Benny Akesson

Senior Research Fellow @ TNO-ESI | Endowed Professor @ University of Amsterdam

Master Thesis Project Leads to Conference Publication on Microservice Architecture Anti-Patterns at SEAA 2024

I am delighted to announce that our paper, “Graph-based Anti-Pattern Detection in Microservice Applications,” has been accepted for publication at the 50th Euromicro Conference Series on Software Engineering and Advanced Applications (SEAA). This paper stems from Amund Lunke Røhne’s master thesis project, which he conducted as an internship with TNO-ESI under the supervision of myself and Ben Pronk. This achievement showcases how exceptional work by master students can lead to publications in established conferences.

Our paper addresses a significant challenge in the evolution of microservice applications: as the microservice architecture evolves, architectural anti-patterns may emerge. These anti-patterns are challenging to detect and manage due to their informal natural language definitions and the lack of automated tools. To tackle this, we propose an automated methodology for detecting architectural anti-patterns related to microservice dependencies. A key component of this methodology is the novel Granular Hardware Utilization-Based Service Dependency Graph (GHUBS) model, which is automatically inferred from telemetry data. We have formalized three commonly known anti-patterns and developed algorithms to detect them within the GHUBS model. This methodology is supported by an open-source tool that automatically identifies and visualizes these anti-patterns. We validated our approach using both synthetic data and a case study of a popular microservice benchmarking suite, demonstrating successful detection of the formalized anti-patterns.

Congratulations to Amund on the acceptance of your paper! Your work has made both TNO-ESI and the Software Engineering program at the University of Amsterdam very proud!

Merrick Oost-Rosengren Successfully Defends Thesis on Early Component Verification using Colored Petri Nets

Just before the summer holidays, another master student has finished his project. This time, it is Merrick Oost-Rosengren who successfully defended his thesis “Formal Verification of Components through Mirroring of Coloured Petri Nets“. Parts of this work was done as an internship with TNO-ESI in collaboration with Thales.

This research addresses a challenge in distributed component-based systems, where different components are developed by different teams, perhaps even different organizations, over time. The problem is that when components are ultimately integrated, their interactions may cause deadlocks, livelock, or unbounded memory behavior. Fixing such problems late in the development process is very costly. An alternative approach is to model components, or component interfaces, early in the design process and use model checking to verify the behavior of the component and its interactions. However, we may not know which components it will interact with yet. Perhaps they have not yet been developed?

The thesis addresses this challenge by proposing a methodology and corresponding tool chain, where components as modelled as Colored Petri Nets from which a verification model, a mirror of the component that captures relevant possible behaviors of interacting components, is automatically generated. As a part of the methodology, the thesis proposes a new class of Colored Petri Nets called Mirrorable Open Colored Petri Nets. This class combines features of existing Colored Petri Nets and Open Petri Nets, and also adds extra semantics to allow the component to be mirrored. It also describes methods for mirroring such a net and fusing the mirror with the original component, such that the components and its interactions can be verified using reachability analysis.

We congratulate Merrick on his successful defense and wish him a lovely summer!

Software variability is as relevant as ever as a driver of complexity in high-tech equipment

Earlier this week, TNO-ESI arranged a webinar with Jacob Krüger, Assistant Professor at Eindhoven University of Technology. In the presentation “Do We Still Need This? Managing Variability in Modern Software Systems” he presented his research on development and evolution of variant-rich software systems. The presentation explained how successful systems are often cloned to create new variants until managing the variability becomes too complex and expensive. It discussed the transition from cloning towards platform-based software architectures and compared the development costs for new features and new variants, respectively, for the two cases, based on empirical data from industry. These insights are valuable to inform decision-making about when adopting a platform-based approach is strategic. However, Jacob also made clear that moving to a platform-based approach introduces its own challenges, such as ensuring software comprehension and quality, analyzing variability, aligning software and hardware release schedules, and deprecation of variable features.

The webinar attracted an audience of approximately 40 people from TNO-ESI, ASML, Thales, Canon, Vanderlande, ThermoFisher, and Radboud University Nijmegen. This strongly suggests that variability is still a main concern both in systems and software engineering that affects all parts of system development, from early architecting to implementation, testing, and evolution. I was thrilled to see that there was a lively discussion with questions and remarks. In retrospect, I wish we would have reserved more time to keep the conversation going. If you would like to discuss your particular variability challenges or ideas with Jacob, feel free to contact him.

