| 1. |
- Scheuner, Joel, 1991, et al.
(author)
-
CrossFit: Fine-grained Benchmarking of Serverless Application Performance across Cloud Providers
- 2022
-
In: Proceedings - 2022 IEEE/ACM 15th International Conference on Utility and Cloud Computing, UCC 2022. ; , s. 51-60
-
Conference paper (peer-reviewed)abstract
- Serverless computing emerged as a promising cloud computing paradigm for deploying cloud-native applications but raises new performance challenges. Existing performance evaluation studies focus on micro-benchmarking to measure an individual aspect of serverless functions, such as CPU speed, but lack an in-depth analysis of differences in application performance across cloud providers. This paper presents CrossFit, an approach for detailed and fair cross-provider performance benchmarking of serverless applications based on a providerindependent tracing model. Our case study demonstrates how detailed distributed tracing enables drill-down analysis to explain performance differences between two leading cloud providers, AWS and Azure. The results for an asynchronous application show that trigger time contributes most delay to the end-to-end latency and explains the main performance difference between cloud providers. Our results further reveal how increasing and bursty workloads affect performance stability, median latency, and tail latency.
|
|
| 2. |
- Scheuner, Joel, 1991, et al.
(author)
-
TriggerBench: A Performance Benchmark for Serverless Function Triggers
- 2022
-
In: Proceedings - 2022 IEEE International Conference on Cloud Engineering, IC2E 2022. ; , s. 96-103
-
Conference paper (peer-reviewed)abstract
- Serverless computing offers a scalable event-based paradigm for deploying managed cloud-native applications. Function triggers are essential building blocks in serverless, as they initiate any function execution. However, function triggering is insufficiently studied and inherently hard to measure given the distributed, ephemeral, and asynchronous nature of event-based function coordination. To address this gap, we present TriggerBench, a cross-provider benchmark for evaluating serverless function triggers based on distributed tracing. We evaluate the trigger latency (i.e., time to transition between two functions) of eight types of triggers in Microsoft Azure and three in AWS. Our results show that all triggers suffer from long tail latency, storage triggers introduce variable multi-second delays, and HTTP triggers are most suitable for interactive applications. Our insights can guide developers in choosing optimal event or messaging triggers for latency-sensitive applications. Researchers can extend TriggerBench to study the latency, scalability, and reliability of further trigger types and cloud providers.
|
|
| 3. |
- Steghöfer, Jan-Philipp, 1983, et al.
(author)
-
Design Decisions in the Construction of Traceability Information Models for Safe Automotive Systems
- 2021
-
In: Proceedings of the IEEE International Conference on Requirements Engineering. - 2332-6441 .- 1090-705X. ; , s. 185-196
-
Conference paper (peer-reviewed)abstract
- Traceability management relies on a supporting model, the traceability information model (TIM), that defines which types of relationships exist between which artifacts and contains additional constraints such as multiplicities. Constructing a TIM that is fit for purpose is crucial to ensure that a traceability strategy yields the desired benefits. However, which design decisions are critical in the construction of TIMs and which impact they have on the usefulness and applicability of traceability is still an open question. In this paper, we use two cases of TIMs constructed for safety-critical, automotive systems with industrial safety experts, to identify key design decisions. We also propose a comparison scheme for TIMs based on a systematic literature review and evaluate the two cases as well as TIMs from the literature according to the scheme. Based on our analyses, we thus derive key insights into TIM construction and the design decisions that ensure that a TIM is fit for purpose.
|
|
| 4. |
- Steghöfer, Jan-Philipp, 1983, et al.
(author)
-
The MobSTr Dataset - An Exemplar for Traceability and Model-based Safety Assessment
- 2021
-
In: Proceedings of the IEEE International Conference on Requirements Engineering. - 2332-6441 .- 1090-705X. ; RE 2021, s. 444-445
-
Conference paper (peer-reviewed)abstract
- The MobSTr dataset contains a number of artifacts for an autonomous driver assistance system, ranging from textual requirements to models for system design and models relevant to safety assurance. The artifacts provided are connected with traceability links created and managed with Eclipse Capra, an open source traceability management tool. The dataset builds upon a custom traceability information model that provides type safety and semantics for the trace links.MobSTr is intended for researchers that work on software and systems traceability as well as on model-based safety assurance. It is already being used in a number of studies, including research on trace link consistency, change impact analysis, and automated analysis of safety and timing requirements.
|
|
| 5. |
- Abdeen, Waleed
(author)
-
Reducing the Distance Between Requirements Engineering and Verification
- 2022
-
Licentiate thesis (other academic/artistic)abstract
- Background Requirements engineering and verification (REV) processes play es-sential roles in software product development. There are physical and non-physicaldistances between entities (actors, artifacts, and activities) in these processes. Cur-rent practices that reduce the distances, such as automated testing and alignmentof document structure and tracing only partially close the above mentioned gap.Objective The aim of this thesis is to investigate solutions w.r.t their abilityto reduce the distances between requirements engineering and verification. Twotechniques that are explored in this thesis are automated testing (model-basedtesting, MBT) and alignment of document structure and tracing (traceability).Method The research methods used in this thesis are systematic mapping, soft-ware requirements mining, case study, literature survey, validation study, and de-sign science.Results MBT and traceability are effective in reducing the distance between re-quirements and verification. However, both activities have some shortcoming thatneeds to be addressed when used for that purpose. Current MBT techniques inthe context of software performance do not attain all the goals of MBT: 1) require-ments validation, 2) checking the testability of requirements, and 3) the generationof an efficient test suite. These goals are essential to reduce the distance. We de-veloped and assessed performance requirements verification and test environmentgeneration approach to tackle these shortcomings. Also, traceability between re-quirements and verification suffers from the low granularity of trace links and doesnot support the verification of all requirements. We propose the use of taxonomictrace links to trace and align the structure of requirements specifications and ver-ification artifacts. The results from the validation study show that the solution isfeasible in practice. However, this comes with challenges that need to be addressed.Conclusion MBT and improved traceability reduce multiple distances betweenactors, artifacts, and activities in the requirements engineering and verificationprocess. MBT is most effective in reducing the distances when the model used isbuilt from the requirements. Traceability is essential in easing access to relevantinformation when needed and should not be seen as an overhead. When creatingtrace links, we need to consider the difference in the abstraction, structure, andtime between the linked artifacts
|
|
| 6. |
- Agrawal, Ankit, et al.
