Runtime variability for dynamic reconfiguration in wireless sensor network product lines

Runtime variability is a key technique for the success of Dynamic Software Product Lines (DSPLs), as certain application demand reconfiguration of system features and execution plans at runtime. In this emerging research work we address the problem of dynamic changes in feature models in sensor networks product families, where nodes of the network demand dynamic reconfiguration at post-deployment time

Unified GUI adaptation in Dynamic Software Product Lines

In the modern world of mobile computing and ubiquitous technology, society is able to interact with technology in new and fascinating ways. To help provide an improved user experience, mobile software should be able to adapt itself to suit the user. By monitoring context information based on the environment and user, the application can better meet the dynamic requirements of the user. Similarly, it is noticeable that programs can require different static changes to suit static requirements. This program commonality and variability can benefit from the use of Software Product Line Engineering, reusing artefacts over a set of similar programs, called a Software Product Line (SPL). Historically, SPLs are limited to handling static compile time adaptations. Dynamic Software Product Lines (DSPL) however, allow for the program configuration to change at runtime, allow for compile time and runtime adaptation to be developed in a single unified approach. While currently DSPLs provide methods for dealing with program logic adaptations, variability in the Graphical User Interface (GUI) has largely been neglected. Due to this, depending on the intended time to apply GUI adaptation, different approaches are required. The main goal of this work is to extend a unified representation of variability to the GUI, whereby GUI adaptation can be applied at compile time and at runtime. In this thesis, an approach to handling GUI adaptation within DSPLs, providing a unified representation of GUI variability is presented. The approach is based on Feature-Oriented Programming (FOP), enabling developers to implement GUI adaptation along with program logic in feature modules. This approach is applied to Document-Oriented GUIs, also known as GUI description languages. In addition to GUI unification, we present an approach to unifying context and feature modelling, and handling context dynamically at runtime, as features of the DSPL. This unification can allow for more dynamic and self-aware context acquisition. To validate our approach, we implemented tool support and middleware prototypes. These different artefacts are then tested using a combination of scenarios and scalability tests. This combination first helps demonstrate the versatility and its relevance of the different approach aspects. It further brings insight into how the approach scales with DSPL size

Uma solução de implantação auto-adaptativa para plataformas Android

Orientador: Cecília Mary Fischer RubiraDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de ComputaçãoResumo: Os dispositivos móveis, hoje em dia, fornecem recursos semelhantes aos de um computador pessoal de uma década atrás, permitindo o desenvolvimento de aplicações complexas. Consequentemente, essas aplicações móveis podem exigir tolerar falhas em tempo de execução. No entanto, a maioria das aplicações móveis de hoje são implantados usando configurações estáticas, tornando difícil tolerar falhas durante a sua execução. Nós propomos uma infraestrutura de implantação auto-adaptativa para lidar com este problema. A nossa solução oferece um circuito autônomo que administra o modelo de configuração atual da aplicação usando um modelo de características dinâmico associado com o modelo arquitetônico da mesma. Em tempo de execução, de acordo com a seleção dinâmica de características, o modelo arquitetônico implantado na plataforma se re-configura para fornecer uma nova solução. Uma aplicação Android foi implementada utilizando a solução proposta, e durante sua execução, a disponibilidade de serviços foi alterada, de tal forma que sua configuração corrente foi dinamicamente alterada para tolerar a indisponibilidade dos serviçosAbstract: Mobile devices, nowadays, provide similar capabilities as a personal computer of a decade ago, allowing the development of complex applications. Consequently, these mobile applications may require tolerating failures at runtime. However, most of the today¿s mobile applications are deployed using static configurations, making difficult to tolerate failure during their execution. We propose an adaptive deployment infrastructure to deal with this problem. Our solution offers an autonomic loop that manages the current configuration model of the application using a dynamic feature model associated with the architectural model. During runtime, according to the dynamic feature selection, the deployed architectural model can be modified to provide a new deployment solution. An Android application was implemented using the proposed solution, and during its execution, the services availability was altered so that its current configuration was changed dynamically in order to tolerate the unavailability of servicesMestradoCiência da ComputaçãoMestre em Ciência da Computação131830/2013-9CNP

