concepts are either technology-specific or restricted to certain details. We propose documenting the concepts as a new architectural style. This paper initially describes the architectural properties, elements, views, and constraints of this style. We illustrate how the architectural elements are implemented in current PaaS environments, such as Force.com, Windows Azure, and Google App Engine.
- KonferenzbeitragTowards Automatic Construction of Reusable Prediction Models for Component-Based Performance Engineering(Software Engineering 2008, 2008) Kappler, Thomas; Koziolek, Heiko; Krogmann, Klaus; Reussner, RalfPerformance predictions for software architectures can reveal performance bottlenecks and quantitatively support design decisions for different architectural alternatives. As software architects aim at reusing existing software components, their performance properties should be included into performance predictions without the need for manual modelling. However, most prediction approaches do not include au- tomated support for modelling implemented components. Therefore, we propose a new reverse engineering approach, which generates Palladio performance models from Java code. In this paper, we focus on the static analysis of Java code, which we have implemented as an Eclipse plugin called Java2PCM. We evaluated our approach on a larger component-based software architecture, and show that a similar prediction accuracy can be achieved with generated models compared to completely manually specified ones.
- KonferenzbeitragTowards software sustainability guidelines for long-living industrial systems(Software Engineering 2011 – Workshopband, 2011) Koziolek, Heiko; Weiss, Roland; Durdik, Zoya; Stammel, Johannes; Krogmann, KlausLong-living software systems are sustainable if they can be cost-effectively maintained and evolved over their complete life-cycle. Software-intensive systems in the industrial automation domain are typically long-living and cause high evolution costs, because of new customer requirements, technology changes, and failure reports. Many methods for sustainable software development have been proposed in the scientific literature, but most of them are not applied in industrial practice. We identified typical evolution scenarios in the industrial automation domain and conducted an extensive literature search to extract a number of guidelines for sustainable software development based on the methods found in literature. For validation purposes, we map one evolution scenario to these guidelines in this paper.