Program

February 19th (Theme: Microservice Design)

8:00	Registration desk open Location: Room F.212
9:15 10:00	Welcome and Opening Speech Speakers: Sabine Sachweh, Fabrizio Montesi Opening speech to welcome all the attendees and introduce the organisation and the environment around the conference. Location: Room F.211
10:00 10:20	Coffee Break Location: Room F.212
10:30 12:10	Foundations of Design Microservices: A Taxonomy Author: Stefan Tilkov Paper Abstract Slides A microservices services architecture has become a standard way to approach the modular design of large scale systems. But while there are some traits that most practitioners can agree on, such as independent deployment, choice in implementation details, polyglot persistence, and benefits such as isolation, better parallelization, and improved scalability, there are still some vast differences between the different approaches taken in practice. In this talk, we will categorize different ways to approach the architectural style, and highlight difference, benefits, and downsides of various interpretations found in projects. Innovation, not Novelty: Three models for Microservices Architecture Design Author: Leif Beaton Paper Abstract One of the most significant factors when moving to microservices is network design and implementation. Communication between services happens over the network, rather than in-memory, as is the case in traditional monolithic designs. Consequently, in this talk, Leif Beaton, Senior Technical Solutions Architect, will outline the three models that constitute NGINX’s reference architecture for microservices, each representing an increasing level of sophistication and power. Microservices Architectures and Technical Debt: A Self-adaptation View? Authors: Ananya Chhonker; Rogério de Lemos Paper Abstract Slides Since there is no primary or secondary studies investigating MSA in the context of technical debt, the goal of this work is to assess the impact of MSA into technical debt, and probe whether self-adaption can be use as a means to facilitate maintainability and evolvability of MSA-based software systems. Viewpoint-specific Model-driven Microservice Development Author: Philip Wizenty Paper Abstract Slides Microservice Architecture is an upcoming architectural style for distributed and service-based software system, with a strong focus on loosely coupled and highly cohesive services. Model-driven Development is an approach to software engineering, which uses models to abstract from the system’s complexity for the better understanding of the problem and risk identification at the start of the development process. The usage of MDD for developing service-based software systems can be beneficial. In our work, we present a holistic Model-driven Development approach for DevOps-based microservice development. Chair: Luís Cruz-Filipe Location: Room F.211
12:10 13:10	Lunch Location: Room F.212
13:20 14:20	Domain-Specific Service Decomposition with Microservices API Patterns Speaker: Olaf Zimmermann Slides Abstract of the keynote | Microservice API Patterns Website Chair: Saverio Giallorenzo Location: Room F.211
14:20 15:10	Design Support Towards customizing multi-tenant Cloud applications using non-intrusive microservices Authors: Phu H. Nguyen; Hui Song; Franck Chauvel; Erik Levin Paper Abstract Slides The customization requirements from different customers are often beyond what software vendors can offer in advance, at design-time. Enabling tenant-specific customizations in cloud-based multi-tenant Software-as-a-Service (SaaS) requires a novel approach. This paper proposes a Microservice-architecture-based non-intrusive Customization framework (MiSC-Cloud) to enable deep customization of SaaS. How to Synchronize Microservices Authors: Sebastian Copei; Albert Zündorf Paper Abstract We start by splitting an University wide data model for student data into four example microservices. Then we address the problem of data synchronisation for these microservices, systematically. Chair: Olaf Zimmermann Location: Room F.211
15:10 15:30	Coffee Break Location: Room F.212
15:30 16:20	Design Experiences Migrating Monoliths to Microservices: A Survey of Approaches Author: Eberhard Wolff Paper Abstract Slides Usually microservices are not build on a greenfield but a monolith is migrated into a microservices architecture. This presentation shows goals and constraints of a migration strategy. A blueprint strategy is presented which is not limited to architecture but also covers infrastructure. Finally alternative approaches with their advantages and disadvantages are discussed. Why Microservices Fail: An Experience Report Author: Eberhard Wolff Paper Abstract Microservices are now widely used. However, not all projects successfully apply microservices principles. The presented overview of typical failure scenarios is important to use microservices more effectively, and to come up with novel architecture approaches. To support future projects, approaches to mitigate the problems are shown. Chair: Claudio Guidi Location: Room F.211