Realising Variability in Dynamic Software Product Line Solutions

Modern systems need to be able to self-adapt to changes in user needs, and changes affecting the system itself or its environment. Dynamic software product line (DSPL) is an engineering approach for developing self-adaptive systems based on commonalities and variabilities for a family of similar systems. Currently, many DSPL approaches fail to meet all adaptability requirements, and in many cases, they are developed in a such unstructured manner that the controller is not explicitly represented, for example. We specify a two-dimension taxonomy to address basic technical issues for realising variability in DSPLs. The self-adaptation dimension classifies the different design choices for the adaptability requirements. The DSPL variability dimension classifies different design choices for implementing variability schemes and for creating different kinds of feature models. Our study was substantiated by surveying several DSPL approaches, and evaluating and comparing their different design strategies. We also summarise practical issues and difficulties, identify major trends in actual DSPL proposals, and suggest directions for future

A Decision Support System for Selecting Between Designs for Dynamic Software Product Lines

When commissioning a system, a myriad of potential designs can successfully fulfill the system\u27s goals. Deciding among the candidate designs requires an understanding of how the design affects the system\u27s quality attributes and how much effort is needed to realize the design. The difficulty of the process compounds if the system to be designed includes dynamic run-time self- adaptivity, the ability for the system to self-modify its architecture at run-time in response to either external or internal stimuli, as the type and location of the dynamic self-adaptivity within the architecture must be co-decided. In this proposal, we introduce a Decision Support System, which contains a new Dynamic Software Product Line-centric cost / effort estimation technique, the Structured Intuitive Model for Dynamic Adaptive System Economics (SIMDASE), that will allow system designers / architects to select the most appropriate design for systems where the candidates can be structured as a Dynamic Software Product Line. We will focus on using the Decision Support System to select designs for a system where at least one component of the system is a low-level embedded system for use within the Internet of Things (IoT), particularly embedded systems whose purpose is to exist as things (either intelligent sensors or actuators). The Decision Support System we introduce is a multi-step process that begins with a high- level system architecture generated from the system requirements and goals. Candidate designs that can fulfill all goals / requirements of the high-level architecture are selected. Each design is then annotated using SIMDASE so that the effort, risk, cost and return on investment that can be expected from the realization of the design(s) can be compared in order to select the best design for a given organization

Representing Variability in Software Architecture: A Systematic Literature Review

Variability in software - intensive systems is the ability of a software artefact (e.g., a system, subsystem, or component) to be extended, customised or configured for deployment in a specific context. Software Architecture is a high - level description of a software - intensive system that abstracts the system implementation details allowing the architect to view the system as a whole. Although variability in software architecture is recognised as a challenge in multiple domains, there has been no formal consensus on how variability should be captured or represented. The objective of this research was to provide a snapshot of the state - of - the - art on representing variability in software architecture while assessing the nature of the different approaches. To achieve this objective, a Systematic Literature Review (SLR) was conducted covering literature produced from January 1991 until June 2016. Then, grounded theory was used to conduct the analysis and draw conclusions from data, mini mising threats to validity. In this paper , we report on the findings from the study

