Benny Akesson

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

Serving the Real-time Systems Community

I have been a part of the academic real-time systems community for many years by serving on the technical program committee of many key conferences, as well as reviewing articles for the real-time systems journal. This year, I am serving the real-time systems community in the following four ways.

I look forward to working with and serving the community in these roles.

Seven Brave Software Architects/Engineers from Thales Completes MOANA-CBS Course using Eclipse ComMASuite

ESI (TNO) has given another instance of the course “Modelling and Analysis of Component-based Systems” (MOANA-CBS), developed as part of the applied research project DYNAMICS, at Thales. A batch of 7 brave software engineers participated to learn more about how to identify and resolve a range of interface model quality problems, such as deadlocks, livelocks, and race conditions. This instance of the course was adapted to be based completely on the latest version of Eclipse ComMASuite, the open source version of ComMA, making the course accessible to a large general audience. Previously, the course has been given with an internal version of ComMA or by using Petri nets as the interface modelling language.

 In total, over 110 participants, mostly with backgrounds in system and software engineering, have followed different versions of this course. This time, two former Thales participants assisted in giving the course, both by presenting contents and supervising exercises, to help Thales transfer the knowledge developed in the DYNAMICS project into the organization. We look forward to further improve the material and keep sharing the knowledge we developed with Thales and other interested parties.

Master Thesis on Formal Verification of Software Interfaces Defended

Today, Bart-Jan Hilbrands, a master student from UvA supervised by myself and my ESI colleague Debjyoti Bera, successfully defended his master thesis “Verification of Inter-Dependent Interfaces in Component-Based Architectures”. The thesis considers formal verification of ComMA components with multiple interfaces with inter-dependent behavior, caused by three different types of functional constraints. The four main contributions of the thesis are: 1) A formalization of each type of interface constraint, defining how they should restrict behavior, 2)  a set of assumptions, describing properties that help ComMA users avoid creating specifications with termination issues, 3) methods for encoding the behavior of these constraints into existing Petri net representations of interfaces, and 4) methods for validating whether a set of given constraints is encoded correctly into a given Petri net. The theory is supported by a prototype implementation ComMA.

Bart presented his thesis well and expertly answered questions from the committee. We thank Bart for his excellent work and wish him good luck is his future career. First off, he will continue working with me and Deb to publish his work as a paper.

Vacancy for a PhD in Energy Labels for Digital Services

Back in July, I announced that our project proposal “Zero-Waste Computing: Energy Labels for Digital Services” was granted for the Science and Design PhD program at the University of Amsterdam. Now, the Parallel Computing Systems (PCS) group  is looking for a suitable PhD candidate for this project. Among other things, this involves modelling and monitoring to determine how energy is consumed in digital services whose computations are distributed over device, edge, and cloud.

Find a more detailed description of the vacancy, as well as instructions for how to apply here. The application period ends on October 18.

Article about Survey-based Study into Industry Practice in Real-time Systems in Real-time Systems Journal

It has been almost a year since we published the first survey-based study in the area of real-time systems at the Real-time Systems Symposium (RTSS) back in December 2020. The paper was entitled “An Empirical Survey-based Study into Industry Practice in Real-time Systems” and had the ambitious goal of addressing the gap between academic research and industry practice through an empirical survey-based study into industry practice. The survey had five objectives: 1) Establish whether timing predictability is of concern to the real-time embedded systems industry, 2) Identify relevant industrial problem contexts, including hardware platforms, middleware, and software, 3) Determine which methods and tools are used to achieve timing predictability, 4) Establish which techniques and tools are used to satisfy real-time requirements, and 5) Determine trends for future real-time systems. The survey was completed by 120 industry practitioners in the field of real-time embedded systems, which allowed interesting observations and insights to be made about the characteristics of the systems being developed today and important trends for the future.

Now, almost one year later, I am happy to announce that an extended version of our RTSS paper has been accepted for publication in the Real-time Systems journal. The title of the article is “A Comprehensive Survey of Industry Practice in Real-Time Systems“. The main extensions in the article include: 1) a discussion of potential threats to validity of the survey and its results, as well as the steps taken to mitigate them, 2) a statistical analysis and discussion of the results of the survey, in the context of its five objectives, 3) a discussion of the results of a quiz aimed at determining if the aggregate findings of the survey are common knowledge in the real-time systems community. In addition, more aggregated data from the survey has been released, allowing interested readers to further delve into the similarities and differences between the avionics, automotive, and consumer electronic domains.