16:20 17:00	Short talks Microservices are not a silver bullet - challenges and benefits of the Microservices architectural style Author: André Fachat Paper Abstract Microservices are an approach for developing and deploying services that make up an application. Microservices, as the name implies, suggest breaking down an application into smaller “micro” parts, deploying and running them separately. The main benefit promised by this approach is faster time-to-market for new functionalities due to better technology selection and smaller team sizes. Experience shows, however, that Microservices are not the silver bullet in application development and projects can still fail or take much longer than expected. To evaluate the Microservices approach, we first look at the perceived promises of the Microservices architectural style. Then we point out some of the pitfalls and challenges associated with using Microservices. In the second part we will give our opinion and experience how to set up Microservices projects to avoid these pitfalls. We will revisit and discuss the (perceived) promises of Microservices in the light of what we learned. A Class Concept for Microservices to Manage Dynamic Complexity and Code Reuse Authors: Lukas Reinhardt; Marcus Hilbrich Paper Abstract Slides To manage the complexity of software projects is an ongoing and rising challenge for decades. Complex software is hard to realize, hard to understand, hard to verify, hard to maintain and leads to failing projects [8]. To manage the rising complexity, numerous different strategies are developed. Using microservices is such a strategy. The overall software is devised vertically into services. Idealistically, the services are independent and can be developed independently of each other. Based on our observation, the remaining communication of services is still a challenge and focusing on service development, the complexity of the communication (dynamic complexity) is not managed well. In addition, code sharing [2], abstraction of services, and cross-cutting concerns are also challenges for microservices. In this paper, we present an extension of the microservice concept with object orientation. Based on object orientation, communication of services (dynamic complexity) can be managed explicitly, abstraction can be realized, and code sharing becomes possible. A first evaluation of our concept and a prototype realization indicates that the overall complexity of the software can be reduced significantly, while not harming the microservice development and deployment process. Chair: Nhiem Lu Location: Room F.211

February 20th (Theme: Microservice Development)

8:00	Registration desk open Location: Room F.212
9:00 10:00	Understandable Microservices Speaker: Fabrizio Montesi Slides Abstract of the keynote Chair: Sabine Sachweh Location: Room F.211
10:00 10:20	Coffee Break Location: Room F.212
10:30 12:10	Foundations of Development Do Microservices Prevent High Qualitative Code? Authors: Marcus Hilbrich; Christine Jakobs; Matthias Werner Paper Abstract Slides During the last years many industry areas started to use microservices. They show advantages like scalability, independent service development, and complexity management. Nevertheless, from a researcher point of view we observe also drawbacks in using microservices. The aim of this paper is to present some of them to initiate a discussion whether they are caused by misconception or by misuse of the concept. We present three observations we want to emphasize and use the microservice definition from the paper of Lewis et al. Therefore we see microservices as an architecture "[...] to describe a particular way of designing software applications as suites of independently deployable services." Reliable In-Field Tests for Testable Microservices of Process Control Systems Authors: Joachim Fröhlich; Christoph Stückjürgen Paper Abstract Microservices for process control systems differ from microservices for information systems. Testing of microservices is particularly crucial in industrial contexts due to the interaction of process control software and physical processes. Data probes permanently built into microservices enable reliable results from tests (probe programs) about the behavior of single and multiple microservices, even under rough and uncomfortable operating conditions in close proximity to controlled physical processes. The Elixir programming language: Reliable microservices made easy Author: Adam Kuffel Paper Abstract The talk will explain and demonstrate Elixir concepts using power-point slides and live coding demos. Depending on the available time, some topics might be done in a larger extent than others. Topics covering the distribution and communication of nodes will have priority, as they show the suitability of Elixir for microservices. Due to the easily understandable syntax of Elixir, it should be possible to follow the code examples without knowing the language in detail. Bigraphical models for Container-based Systems Authors: Marino Miculan; Fabio Burco Paper Abstract Slides In microservices architectures, containers play a central role, because they provide development, packaging and deployment mechanisms, such that developers can focus on the logic and dependencies of applications, while system administrators can focus on deployment and management issue. In this work, we propose a formal model for container-based systems, using the framework of Bigraphical Reactive Systems (BRSs). We first introduce local directed bigraphs, a variant of directed bigraphs which allows to deal with localized resources. Then, we define the signature for containers, and some examples. It turns out that the composition of containers (as in docker-compose or kubectl) corresponds precisely to the composition of the corresponding bigraphs inside a specific environment bigraph, which corresponds to the YAML file used to describe the composition of containers. The resulting bigraphic objects can be analysed and manipulated, using techniques from graph theory. In fact, properties about containers can be formalized as properties of the corresponding bigraphic representations Chair: Fabrizio Montesi Location: Room F.211
12:10 12:50	Lunch Location: Room F.212
