http://dl.gi.de/handle/20.500.12116/6251 Beiträge im Fachbereich Betriebssysteme, Kommunikationssysteme und Verteilte Systeme (SYS) 2026-07-21T14:05:54Z http://dl.gi.de/handle/20.500.12116/40507 Towards a Cloud Service for State-Machine Replication Heß, Alexander; Hauck, Franz J. State-machine replication (SMR) is a well-known technique to achieve fault tolerance for services that require high availability and fast recovery times. While the concept of SMR has been extensively investigated, there are still missing building blocks to provide a generic offer, which automatically serves applications with SMR technology in the cloud. In this work, we introduce a cloud service architecture that enables automatic deployment of service applications based on customer-friendly service parameters, which are mapped onto an internal configuration that comprises the number of replicas, tolerable failures, and the consensus algorithm, amongst other aspects, The deployed service configuration is masked to large extent with the use of threshold signatures. As a consequence, a reconfiguration in the cloud deployment does not affect the client-side code. We conclude the paper by discussing open engineering questions that need to be addressed in order to provide a productive cloud offer. 2023-01-01T00:00:00Z http://dl.gi.de/handle/20.500.12116/40506 Using Genode OS for Remotely Updated Embedded IoT Devices Matthé, Maximilian; Kühne, Paul; Schlatow, Johannes This paper demonstrates the usage of the Genode OS for wirelessly connected, embedded IoT devices. We show that the modular Genode OS makes the system robust against corrupted or erroneous updates and provides builtin rollback functionality. It enables an increased uptime of the device compared to using an embedded Linux OS. We compare the performance of such device against an embedded Linux. The claimed properties are presented in the form of a demonstrator which can initiate discussions among experts from academia and industry. 2023-01-01T00:00:00Z http://dl.gi.de/handle/20.500.12116/38506 Performance is not Boolean: Supporting Scalar Configuration Variables in NFP Models Friesel, Daniel; Spinczyk, Olaf Non-functional properties (NFPs) such as memory requirements, timing, or energy consumption are important characteristics of embedded software systems and software product lines (SPLs) in general. Both during system design and at runtime, the goal is to optimize resource utilization (and, thus, NFPs) by appropriate system configuration or orchestration. NFP models, learned from benchmarks of various SPL configurations, allow for the prediction of these properties, thus enabling NFP-aware software configuration and runtime decisions. However, many existing approaches for automated learning of NFP models limit their scope to boolean variables. We argue that this is no longer sufficient: NFP models must accommodate scalar variables to achieve suitable accuracy when faced with today’s highly configurable software systems and variable workloads. To this end, we evaluate four regression tree-based NFP modeling approaches on eight use cases, and examine model complexity and model accuracy. We find that models with support for scalar variables achieve up to three times lower mean model error when predicting configurations that were not part of the training set. At the same time, the complexity of scalar and boolean-only models is nearly the same; only benchmarking becomes more time-intensive due to the need to explore scalar variables. We conclude that scalar-enabled models provide increased accuracy almost free of charge, and recommend using them when generating NFP models for embedded systems and workloads with scalar configuration variables. 2022-01-01T00:00:00Z http://dl.gi.de/handle/20.500.12116/38504 SmartOS: An OS Architecture for Sustainable Embedded Systems Scheipel, Tobias; Batista Ribeiro, Leandro; Sagaster, Tim; Baunach, Marcel The number of embedded devices is growing, and so are the concerns about dependability and sustainability. However, the life-span of modern devices is commonly very short, due to their lack of long-term maintainability in both hardware and software. This yields an increased amount of e-waste, as the individual devices are commonly very cheap and can therefore easily be replaced in case of (partial) obsolescence. In this work, we show an operating system architecture which is designed to make embedded systems more sustainable and prepared for long-term use. To do so, we implement a general basic architecture alongside extended concepts and special features within the operating system. Our approach is based on hardware/software co-design and the opportunity to update software as well as hardware in a modular way at runtime. Therefore, logic reconfiguration of the host platform, dynamic software composition and integration, as well as formal methods for verification and portability are supported. 2022-01-01T00:00:00Z