Run-time Variability with Roles

Adaptability is an intrinsic property of software systems that require adaptation to cope with dynamically changing environments. Achieving adaptability is challenging. Variability is a key solution as it enables a software system to change its behavior which corresponds to a specific need. The abstraction of variability is to manage variants, which are dynamic parts to be composed to the base system. Run-time variability realizes these variant compositions dynamically at run time to enable adaptation. Adaptation, relying on variants specified at build time, is called anticipated adaptation, which allows the system behavior to change with respect to a set of predefined execution environments. This implies the inability to solve practical problems in which the execution environment is not completely fixed and often unknown until run time. Enabling unanticipated adaptation, which allows variants to be dynamically added at run time, alleviates this inability, but it holds several implications yielding system instability such as inconsistency and run-time failures. Adaptation should be performed only when a system reaches a consistent state to avoid inconsistency. Inconsistency is an effect of adaptation happening when the system changes the state and behavior while a series of methods is still invoking. A software bug is another source of system instability. It often appears in a variant composition and is brought to the system during adaptation. The problem is even more critical for unanticipated adaptation as the system has no prior knowledge of the new variants. This dissertation aims to achieve anticipated and unanticipated adaptation. In achieving adaptation, the issues of inconsistency and software failures, which may happen as a consequence of run-time adaptation, are evidently addressed as well. Roles encapsulate dynamic behavior used to adapt players representing the base system, which is the rationale to select roles as the software system's variants. Based on the role concept, this dissertation presents three mechanisms to comprehensively address adaptation. First, a dynamic instance binding mechanism is proposed to loosely bind players and roles. Dynamic binding of roles enables anticipated and unanticipated adaptation. Second, an object-level tranquility mechanism is proposed to avoid inconsistency by allowing a player object to adapt only when its consistent state is reached. Last, a rollback recovery mechanism is proposed as a proactive mechanism to embrace and handle failures resulting from a defective composition of variants. A checkpoint of a system configuration is created before adaptation. If a specialized bug sensor detects a failure, the system rolls back to the most recent checkpoint. These mechanisms are integrated into a role-based runtime, called LyRT. LyRT was validated with three case studies to demonstrate the practical feasibility. This validation showed that LyRT is more advanced than the existing variability approaches with respect to adaptation due to its consistency control and failure handling. Besides, several benchmarks were set up to quantify the overhead of LyRT concerning the execution time of adaptation. The results revealed that the overhead introduced to achieve anticipated and unanticipated adaptation to be small enough for practical use in adaptive software systems. Thus, LyRT is suitable for adaptive software systems that frequently require the adaptation of large sets of objects

Une approche basée sur les lignes de produits logiciels pour la configuration et adaptation des environments multi-nuages

Cloud computing is characterized by a model in which computing resources are delivered as services in a pay-as-you-go manner, which eliminates the need for upfront investments, reducing the time to market and opportunity costs. Despite its benefits, cloud computing brought new concerns about provider dependence and data confidentiality, which further led to a growing trend on consuming resources from multiple clouds. However, building multi-cloud systems is still very challenging and time consuming due to the heterogeneity across cloud providers' offerings and the high-variability in the configuration of cloud providers. This variability is expressed by the large number of available services and the many different ways in which they can be combined and configured. In order to ensure correct setup of a multi-cloud environment, developers must be aware of service offerings and configuration options from multiple cloud providers.To tackle this problem, this thesis proposes a software product line-based approach for managing the variability in cloud environments in order to automate the setup and adaptation of multi-cloud environments. The contributions of this thesis enable to automatically generate a configuration or reconfiguration plan for a multi-cloud environment from a description of its requirements. The conducted experiments aim to assess the impact of the approach on the automated analysis of feature models and the feasibility of the approach to automate the setup and adaptation of multi-cloud environments.Le cloud computing est caractérisé par un modèle dans lequel les ressources informatiques sont fournies en tant qu'un service d'utilité, ce qui élimine le besoin de grands investissements initiaux. Malgré ses avantages, le cloud computing a suscité de nouvelles inquiétudes concernant la dépendance des fournisseurs et la confidentialité des données, ce qui a conduit à l'émergence des approches multi-cloud. Cependant, la construction de systèmes multi-cloud est toujours difficile en raison de l'hétérogénéité entre les offres des fournisseurs de cloud et de la grande variabilité dans la configuration des fournisseurs de cloud. Cette variabilité est caractérisé par le grand nombre de services disponibles et les nombreuses façons différentes de les combiner et de les configurer. Afin de garantir la configuration correcte d'un environnement multi-cloud, les développeurs doivent connaître les offres de services et les options de configuration de plusieurs fournisseurs de cloud.Pour traiter ce problème, cette thèse propose une approche basée sur les lignes de produits logiciels pour gérer la variabilité dans les cloud afin d'automatiser la configuration et l'adaptation des environnements multi-cloud. Les contributions de cette thèse permettent de générer automatiquement un plan de configuration ou de reconfiguration pour un environnement multi-cloud à partir d'une description de ses exigences. Les expérimentations menées visent à évaluer l'impact de l'approche sur l'analyse automatisée des modèles de caractéristiques et la faisabilité de l'approche pour automatiser la configuration et l'adaptation des environnements multi-nuages