Modeling Wireless Sensor Network Architectures using AADL

International audienceRecent technological advances have enhanced the possibilities of large-scale development and commercial deployment of diverse applications using wireless sensor networks. As this development effort expands, it becomes increasingly important to build tools and formal methodologies that ease large-scale deployments of such networks. In this paper, we advocate the use of an architecture description language called AADL to describe wireless sensor network architectures. We highlight the use of component-connector paradigm of AADL in designing robust, performance-critical, real-time sensor network applications incorporating relevant dependability metrics. By careful analysis and extraction of the common requirements, we describe a case study, that of a simple data collection application using sensor networks, as a proof of concept of the AADL modeling approach. Lastly, we propose several wireless sensor network specific extensions to AADL that will further enhance the richness of such models

Early aspects: aspect-oriented requirements engineering and architecture design

This paper reports on the third Early Aspects: Aspect-Oriented Requirements Engineering and Architecture Design Workshop, which has been held in Lancaster, UK, on March 21, 2004. The workshop included a presentation session and working sessions in which the particular topics on early aspects were discussed. The primary goal of the workshop was to focus on challenges to defining methodical software development processes for aspects from early on in the software life cycle and explore the potential of proposed methods and techniques to scale up to industrial applications

A methodology for software performance modeling and its application to a border inspection system

It is essential that software systems meet their performance objectives. Many factors affect software performance and it is fundamental to identify those factors and the magnitude of their effects early in the software lifecycle to avoid costly and extensive changes to software design, implementation, or requirements. In the last decade the development of techniques and methodologies to carry out performance analysis in the early stages of the software lifecycle has gained a lot of attention within the research community. Different approaches to evaluate software performance have been developed. Each of them is characterized by a certain software specification and performance modeling notation.;In this thesis we present a methodology for predictive performance modeling and analysis of software systems. We use the Unified Modeling Language (UML) as a software modeling notation and Layered Queuing Networks (LQN) as a performance modeling notation. Our focus is on the definition of a UML to LQN transformation We extend existing approaches by applying the transformation to a different set of UML diagrams, and propose a few extensions to the current UML Profile for Schedulability, Performance, and Time , which we use to annotate UML diagrams with performance-related information. We test the applicability of our methodology to the performance evaluation of a complex software system used at border entry ports to grant or deny access to incoming travelers

Analysis as first-class citizens – an application to Architecture Description Languages

Architecture Description Languages (ADLs) support modeling and analysis of systems through models transformation and exploration. Various contributions made proposals to bring verification capabilities to designers through model-based frame- works and illustrated benefits to the overall system quality. Model-level analyses are usually performed as an exogenous, unidirectional and semantically weak transformation towards a third-party model. We claim such process can be incomplete and/or inefficient because gathered results lead to evolution of the primary model. This is particularly problematic for the design of Distributed Real-Time Embedded (DRE) systems that has to tackle many concerns like time, security or safety. In this paper, we argue why analysis should no longer be considered as a side step in the design process but, rather, should be embedded as a first-class citizen in the model itself. We review several standardized architecture description languages, which consider analysis as a goal. As an element of solution, we introduce current work on the definition of a language dedicated to the analysis of models within the scope of one particular ADL, namely the Architecture Analysis and Design Language (AADL)

Software Product Line

The Software Product Line (SPL) is an emerging methodology for developing software products. Currently, there are two hot issues in the SPL: modelling and the analysis of the SPL. Variability modelling techniques have been developed to assist engineers in dealing with the complications of variability management. The principal goal of modelling variability techniques is to configure a successful software product by managing variability in domain-engineering. In other words, a good method for modelling variability is a prerequisite for a successful SPL. On the other hand, analysis of the SPL aids the extraction of useful information from the SPL and provides a control and planning strategy mechanism for engineers or experts. In addition, the analysis of the SPL provides a clear view for users. Moreover, it ensures the accuracy of the SPL. This book presents new techniques for modelling and new methods for SPL analysis

IoT@run-time: a model-based approach to support deployment and self-adaptations in IoT systems