TNO-ESI looks forward to arranging more webinars with experts from our eco-system of academic and industry partners in the field of software and system engineering for high-tech equipment.

TNO-ESI and Academic Partners Deliver ASCI PhD Course on Design and Implementation of Real-time Systems

The Netherlands boasts a world-leading high-tech manufacturing industry renowned for constructing distributed real-time systems of continuously growing complexity. These systems must meet stringent timing requirements to ensure the delivery of mission-critical functionalities. To create interest in the high-tech equipment domain and prepare PhD students in Computer Science to address its performance challenges, TNO-ESI has co-created and delivered a one-week PhD course Design and Implementation of Real-time Systems together with academic partners from Eindhoven University of Technology, University of Twente, and University of Amsterdam. The course is given in the context of the Advanced School for Computing and Imaging (ASCI), a Dutch research school for high-quality research and education in computer systems and imaging systems. ASCI encompasses almost all Dutch universities with computer-science departments. The main goals of ESI involvement in this course were to make participants aware of TNO and its role in society and industry and position it as a possible future employer, and creating awareness of TNO-ESIs vision and work in the area of system performance engineering.

The course is focused on providing an overview of selected timing-sensitive applications and the current research landscape on real-time systems and explaining the rationale behind considering real-time requirements in system software design. Through a series of lectures and hands-on labs, the course covers selected topics from scheduling algorithms, priority assignments, resource sharing, resource reservation, together with their implementation in real-time operating systems. It further discusses emerging challenges and practices in an industrial context, based on empirical surveys and experience from TNO-ESIs applied research on telemetry-based system performance engineering for purposes of performance optimization, verification, and diagnostics.

This first instance of the course was given at the Carlton President Hotel in Maarsen, outside Utrecht between June 10 – 14. 15 PhD students from universities all over the Netherlands researching a broad range of topics in computer science participated in the course. TNO-ESI was in the spotlight during the last day of the course. In the morning, I introduced the high-tech equipment domain and its complexity drivers and explained how new model-based engineering methodologies where needed to address them. Next, my colleague Bram van der Sanden presented our view on the field of System Performance Engineering, along with its focus areas and best practices. This was followed by two concrete examples from our system performance research: Kostas Triantafyllidis presented his work on performance analysis and diagnosis with ASML, followed by a presentation by me about performance verification and conformance checking in microservice systems based on our work with Thales.

The course was well-received by the participants and the contents were rated 8.7/10 in the evaluation. We very much enjoyed the experience of creating and delivering this course together with our academic partners. Thank you Kuan-Hsun Chen (leader of the initiative), Mitra Nasri, and Geoffrey Nelissen for the excellent collaboration in organizing this course. Thanks to Kay Heider and Christian Hakert for leading the hands-on exercises. We are also thankful to invited speakers Bram van der Sanden and Kostas Triantafyllidis.

Faezeh Saadatmand Wins Best Paper Award at ICPS

Good news everyone! Our paper “Automated Derivation of Application Workload Models for Design Space Exploration of Industrial Distributed Cyber-Physical Systems” won the Best Paper Award at the 7th IEEE International Conference on Industrial Cyber-Physical Systems (ICPS). This is an impressive feat, especially considering that it is the first paper first-authored by Faezeh Saadatmand, PhD student at Leiden University. Congratulations Faezeh!

The paper tackles an urgent issue: the growing complexity of industrial cyber-physical systems, which is driving up development and maintenance costs. As these systems incorporate more functions, the number of hardware and software components increases rapidly, making it harder to analyze and optimize their performance. Model-based methodologies have been proposed as a means to manage complexity and increase productivity of engineers by using models as a base for specification, communication, analysis, and synthesis of artifacts like documentation, simulation models, and code. But who is going to make models of systems with tens of compute nodes and hundreds of software processes, especially when increased customization results in a unique configuration for each manufactured system? This research addresses this need by introducing an automatic method for deriving an application workload model. This model, based on trace analysis, captures computation and communication activities within an application in a timing-agnostic manner. The method was validated through a case study on an ASML Twinscan lithography machine, showing high accuracy in representing real application workloads.

This paper is a result from the Design Space Exploration 2.0 (DSE2.0) project, one of four academic projects co-funded by TNO-ESI and NWO as a part of the Mastering Complexity (MasCot) program.



Reflections on RTAS 2024: A Successful Symposium in Hong Kong

The 30th IEEE Real-Time and Embedded Technology and Applications Symposium (RTAS 2024) is over. As I am enjoying a last local beer at Hong Kong airport before getting on my flight home, it feels like a good opportunity to reflect on this years successful edition of the conference.

