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Auflistung nach Autor:in "Krause, Alexander"

1 - 5 von 5
  • Konferenzbeitrag
    Hierarchical software landscape visualization for system comprehension: A controlled experiment
    (Software Engineering 2016, 2016) Fittkau, Florian; Krause, Alexander; Hasselbring, Wilhelm
    An efficient and effective way to comprehend large software landscapes is required. The current state of the art often visualizes software landscapes via flat graph-based representations of nodes, applications, and their communication. In our ExplorViz visualization, we introduce hierarchical abstractions aiming at solving typical system comprehension tasks fast and accurately for large software landscapes. To evaluate our hierarchical approach, we conduct a controlled experiment comparing our hierarchical landscape visualization to a flat, state-of-the-art visualization. In addition, we thoroughly analyze the strategies employed by the participants and provide a package containing all our experimental data to facilitate the verifiability, reproducibility, and further extensibility of our results. We observed a statistically significant increase in task correctness of the hierarchical visualization group compared to the flat visualization group in our experiment. The time spent on the system comprehension tasks did not show any significant differences. The results backup our claim that our hierarchical concept enhances the current state of the art in landscape visualization for better software system comprehension. While program comprehension has been researched extensively, system comprehension has received much less attention. From a historical point of view, program comprehension became important when programs reached more than a few hundreds lines of code. Today's IT infrastructures in enterprises often consist of several hundreds of applications forming large software landscapes [FRH15]. Our ExplorViz approach [FWWH13] provides live visualization for large software landscapes introducing three hierarchical abstractions [FRH15]. Life visualization with Ex- plorViz is scalable [FH15] and elastic in cloud environments [vHRGH09]. We present a controlled experiment to compare a flat, state-of-the-art landscape visualization to our hierarchical visualization in the context of system comprehension [FKH15c]. Additional features of ExplorViz include trace visualizations [FFHW15], architecture conformance checks [FSH14], and a landscape control center [FvHH14] with performance anomaly detection [EvHWH11, MRvHH09]. New perspectives on employing virtual reality [FKH15b] and physical models [FKH15a] are further explored. Beneath evaluating if a hierarchical visualization provides benefits, we conducted this experiment to get input for improving our ExplorViz tool.
  • Textdokument
    NeMeSys – Energy Adaptive Graph Pattern Matching on NUMA-based Multiprocessor Systems
    (BTW 2019, 2019) Krause, Alexander; Ungethüm, Annett; Kissinger, Thomas; Habich, Dirk; Lehner, Wolfgang
    NeMeSys is a NUMA-aware graph pattern processing engine, which leverages intelligent resource management for energy adaptive processing. With modern server systems incorporating an increasing amount of main memory, we can store graphs and compute analytical graph algorithms like graph pattern matching completely in-memory. Such server systems usually contain several powerful multiprocessors, which come with a high demand for energy. We demonstrate, that graph patterns can be processed in given performance constraints while saving energy, which would be wasted without proper controlling.
  • Konferenzbeitrag
    Path Expressions Revisited
    (Tagungsband des FG-BS Herbsttreffens 2024, 2024) Hövelmann, Thomas Alexander; Krause, Alexander; Ulbrich, Peter
    Path expressions provide a precise and concise method for defining synchronization rules for accessing shared data. In conjunction with predicates, even finer control of the sequences can be achieved. Furthermore, path expressions, with their ability to abstract from a specific synchronization technique, demonstrate a high level of adaptability. Despite being developed nearly five decades ago, they remain underrepresented in current software engineering and have yet to achieve widespread applicability. This paper reevaluates existing approaches and presents an automaton-based version of path expressions written in C++. We extend the concept of predicates to allow access to external system states and evaluate the feasibility and performance of our approach.
  • Konferenzbeitrag
    Simplifying Software System Monitoring through Application Discovery with ExplorViz
    (Softwaretechnik-Trends Band 39, Heft 3, 2019) Krause, Alexander; Zirkelbach, Christian; Hasselbring, Wilhelm
    Keeping an overview of software systems is a crucial task in the area of software engineering. Often this task is supported by application performance management (APM) tools, e.g., Kieker, a monitoring framework based on dynamic software analysis. Kieker is highly extensible and customizable, but lacks a user-friendly setup configuration due to its framework characteristic. Based on this obstacle, users of our live trace visualization tool ExplorViz, which employs Kieker, experience problems during monitoring their applications. In this paper, we report on our ExplorViz application discovery and monitoring management system (ADAMMS) to circumvent this drawback. The key concept is to utilize a software agent that simplifies the discovery of running applications within operating systems. Furthermore, the ADAMMS properly configures and manages Kieker instances to monitor these applications. Thereupon, we demonstrate how the monitoring procedure can be eased and how both open source projects ExplorViz and Kieker mutually benefit from our approach. Finally, we conduct a first pilot study to evaluate the usability of our approach with respect to an easy-to-use application monitoring.
  • Konferenzbeitrag
    Working with Disaggregated Systems. What are the Challenges and Opportunities of RDMA and CXL?
    (BTW 2023, 2023) Geyer, Andreas; Ritter, Daniel; Lee, Dong Hun; Ahn, Minseon; Pietrzyk, Johannes; Krause, Alexander; Habich, Dirk; Lehner, Wolfgang
    The usage of disaggregated systems in large scale data-centers offers a lot of flexibility and easy scalability in comparison to the traditional statically configured scale-up and scaleout systems. Disaggregated architectures allow for the creation of software composable systems in order to create a virtual machine by software out of the pool of available hardware resources. In this paper, we propose a memory disaggregation classification and applicable use cases. We would be delighted to present our ideas and the memory disaggregation classification at the workshop and discuss the presented ideas. The valuable feedback of the attendees will help us to further refine our classification both in terms of preciseness and applicability.