Microservice architectures are an emergent service-oriented paradigm widely used in industry to develop and deploy scalable software systems. The underlying idea is to design highly independent services that implement small units of functionality and can interact with each other through lightweight interfaces. Even though microservices are often used with success, their design and maintenance pose novel challenges to software engineers. In particular, it is questionable whether the intended independence of microservices can actually be achieved in practice. So, it is important to understand how and why microservices evolve during a system’s life-cycle, for instance, to scope refactorings and improvements of a system’s architecture or to develop supporting tools. To provide insights into how microservices evolve, we report a large-scale empirical study on the (co-)evolution of microservices in 11 open-source systems, involving quantitative and qualitative analyses of 7,319 commits. Our quantitative results show that there are recurring patterns of (co-)evolution across all systems, for instance, “shotgun surgery” commits and microservices that are largely independent, evolve in tuples, or are evolved in almost all changes. We refine our results by analyzing service-evolving commits qualitatively to explore the (in-)dependence of microservices and the causes for their specific evolution. The contributions in this article provide an understanding for practitioners and researchers on how microservices evolve in what way, and how microservice-based systems may be improved.

Abstract The microservices architecture (MSA) style has been gaining interest in recent years because of its high scalability, ability to be deployed in the cloud, and suitability for DevOps practices. While new applications can adopt MSA from their inception, many legacy monolithic systems must be migrated to an MSA to benefit from the advantages of this architectural style. To support the migration process, we propose MicroMiner, a microservices identification approach that is based on static‐relationship analyses between code elements as well as semantic analyses of the source code. Our approach relies on machine learning (ML) techniques and uses service types to guide the identification of microservices from legacy monolithic systems. We evaluate the efficiency of our approach on four systems and compare our results to ground‐truths and to those of two state‐of‐the‐art approaches. We perform a qualitative evaluation of the resulted microservices by analyzing the business capabilities of the identified microservices. Also a quantitative analysis using the state‐of‐the‐art metrics on independence of functionality and modularity of services was conducted. Our results show the effectiveness of our approach to automate one of the most time‐consuming steps in the migration of legacy systems to microservices. The proposed approach identifies architecturally significant microservices with a 68.15% precision and 77% recall.

To succeed with the development of modern software, organizations must have the agility to adapt faster to constantly evolving environments to deliver more reliable and optimized solutions that can be adapted to the needs and environments of their stakeholders including users, customers, business, development, and IT. However, stakeholders do not have sufficient automated support for global decision making, considering the increasing variability of the solution space, the frequent lack of explicit representation of its associated variability and decision points, and the uncertainty of the impact of decisions on stakeholders and the solution space. This leads to an ad-hoc decision making process that is slow, error-prone, and often favors local knowledge over global, organization-wide objectives. The Multi-Plane Models and Data (MP-MODA) framework explicitly represents and manages variability, impacts, and decision points. It enables automation and tool support in aid of a multi-criteria decision making process involving different stakeholders within a feedback-driven software development process where feedback cycles aim to reduce uncertainty. We present the conceptual structure of the framework, discuss its potential benefits, and enumerate key challenges related to tool supported automation and analysis within MP-MODA.

Traditional requirements engineering does not benefit from modern software development techniques. The goal of this tutorial is to revisit requirements elicitation and to bridge the gap between traditional requirements engineering and modern software development. This tutorial will provide the attendees with concrete and immediately applicable guidance by demonstrating how to operationalize a fully-fledged toolchain going from user stories to automated acceptance testing using open-source tools.

Embedded systems, like those found in the automotive domain, must comply with stringent functional and non-functional requirements. To fulfil these requirements, engineers are confronted with a plethora of design alternatives both at the software and hardware level, out of which they must select the optimal solution wrt. possibly-antagonistic quality attributes (e.g. cost of manufacturing vs. speed of execution). We propose a model-driven framework to assist engineers in this choice. It captures high-level specifications of the system in the form of variable dataflows and configurable hardware platforms. A mapping algorithm then derives the design space, i.e. the set of compatible pairs of application and platform variants, and a variability-aware executable model, which encodes the functional and non-functional behaviour of all viable system variants. Novel verification algorithms then pinpoint the optimal system variants efficiently. The benefits of our approach are evaluated through a real-world case study from the automotive industry.

Abstract Large‐scale corrective and perfective maintenance is often automated thanks to rewriting rules using tools such as Python2to3, Spoon, or Coccinelle. Such tools consider these rules as black‐boxes and compose multiple rules by chaining them: giving the output of a given rewriting rule as input to the next one. It is up to the developer to identify the right order (if it exists) among all the different rules to yield the right program. In this paper, we define a formal model compatible with the black‐box assumption that reifies the modifications (Δs) made by each rule. Leveraging these Δs, we propose a way to safely compose multiple rules when applied to the same program by (a) ensuring the isolated application of the different rules and (b) identifying unexpected behaviors that were silently ignored before. We assess this approach on two large‐scale case studies: (a) identifying conflicts in the Linux source‐code automated maintenance and (b) fixing energy antipatterns existing in Android applications available on GitHub.