The preparation of this conference has taken me, as the Program Chair, about one year. While it was a lot of work, I enjoyed it a lot because I got to work with dedicated, clever, and proactive people from the real-time systems community to make it happen. This year, we received 124 paper submissions from around the world, marking a 40% increase from last year. This suggests that the community is recovering well post-pandemic and there is a clear interest in the topics covered by the conference.

The Program Committee comprised 61 reviewers, supported by 87 sub-reviewers, blending expertise from a diverse group of experts in both academia and industry. Each submission was evaluated through at least four reviews, resulting in a total of nearly 500 double-anonymous expert reviews. Based on these reviews, a brief author response to the reviews to clarify misunderstandings, and online discussions, 29 papers This resulted in an acceptance rate of 23.3%, which means it was very competitive! The accepted papers formed the basis for the outstanding technical program.

Having spent so much time preparing the conference, I really wanted the execution to go smoothly, giving all 100 registered participants a good experience of the technical program. I was happy to see that the preparation had paid off and that there was very little work for me during the conference itself. The session chairs did an excellent job introducing the speakers and managing the sessions. The only curve ball was that one author did not get their visa on time, so we had to quickly improvise a setup for giving remote presentations. This was handled beautifully by the local organizers and I would like to thank Nan Guan and his colleagues for their hard work and attentiveness. From my perspective, the local arrangements worked perfectly!

I was impressed with the quality of the presentations of this edition. Despite the theoretical nature of much of the research, I was pleased to see that presenters managed to focus on their main messages and used lots of figures and animations to get high-level concepts across and referring to the papers for the details. I am asking myself if we, as a community, are getting better at presenting or if this is a side-effect of that we had to reduce the presentation time of the papers from 25 minutes to 18 minutes to fit the increased number of papers in the sessions. Whatever it was, I liked it and hope that this sets the bar for next time!

There were many excellent contributions in the technical program. From Marco Caccamo’s Outstanding Technical Achievement and Leadership Award lecture, we learned that there are many software-based memory management techniques and execution models that can improve the predictability of commercial-of-the-shelf (COTS) multi-processor systems-on-chip and make them suitable for hard real-time or mixed-criticality applications. This is an area where I feel we are making good progress. COTS systems are getting increasingly configurable and observable, allowing our community to propose solutions for real-time systems that do not require custom hardware. This lowers the threshold for transferring our research results to industry significantly.

Looking at the topics addressed at the conference, I was surprised by the large number of papers looking at the intersection of real-time systems and security, so many we needed two sessions to fit all of them! I particularly remember work considering how to ensure control-flow integrity when faced with malicious actors. Two papers looked into how this could be addressed leveraging features recently introduced in COTS platforms. There were also works looking at the effects of performance interference, such as random delays, on cyber-physical systems and how they could be mitigated using robust control strategies in stochastic control systems.

Considering the technical solutions that were presented, I really enjoyed the work by Soni et al. that addressed the scalability of timing analysis of AFDX networks in the avionics domain. The paper proposed a hybrid approach that combined an exact analysis using model checking with a faster and more pessimistic analysis using network calculus. The key idea was to use the bounds provided by network calculus to prune the state space for the model checker to reduce analysis time. I really liked that this hybrid approach worked both ways and allowed the exact analysis done so far by the model checker, to be leveraged by the network calculus to reduce its pessimism. This allowed the proposed analysis to scale to large industrial use cases with more than 1000 network flows.

There is of course a lot more to say about the conference and the papers featured in it, but it is time to fly home.
I want to conclude by thanking all the people that contributed to the organization of the conference. I also want to thank all authors who submitted their work to RTAS 2024. Lastly, I want to thank all conference participants for coming to Hong Kong to listen, learn, discuss, and network. That is what the community is all about!

For more information about RTAS 2024 and the papers featured in its program, please refer to the RTAS 2024 website.

ESI Symposium 2024: A Showcase of Cutting-Edge Research in High-tech Equipment

I had a blast at the ESI Symposium in Veldhoven! It may have been the best ESI Symposium I have visited so far! It is great to see the innovation chain for Dutch high-tech equipment come together and share challenges, exciting new research results, as well as success stories from our implementation partners.