Today, most Internet of Things (IoT) systems leverage edge and fog computing to meet increasingly restrictive requirements and improve quality of service (QoS). Although these multi-layer architectures can improve system performance, their design is challenging because the dynamic and changing IoT environment can impact the QoS and system operation. In this thesis, we propose a modeling-based approach that addresses the limitations of existing studies to support the design, deployment, and management of self-adaptive IoT systems. We have designed a domain specific language (DSL) to specify the self-adaptive IoT system, a code generator that generates YAML manifests for the deployment of the IoT system, and a framework based on the MAPE-K loop to monitor and adapt the IoT system at runtime. Finally, we have conducted several experimental studies to validate the expressiveness and usability of the DSL and to evaluate the ability and performance of our framework to address the growth of concurrent adaptations on an IoT system.Hoy en día, la mayoría de los sistemas de internet de las cosas (IoT, por su sigla en inglés) aprovechan la computación en el borde (edge computing) y la computación en la niebla (fog computing) para cumplir requisitos cada vez más restrictivos y mejorar la calidad del servicio. Aunque estas arquitecturas multicapa pueden mejorar el rendimiento del sistema, diseñarlas supone un reto debido a que el entorno de IoT dinámico y cambiante puede afectar a la calidad del servicio y al funcionamiento del sistema. En esta tesis proponemos un enfoque basado en el modelado que aborda las limitaciones de los estudios existentes para dar soporte en el diseño, el despliegue y la gestión de sistemas de IoT autoadaptables. Hemos diseñado un lenguaje de dominio específico (DSL) para modelar el sistema de IoT autoadaptable, un generador de código que produce manifiestos YAML para el despliegue del sistema de IoT y un marco basado en el bucle MAPE-K para monitorizar y adaptar el sistema de IoT en tiempo de ejecución. Por último, hemos llevado a cabo varios estudios experimentales para validar la expresividad y usabilidad del DSL y evaluar la capacidad y el rendimiento de nuestro marco para abordar el crecimiento de las adaptaciones concurrentes en un sistema de IoT.Avui dia, la majoria dels sistemes d'internet de les coses (IoT, per la sigla en anglès) aprofiten la informàtica a la perifèria (edge computing) i la informàtica a la boira (fog computing) per complir requisits cada cop més restrictius i millorar la qualitat del servei. Tot i que aquestes arquitectures multicapa poden millorar el rendiment del sistema, dissenyar-les suposa un repte perquè l'entorn d'IoT dinàmic i canviant pot afectar la qualitat del servei i el funcionament del sistema. En aquesta tesi proposem un enfocament basat en el modelatge que aborda les limitacions dels estudis existents per donar suport al disseny, el desplegament i la gestió de sistemes d'IoT autoadaptatius. Hem dissenyat un llenguatge de domini específic (DSL) per modelar el sistema d'IoT autoadaptatiu, un generador de codi que produeix manifestos YAML per al desplegament del sistema d'IoT i un marc basat en el bucle MAPE-K per monitorar i adaptar el sistema d'IoT en temps d'execució. Finalment, hem dut a terme diversos estudis experimentals per validar l'expressivitat i la usabilitat del DSL i avaluar la capacitat i el rendiment del nostre marc per abordar el creixement de les adaptacions concurrents en un sistema d'IoT.Tecnologies de la informació i de xarxe

Adaptive Caching of Distributed Components

Die Zugriffslokalität referenzierter Daten ist eine wichtige Eigenschaft verteilter Anwendungen. Lokales Zwischenspeichern abgefragter entfernter Daten (Caching) wird vielfach bei der Entwicklung solcher Anwendungen eingesetzt, um diese Eigenschaft auszunutzen. Anschliessende Zugriffe auf diese Daten können so beschleunigt werden, indem sie aus dem lokalen Zwischenspeicher bedient werden. Gegenwärtige Middleware-Architekturen bieten dem Anwendungsprogrammierer jedoch kaum Unterstützung für diesen nicht-funktionalen Aspekt. Die vorliegende Arbeit versucht deshalb, Caching als separaten, konfigurierbaren Middleware-Dienst auszulagern. Durch die Einbindung in den Softwareentwicklungsprozess wird die frühzeitige Modellierung und spätere Wiederverwendung caching-spezifischer Metadaten gewährleistet. Zur Laufzeit kann sich das entwickelte System außerdem bezüglich der Cachebarkeit von Daten adaptiv an geändertes Nutzungsverhalten anpassen.Locality of reference is an important property of distributed applications. Caching is typically employed during the development of such applications to exploit this property by locally storing queried data: Subsequent accesses can be accelerated by serving their results immediately form the local store. Current middleware architectures however hardly support this non-functional aspect. The thesis at hand thus tries outsource caching as a separate, configurable middleware service. Integration into the software development lifecycle provides for early capturing, modeling, and later reuse of cachingrelated metadata. At runtime, the implemented system can adapt to caching access characteristics with respect to data cacheability properties, thus healing misconfigurations and optimizing itself to an appropriate configuration. Speculative prefetching of data probably queried in the immediate future complements the presented approach