Although Model-Based Software Engineering (MBE) is a widely accepted Software Engineering (SE) discipline, no agreed-upon core set of concepts and practices (i.e., a Body of Knowledge) has been defined for it yet. With the goals of characterizing the contents of the MBE discipline, promoting a global consistent view of it, clarifying its scope with regard to other SE disciplines, and defining a foundation for the development of educational curricula on MBE, this paper proposes the contents for a Body of Knowledge for MBE. We also describe the methodology that we have used to come up with the proposed list of contents, as well as the results of a survey study that we conducted to sound out the opinion of the community on the importance of the proposed topics and their level of coverage in the existing SE curricula.

The RE'18 theme is: "Crossing Boundaries and Increasing Impact". In this context we propose a tutorial on Requirements in an Agile context that aims at exploring the boundaries between requirements, specifications, stories, scenarios and tests. It follows the recent work started in the RE community about agility, from a practical point of view.

Smart buildings and smart cities rely on interconnected sensor networks that collect data about their environment to support various applications. Developing and deploying the data collection architectures of these systems is a challenging problem. The specificities of the sensor platforms compel software engineers to work at a low level. This makes this activity tedious, producing code that badly exploits the network architecture, and hampering reuse of data collection policies. Moreover, several data collection programs cannot be guaranteed to be deployable on a shared infrastructure. In this paper, we present an automated approach that supports (i) the definition of data collection policies at a higher level of abstraction, (ii) the representation of the diverse platforms and the network topology, and (iii) the automatic composition and deployment of the policies on top of heterogeneous sensing infrastructures following different strategies. The approach is tooled and has been assessed on both realistic and simulated deployments.

In Software Product Line (SPL) engineering, Feature Models (FMs) are widely used to capture and manage variability in a sound and organized fashion. Though semantics, notations and reasoning support are well established, maintaining large FMs is still an open problem. As large FMs naturally contain different concerns, some related to domains, others being inherently cross-cutting ones, it is challenging to find a decomposition that will tame this complexity and ease maintenance. This paper presents a visual representation of dependent FMs useful in decomposing a large FM while quantitatively visualizing constraints between and inside them. This Variability Blueprint is intuitive enough to enable the SPL maintainer to confine dependencies between FMs in a small set of identified features inside each decomposed FM. We describe our blueprint and report on its application on two case studies.

The Internet of Things (IoT) relies on physical objects interconnected between each others, creating a mesh of devices producing information. In this context, sensors are surrounding our environment (e.g., cars, buildings, smartphones) and continuously collect data about our living environment. Thus, the IoT is a prototypical example of Big Data. The contribution of this paper is to define a software architecture supporting the collection of sensor-based data in the context of the IoT. The architecture goes from the physical dimension of sensors to the storage of data in a cloud-based system. It supports Big Data research effort as its instantiation supports a user while collecting data from the IoT for experimental or production purposes. The results are instantiated and validated on a project named SMARTCAMPUS, which aims to equip the SophiaTech campus with sensors to build innovative applications that supports end-users.

Cloud computing is emerging as a major trend in the ICT industry. While most of the attention of the research community is focused on considering the perspective of the Cloud providers, offering mechanisms to support scaling of resources and interoperability and federation between Clouds, the perspective of developers and operators willing to choose the Cloud without being strictly bound to a specific solution is mostly neglected. We argue that Model-Driven Development can be helpful in this context as it would allow developers to design software systems in a cloud-agnostic way and to be supported by model transformation techniques into the process of instantiating the system into specific, possibly, multiple Clouds. The MODAClouds (MOdel-Driven Approach for the design and execution of applications on multiple Clouds) approach we present here is based on these principles and aims at supporting system developers and operators in exploiting multiple Clouds for the same system and in migrating (part of) their systems from Cloud to Cloud as needed. MODAClouds offers a quality-driven design, development and operation method and features a Decision Support System to enable risk analysis for the selection of Cloud providers and for the evaluation of the Cloud adoption impact on internal business processes. Furthermore, MODAClouds offers a run-time environment for observing the system under execution and for enabling a feedback loop with the design environment. This allows system developers to react to performance fluctuations and to re-deploy applications on different Clouds on the long term.

Web Services Oriented Architecture (WSOA) supports development of high quality applications based on a control--flow between services. The introduction of a loop to deal with a dataset inside an orchestration is a typical evolution use case inside a WSOA, but there is no tool support to perform such refactoring operation. In this paper we propose a new method to refactor an orchestration dealing with a variable v so that it iterates over a dataset v* automatically. This algorithm is then validated on a running software used as a validation platform by the French research project called FAROS.