Adapting Component-based Systems at Runtime via Policies with Temporal Patterns

International audienceDynamic reconfiguration allows adding or removing components of component-based systems without incurring any system downtime. To satisfy specific requirements, adaptation policies provide the means to dynamically reconfigure the systems in relation to (events in) their environment. This paper extends event-based adaptation policies by integrating temporal requirements into them. The challenge is to reconfigure component-based systems at runtime while considering both their functional and non-functional requirements. We illustrate our theoretical contributions with an example of an autonomous vehicle location system. An implementation using the Fractal component model constitutes a practical contribution. It enables dynamic reconfigurations guided by either enforcement or reflection adaptation policies

High-level Language Support for the Control of Reconfigurations in Component-based Architectures

International audienceNowadays, smart home is extended beyond the house itself to encompass connected platforms on the Cloud as well as mobile personal devices. This Smart Home Extended Architecture (SHEA) helps customers to remain in touch with their home everywhere and any time. The endless increase of connected devices in the home and outside within the SHEA multiplies the deployment possibilities for any application. Therefore, SHEA should be taken from now as the actual target platform for smart home application deployment. Every home is different and applications offer different services according to customer preferences. To manage this variability, we extend the feature modeling from software product line domain with deployment constraints and we present an example of a model that could address this deployment challenge

Реконфигурирование компонентно-ориентированных систем на базе графовых грамматик

Dynamic reconfigurations can modify the architecture of component-based systems without incurring any system downtime. In this context, the main contribution of the present article is the establishment of correctness results proving component-based systems reconfigurations using graph grammars. New guarded reconfigurations allow us to build reconfigurations based on primitive reconfiguration operations using sequences of reconfigurations and the alternative and the repetitive constructs, while preserving configuration consistency. A practical contribution consists of the implementation of a component-based model using the GROOVE graph transformation tool. Then, after enriching the model with interpreted configurations and reconfigurations in a consistency compatible manner, a simulation relation is exploited to validate component systems’ implementations. This sound implementation is illustrated on a cloud-based multitier application hosting environment managed as a component-based system.Динамические реконфигурирования могут изменять архитектуру компонентно-ориентированных систем, не подвергаясь никакому системному простою. В этом контексте основной вклад данной статьи – доказательство результатов корректности реконфигурирования систем, используя графовые грамматики. В этой статье предложены новые охраняемые реконфигурирования на базе логики Хоара, которые построены на основе примитивных операций по реконфигурированию и включают последовательности реконфигурирований, альтернативные и повторяющиеся конструкции, сохраняя при этом непротиворечивость конфигураций. Практический вклад состоит в описании имплементации компонентно-ориентированной модели, используя программный инструмент GROOVE для преобразования графов. После обогащения модели интерпретированными конфигурациями и реконфигурированиями, совместимого с непротиворечивостью, отношение симуляции используется для доказательства корректности имплементации, выполненной под GROOVE. Эта имплементация иллюстрирована на примере многоуровневого облачно-ориентированного приложения

Behavioural Model-based Control for Autonomic Software Components

International audienceAutonomic Managers (AMs) have been largely used to autonomously control reconfigurations within software compo- nents. This management is performed based on past monitoring events, configurations as well as behavioural programs defining the adaptation logics and invariant properties. The challenge here is to provide assurances on navigation through the configuration space, which requires taking decisions that involve predictions on possible futures of the system. This paper proposes the design of AMs based on logical discrete control approaches, where the use of behavioural models enriches the manager with a knowledge not only on events, states and past history, but also with possible future configurations. We define a Domain Specific Language, named Ctrl-F, which provides high-level constructs to describe behavioural programs in the context of software components. The formal definition of Ctrl-F is given by translation to Finite State Automata, which allow for the exploration of behavioural programs by verification or Discrete Controller Synthesis, automatically generating a controller enforcing correct behaviours. We implement an AM by integrating the result of Ctrl-F compilation and validate it with an adaptation scenario over Znn.com, a self-adaptive case study

Concurrency-preserving and sound monitoring of multi-threaded component-based systems: theory, algorithms, implementation, and evaluation

International audienceThis paper addresses the monitoring of logic-independent linear-time user-provided properties in multi-threaded component-based systems. We consider intrinsically independent components that can be executed concurrently with a centralized coordination for multiparty interactions. In this context, the problem that arises is that a global state of the system is not available to the monitor. A naive solution to this problem would be to plug in a monitor which would force the system to synchronize in order to obtain the sequence of global states at runtime. Such a solution would defeat the whole purpose of having concurrent components. Instead, we reconstruct on-the-fly the global states by accumulating the partial states traversed by the system at runtime. We define transformations of components that preserve their semantics and con-currency and, at the same time, allow to monitor global-state properties. Moreover, we present RVMT-BIP, a prototype tool implementing the transformations for monitoring multi-threaded systems described in the BIP (Behavior, Interaction, Priority) framework, an expressive framework for the formal construction of heterogeneous systems. Our experiments on several multi-threaded BIP systems show that RVMT-BIP induces a cheap runtime overhead