The Symposium also showcased the progress of our academic programs. The Mastering Complexity (MasCot) program, now a veteran at the ESI Symposium, contributes new engineering methodologies to help us manage increasing system complexity and develop next-gen high-tech equipment efficiently and cost-effectively through all development phases, from early architecting to implementation, testing, and evolution. As the program enters its fourth year, the current focus is on rounding off much of the research and transfer developed knowledge and proof-of-concepts to ESI and the industry partners.

The Symposium also introduced our recently started ZORRO project, which is set to change the way we handle system malfunctions in cyber-physical systems. With intelligent diagnostics, ZORRO is on a mission to significantly reduce downtime costs and enhance system reliability. Interested to learn more? Reach out or stay tuned to hear more as the research develops!

Mastering Complexity at ICT.Open

This week saw another edition of NWO ICT.OPEN, a yearly event that brings scientists from all ICT research disciplines and industries together to learn, share ideas, and network.

My colleague Rosilde Corvino and I from TNO-ESI chaired the Mastering Complexity for Cyber-Physical Systems track. This track was kicked off with a keynote about software architecture for strategic advantage, given by Erik Schepers, Chief Software Architect at Thales. Two presentations followed about using large language models to manage software legacy and task-oriented programming for the Internet of Things, respectively. Approximately 30 participants attended the track, highlighting its relevance and the keen interest in cyber-physical systems. The event also saw a few projects from ESI’s Mastering Complexity (MasCot) academic program, DSE2.0 and Software Restructuring, being present with posters.

Lastly, the poster “Models for Legacy Software Systems,” authored by ESI colleagues Joe Reynolds, Nan Yang, Rosilde Corvino, Anca-Maria Lichiardopol, and Joost van Zwam, won the best poster award at the ICT.Open conference. The work has been prized for its innovation, applicability, and clarity of presentation. Congratulations to the team for this achievement, and kudos to Joe Reynolds for his outstanding presentation, demo, and poster explanation.

Next Tuesday, it is time for the next event, the crown jewel of ESI, the ESI Symposium 2024. It is still possible to register for free. I hope to see you there!

Keynote on Managing Variability and Evolution in High-tech Equipment at FOSD Meeting 2024

I had the distinct honor of opening this year’s Meeting on Feature-Oriented Software Development (FOSD Meeting) with a keynote titled “Managing Variability and Evolution in High-tech Equipment”. FOSD Meeting is a yearly informal meeting to bring together the community of researchers working on feature-oriented software development. This year, the event was hosted by TU/e between April 9 – 12.

The keynote covered complexity trends in the high-tech equipment domain, ESI and its role in the high-tech innovation eco-system, and two examples of how variability and evolution were tackled using model-based methodologies at the level of the software architecture in our projects with Thales. The keynote was appreciated by the organizers of the event and the group of 35 participants, mostly from (German) universities but also from ESI’s international applied research partner DLR.

Reflecting on my experience, I was pleasantly surprised at the broad expertise in this community, which covered modelling, software engineering, and performance and I wished I could have stayed around to enjoy the rest of the event. I am happy to see that the keynote triggered some concrete follow ups that can help us link members of this academic community to research in the high-tech equipment ecosystem.

PhD Defense on Governance of Complex Cyber-infrastructure

Today, I chaired a PhD committee at the University of Amsterdam. The PhD candidate Mostafa Mohajeri Parizi defended his dissertation “An Agent-based Approach to the Governance of Complex Cyber-Infrastructures”. The dissertation explores the impact of digitization on society and the need for engineering approaches to ensure that digital systems comply with regulations. Mostafa did his PhD research in the Complex Cyber-Infrastructure (CCI) group under the supervision of TNO colleague Tom van Engers (Principal Scientist ISP DS). The work centers on the use of computational agents and norms to develop tools and methodologies for governing socio-technical systems. The study introduces ASC2, an agent-based programming framework built on the belief-desire-intention model, alongside a scalable multi-agent system environment. It emphasizes the integration of mainstream software development tools into agent-based programming and enhances transparency and decision-making in agents by incorporating context-dependent preferences. Furthermore, the dissertation proposes a modular architecture for integrating norms into multi-agent systems, allowing for the flexible adoption and reasoning of norms without compromising agent autonomy. This is illustrated through two case studies demonstrating the framework’s application in coordinating agent actions and aligning them with encoded laws. The research highlights the potential of agent and norm models in improving the design and policy-making of digital infrastructures.

Mostafa did a good job presenting and defending his work and the committee were impressed by the breadth of the research. We hope the newly minted Dr. Mohajeri Parizi enjoyed the ceremony and the celebration with his friends and family and wish him all the best of luck in his future career.