We hope that you enjoy the article!

Paper about Model-driven System Performance Engineering Accepted at ESWEEK Industry Session

The System Performance Expertise Team at ESI (TNO) has worked for a long time to consolidate our many years of experience across projects and companies. This effort has now culminated in a paper entitled “Model-driven System Performance Engineering for Cyber-physical Systems“, which has been accepted for the industry session at the Embedded Systems Week (ESWEEK) in October.

The paper describes ESI’s current view on the field of System-Performance Engineering (SysPE). SysPE encompasses modeling formalisms, methods, techniques, and industrial practices to design systems for performance, where performance is taken integrally into account during the whole system life cycle. Industrial SysPE state of practice is generally model-based. Due to the rapidly increasing complexity of systems, there is a need to develop and establish model-driven methods and techniques. To structure the field of SysPE, the paper identifies: (1) industrial challenges motivating the importance of SysPE, (2) scientific challenges that need to be addressed to establish model-driven SysPE, (3) important focus areas for SysPE and (4) best practices. A survey was conducted to collect feedback on our views. The responses were used to update and validate the identified challenges, focus areas, and best practices. The final result is presented in this paper. Interesting observations are that industry sees a need for better design-space exploration support, more than for additional performance modeling and analysis techniques. Also tools and integral methods for SysPE need attention. From the identified focus areas, scheduling and supervisory control is seen as lacking established best practices.

The paper will be presented as a part of Industry Session 2 at ESWEEK on October 12. The second talk of that session presents why and how ITEC, Nexperia, a world-leading manufacturer of semiconductor equipment, is moving towards model-driven system-level development. The session ends with a moderated Q&A. Since ESWEEK is an online event this year, you can register for 20 USD if you want to attend the conference and the session.

Update: The video of the Industry session is now available:

Project Proposal about Energy Labels for Digital Services Granted

It is my pleasure to announce our project proposal entitled “Zero-Waste Computing: Energy Labels for Digital Services” has been granted for the Science and Design PhD program at the University of Amsterdam. Ana Lucia Varbanescu is the main applicant for this project, with Anuj Pathania and myself as co-applicants. The project proposal was supported by Surf, ESI (TNO), Barcelona Supercomputing Center, and ASTRON.

The project addresses the issue that digital services are getting increasingly prevalent in society and are vital to the Dutch economy, already reaching 60% of GDP. However, they come with a significant, rapidly-increasing energy cost, raising sustainability concerns, since a mid-size datacenter alone consumes as much energy as a small town. However, datacenters are only the final link in a digital chain. Users interacting with devices — mobile phones, tablets, or laptops — trigger entire digital chains, combining multiple communicating computing layers and data transfers: from the device itself, through the edge, to the datacenter. Each layer has its own computing infrastructure (see figure). At each layer, decisions are made about how, where and when applications are running and/or data are transferred. These decisions have a significant impact on the user-perceived quality-of-service (QoS), but also on the energy consumption – per layer, and for the entire digital chain. The energy footprint of different devices along the chain might be known, but the actual energy consumed by the application is unknown, because it depends on infrastructure choices, and on user QoS requirements, and on mapping decisions made on the edge and in the datacenter. Thus, the energy efficiency, i.e., the amount of energy consumed to perform the actual task at hand, is largely unknown, for most digital chains.

We argue that the first step to reduce waste in computing is to quantify the energy efficiency of end-to-end digital chains. Our project focuses on designing an integrated framework (i.e., the methods, metrics, and tools) for this quantification effort. Specifically, we aim to define a reference architecture of digital chains, use it to define an analytical digital-chain energy-efficiency model that exposes the factors that impact energy efficiency along the chain, and support it with a high-level functional simulator to assess different operational scenarios and parameters that affect the energy efficiency of digital chains.

This is a small project funding only a single PhD student. More momentum is required to further advance this area and make a step from only monitoring the energy consumption of digital chains to also include actuation, e.g. energy minimization through workload redistribution, subject to performance constraints. We are currently looking for interested parties to collaborate with us on this topic in future project proposals.