13:00 14:00	Engineering Reliability Speaker: Ramón Medrano Llamas Slides Abstract of the keynote Chair: Marco Peressotti Location: Room F.211
14:00 14:20	Mayor's Address Mayor of Dortmund: Ullrich Sierau Address of the mayor of Dortmund to the Microservices Community on current and future projects to lead the process of Digital Transformation in the Ruhr area Chairs: Fabrizio Montesi, Sabine Sachweh Location: Room F.211
14:20 15:10	Applications 1 Microservices in Higher Education - Migrating a Legacy Insurance Core Application Authors: Andreas Hausotter; Arne Koschel; Moritz Lange Paper Abstract Slides The bachelor's program in Applied Computer Science of the Univ. of Applied Sciences and Arts, Hannover, comprises a practical project of two semesters, where students have to apply the competencies and project management skills acquired in previous courses. The project "Potential and Challenges of Microservices in the Insurance Industry" was carried out with two partner companies. During the winter semester 2017 the basics of microservices have been worked out, technologies were selected and applied to a demo scenario. Results have been presented to and discussed with the partners. The following semester focused on the migration of a monolithic mainframe-based core application, namely the "Partner Management System (PMS)", whereby only functional requirements were specifed by the companies. The students task was to design the functional and technical concept and the implementation of a prototype based on the selected technology stack. The aim was to prove the suitability of the microservices approach for the insurance industry. In addition, known benefts of the microservices architecture should be highlighted and challenges and limitations addressed. Flow Studio - An online flow-based programming environment for domain-specific microservice applications Authors: Marcel Hahn; Albert Zündorf Paper Abstract Slides The introduction of microservice architectures in companies often increases the complexity of the already heterogeneous IT landscape. There are even more independent applications and the relevant information is even more distributed. In addition, the IT departments are usually busy and a new requirement from the specialist departments cannot be implemented fast enough. This paper introduces a tool that enables domain experts to create complex data flow-based applications across multiple microservices without programming. Chair: Balint Maschio Location: Room F.211
15:10 15:30	Coffee Break Location: Room F.212
15:30 16:20	Applications 2 Microservice-Oriented Computing for the Internet of Things Authors: Maurizio Gabbrielli; Ivan Lanese; Stefano Pio Zingaro Paper Abstract Slides We present a language-based approach tackling the problem of IoT integration. The approach is based on the use of the microservice-oriented programming language Jolie, that we extended to support IoT protocols such as coap and mqtt. Ephemeral Data Handling in Microservices Authors: Fabrizio Montesi; Larisa Safina; Stefano Pio Zingaro Paper Abstract Slides We present a framework in the Jolie programming language for ephemeral data handling in microservices; the building blocks of software for modern Large-scale systems that, due to regulations (GDPR) and other constraints (e.g., IoT and Edge Computing) need to handle data in an ephemeral way. Our framework includes a query language and an execution engine, that we formalised instantiating a sound version of the MongoDB query language. In our presentation we will illustrate the features of our framework through a non-trivial eHealth use case, which describes the handling of the data and the workflow of a diagnostic algorithm. Chair: Jonas Sorgalla Location: Room F.211
16:20 17:00	Short talks Updating the current Jolie microservices based DMS solution to include electronic invoicing Author: Balint Maschio Paper Abstract Slides This paper looks at the evolution of the a DMS solution to include the new electronic invoice. Request Log API Pattern - An architecture pattern for a better logging and easy testing of microservices Authors: Marcel Hahn; Albert Zündorf Paper Abstract Slides The practical testing of a microservice is still a big challenge. This paper introduces a special microservice logging API as an architecture pattern that can be used to retrieve additional debug information for each request. This additional information can be used for unit testing and improved logging of microservices. Chair: Philipp Heisig Location: Room F.211

February 21st (Theme: Microservice Deployment & Experiences)

8:00	Registration desk open Location: Room F.212
9:00 10:00	Factory of Things - Using Microservices for Data Processing and IoT Speaker: Jörn Esdohr Abstract of the keynote Chair: Florian Rademacher Location: Room F.211
10:00 10:20	Coffee Break Location: Room F.212
10:30 12:10	Deployment Automation Co-Design of Business and IT Services Author: Blagovesta Pirelli Paper Abstract Slides In this talk, we will present our model-driven method for design of business and IT services. The talk is based on a work-in-progress project for business-IT alignment extension of SEAM, an existing service-design method. We will present how to specify the interface of a REST API based on the business services that use it. We will also present our results and tools and conclude with future directions for our work. Beyond auto-scaling: application-aware optimal elasticity Authors: Jacopo Mauro; Iacopo Talevi; Gianluigi Zavattaro Paper Abstract Slides Microservices recently gained popularity as an architectural style that, inspired by service-oriented computing, structures software applications as compositions of fine-grained and loosely-coupled services. This