(author)
-
Model-Driven Requirements for Humans-on-The-Loop Multi-UAV Missions
- 2020
-
In: Proceedings - 10th International Model-Driven Requirements Engineering Workshop, MoDRE 2020. - : IEEE.
-
Conference paper (peer-reviewed)abstract
- The use of semi-Autonomous Unmanned Aerial Vehicles (UAVs or drones) to support emergency response scenarios, such as fire surveillance and search-And-rescue, has the potential for huge societal benefits. Onboard sensors and artificial intelligence (AI) allow these UAVs to operate autonomously in the environment. However, human intelligence and domain expertise are crucial in planning and guiding UAVs to accomplish the mission. Therefore, humans and multiple UAVs need to collaborate as a team to conduct a time-critical mission successfully. We propose a meta-model to describe interactions among the human operators and the autonomous swarm of UAVs. The meta-model also provides a language to describe the roles of UAVs and humans and the autonomous decisions. We complement the meta-model with a template of requirements elicitation questions to derive models for specific missions. We also identify common scenarios where humans should collaborate with UAVs to augment the autonomy of the UAVs. We introduce the meta-model and the requirements elicitation process with examples drawn from a search-And-rescue mission in which multiple UAVs collaborate with humans to respond to the emergency. We then apply it to a second scenario in which UAVs support first responders in fighting a structural fire. Our results show that the meta-model and the template of questions support the modeling of the human-on-The-loop human interactions for these complex missions, suggesting that it is a useful tool for modeling the human-on-The-loop interactions for multi-UAVs missions.
|
|
| 7. |
- Alégroth, Emil, 1984, et al.
(author)
-
Teaching scrum – what we did, what we will do and what impedes us
- 2015
-
In: Lecture Notes in Business Information Processing. - 1865-1348 .- 1865-1356. - 9783319186115 ; 212, s. 361-362
-
Conference paper (other academic/artistic)abstract
- This paper analyses the way we teach Scrum. We reflect on our intended learning outcomes, which challenges we find in teaching Scrum and which lessons we have learned during the last four years. We also give an outlook on the way we want to introduce and apply Scrum in our teaching and how we intend to improve the curriculum.
|
|
| 8. |
|
|
| 9. |
- Anders, G., et al.
(author)
-
Cooperative Resource Allocation in Open Systems of Systems
- 2015
-
In: Acm Transactions on Autonomous and Adaptive Systems. - : Association for Computing Machinery (ACM). - 1556-4665 .- 1556-4703. ; 10:2
-
Journal article (peer-reviewed)abstract
- Resource allocation is a common problem in many technical systems. In multi-agent systems, the decentralized or regionalized solution of this problem usually requires the agents to cooperate due to their limited resources and knowledge. At the same time, if these systems are of large scale, scalability issues can be addressed by a self-organizing hierarchical system structure that enables problem decomposition and compartmentalization. In open systems, various uncertainties-introduced by the environment as well as the agents' possibly self-interested or even malicious behavior-have to be taken into account to be able to allocate the resources according to the actual demand. In this article, we present a trust-and cooperation-based algorithm that solves a dynamic resource allocation problem in open systems of systems. To measure and deal with uncertainties imposed by the environment and the agents at runtime, the algorithm uses the social concept of trust. In a hierarchical setting, we additionally show how agents create constraint models by learning the capabilities of subordinate agents if these are not able or willing to disclose this information. Throughout the article, the creation of power plant schedules in decentralized autonomous power management systems serves as a running example.
|
|
| 10. |
- Berger, Thorsten, 1981, et al.
(author)
-
The state of adoption and the challenges of systematic variability management in industry
- 2020
-
In: Empirical Software Engineering. - : Springer Science and Business Media LLC. - 1382-3256 .- 1573-7616. ; :25, s. 1755-1797
-
Journal article (peer-reviewed)abstract
- Handling large-scale software variability is still a challenge for many organizations. After decades of research on variability management concepts, many industrial organizations have introduced techniques known from research, but still lament that pure textbook approaches are not applicable or efficient. For instance, software product line engineering-an approach to systematically develop portfolios of products-is difficult to adopt given the high upfront investments; and even when adopted, organizations are challenged by evolving their complex product lines. Consequently, the research community now mainly focuses on re-engineering and evolution techniques for product lines; yet, understanding the current state of adoption and the industrial challenges for organizations is necessary to conceive effective techniques. In this multiple-case study, we analyze the current adoption of variability management techniques in twelve medium- to large-scale industrial cases in domains such as automotive, aerospace or railway systems. We identify the current state of variability management, emphasizing the techniques and concepts they adopted. We elicit the needs and challenges expressed for these cases, triangulated with results from a literature review. We believe our results help to understand the current state of adoption and shed light on gaps to address in industrial practice.
|
|