Modelling and Analysis of Component-based Systems (MOANA-CBS) Course Update

Last year, ESI (TNO) and Thales developed a two-day course on Modelling and Analysis of Component-based Systems (MOANA-CBS) as a part of the DYNAMICS project. The course addresses the trend to tackle software complexity by decomposing monolithic software into loosely coupled components. While this trend manages complexity through improved scalability, adaptability, and testability, it also increases concurrency and asynchronous communication. This may in turn lead to an explosion in possible behaviors. As a consequence, it is hard to oversee the behavior of such systems, resulting in situations where early design errors are detected much later in the system lifecycle with exponentially rising costs. The course targets software and system architects/engineers involved in design and implementation of components and interfaces, and teaches methods for modelling and analyzing them to guarantee that they are free from deadlocks, livelocks, races, and buffer overflows.

We piloted the course material both in academic and industrial environments. The former was as a part of my course Embedded Software and Systems, a part of the Software Engineering Master  at the University of Amsterdam. The latter was as a part of the Accelerate program run by Thales and Luminis to accelerate their medior software talent to a senior level. Thales recently published an interview with Patrick Schulenberg, one of the participants in the program, about his experience. Patrick explains that the program has been an excellent opportunity for him to grow within the company, and mentions the positive impact of our course: “ESI taught a class about interface modeling, sharing their experiences with using the Comma framework at Philips – this was a trigger for us to put practical modeling proficiency on our roadmap”.

Currently, we are developing an updated version of the MOANA-CBS course that will have closer ties to ComMA, an open-source domain-specific language initially developed by Philips and ESI that is currently used by several companies. This update will strengthen the practical applicability of the course for users of ComMA, and will introduce unfamiliar users to interface modelling and analysis through hands-on experience with the tool. The new version of the course is expected to be ready in Q3.

Paper Accepted at PNSE 2021

It has been almost a year since Mohammed (Madiou) Diallo submitted his bachelor thesis “Towards the Scalability of Detecting and Correcting Incompatible Service Interfaces“, which he carried out in the context of the DYNAMICS project, an applied research project between ESI (TNO) and Thales. After the thesis was finished, we discussed publishing the work as a paper and one year later, a slightly restructured and simplified version of the story has been accepted at the International Workshop on Petri Nets and Software Engineering (PNSE), a workshop co-located with the Petri Net conference.

The accepted paper is entitled “Synthetic Portnet Generation with Controllable Complexity for Testing and Benchmarking” and presents a heuristic-driven method for synthetic generation of random portnets, a kind of Petri Nets suitable for modelling software interfaces in component-based systems. The method considers three user-specified complexity parameters: the expected number input and output places, and the prevalence of non-determinism in the skeleton of the generated net. An implementation of this method is available as an open-source Python tool. Experiments demonstrate the relations between the three complexity parameters and investigate the boundaries of the proposed method. This work was helpful for the DYNAMICS project, as it allowed us to synthetically generate a large number of interfaces of varying complexity that we could use to evaluate the scalability of existing academic tools for adapter generation.

 

 

Open-source ComMA v0.1.0 officially released

Last week, the open sourcing of ComMA (Component Modelling and Analysis) in the context of the Eclipse Foundation, saw another milestone. The first version Eclipse CommaSuite is now online in the form of Release 0.1.0. ComMA is a set of DSLs used to (partially) specify the behavior of components and their interfaces, including time and data constraints. On the basis of these specifications, a number of artifacts can be automatically generated, including run-time monitors that validate compliance with the specification can be generated, visualizations, timing statistics, documentation, test cases, and adapters. Many of these features will be included in later releases of ComMA, and some of them have yet to emerge from research projects as mature features.

ComMA was originally developed by ESI and Philips, but more recently in collaboration with a growing number of other companies. For example, the DYNAMICS project in which ESI works together with Thales, we are currently investigating how adapters can be semi-automatically generated to bridge differences between components implementing different versions of interfaces. This work has been previously mentioned in an article in Bits & Chips, as well as in a paper. Currently, three master students from my Embedded Software and Systems course at UvA are also doing their graduation projects in the context of evolution of ComMA interfaces, looking into aspects of data dependencies, interface dependencies, and static impact analysis. We look forward to seeing the results of their work this summer.

You can read more about ComMA in this news article TNO published this week.
Update: The news article is now also published in Bits & Chips