approach is intended to increase the modularity and scalability of applications. For this reason, modern software engineering practices, like continuous delivery/deployment and autoscaling have microservices at their base. In this extended abstract we discuss limitations of the autoscaling technique, which is based on the addition/removal of new microservice replicas depending on some specific local metrics. As an alternative, we propose a scaling approach that works at the global level, by adding replicas of several microservices at the same time. In this way we support the computation of globally optimal scaling plans in which instances of different microservices could be deployed on the same node. PREvant (Preview Servant): Composing Microservices into Reviewable and Testable Applications Author: Marc Schreiber Paper Abstract Slides This paper introduces "PREvant" (preview servant), a software tool which provides a simple RESTful API for deploying and composing containerized microservices as reviewable applications. PREvant’s API serves as a connector between the continuous delivery pipelines of all involved microservices and the infrastructure that hosts the applications. A Jolie based platform for speeding-up the digitalization of system integration processes Authors: Claudio Guidi; Balint Maschio Paper Abstract Slides In this paper we intend to show how microservices architectures approached from a linguistic point of view can dramatically reduce costs in the development and maintenance of system integration solutions. We will provide support to our thesis by showing a real and concrete scenario in a production environment where we pervasively used the programming language Jolie for implementing system integration solution. Moreover, we will show some basic features provided by a Jolie based platform called Jung which can further accelerate the development and the maintenance of the discussed solutions. Chairs: Marcel Hahn, Sebastian Copei Location: Room F.211
12:10 13:10	Lunch Location: Room F.212
13:20 14:20	Build Fashionable Container Systems with Microservices, Clouds, and Kubernetes Speaker: Peter Rossbach Abstract of the keynote Chair: Florian Rademacher Location: Room F.211
14:20 15:10	Experiences 1 Moving mountains – practical approaches for moving monolithic applications to Microservices Authors: Nhiem Lu; Gert Glatz; Dennis Peuser Paper Abstract The advent of Microservice Architecture led to a rethinking of legacy systems in many organizations. While Microservices provide numerous advantages, several challenges must be faced to migrate a monolith application, in terms of technical, processual and human aspects. Using industry examples, best practice approaches will be identified for a successful move from a monolith to Microservices. Microservices in the German Industry: Insights into Technologies, Characteristics, and Software Quality Authors: Jonas Fritzsch; Justus Bogner; Stefan Wagner; Alfred Zimmermann Paper Abstract Slides While Microservices initially were a topic mainly driven by practitioners, they currently are heavily researched in academia. In this paper, we contribute a qualitative study with the goal to provide insights into industry adoption and implementation of Microservices. During 17 in-depth interviews with software professionals from 10 companies we analyzed 14 service-based systems. The interviews focused on applied technologies, adherence to Microservice characteristics, and the perceived influence on software quality. We summarize the most important take-aways along with insights into common practices of companies across different domains and sizes. Researchers may build upon our findings and take them into account when designing industry-focused methods or techniques. This extended abstract includes some figures and excerpts from a forthcoming publication of the authors. Chair: Larisa Safina Location: Room F.211
15:10 15:30	Coffee Break Location: Room F.212
15:30 17:00	Experiences 2 A Microservice architecture for monitoring, processing and predicting climate data in animal husbandry Authors: Alexander Stein; Marcel Zillekens; Marius Khan Paper Abstract Slides In this work we present a microservice architecture that offers a reliable and scalable system to monitor and process incoming climate data from sensors of hog houses. Through data processing our system predicts trends about long term climate data. By using machine learning algorithms and based on the trends, the system recommends parameter values for climate computers installed in hog houses. %The data processing gives our system the capability to extract predictions about the long term climate trend to generate recommendation values for locally installed climate computers by using machine learning algorithms. Experience Report: First Steps towards a Microservice Architecture for Virtual Power Plants in the Energy Sector Authors: Manuel Wickert; Sven Liebehentze; Albert Zündorf Paper Abstract Virtual Power Plants (VPPs) are a concept for providing energy services by aggregating decentralized energy resources (DERs) to provide stakeholders in the energy sector an abstraction over many small resources. The supporting software systems are operated as a part of the critical infrastructure and have to deal with a fast growing number of DERs. Therefore, modern architectures like Microservice architectures can be a good choice for dealing with such scalable systems where changing requirements from market and regulation is daily business. In this report, we outline our first experiences of changing an existing VPP software system to a Microservice architecture. Chair: Stefano Pio Zingaro Location: Room F.211