References of "Barais, Olivier"
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See detailA Temporal Model for Interactive Diagnosis of Adaptive Systems
Mouline, Ludovic UL; Benelallam, Amine; Fouquet, François UL et al

in Mouline, Ludovic; Benelallam, Amine; Fouquet, François (Eds.) et al 2018 IEEE International Conference on Autonomic Computing (ICAC) (2018, September)

The evolving complexity of adaptive systems impairs our ability to deliver anomaly-free solutions. Fixing these systems require a deep understanding on the reasons behind decisions which led to faulty or ... [more ▼]

The evolving complexity of adaptive systems impairs our ability to deliver anomaly-free solutions. Fixing these systems require a deep understanding on the reasons behind decisions which led to faulty or suboptimal system states. Developers thus need diagnosis support that trace system states to the previous circumstances –targeted requirements, input context– that had resulted in these decisions. However, the lack of efficient temporal representation limits the tracing ability of current approaches. To tackle this problem, we first propose a knowledge formalism to define the concept of a decision. Second, we describe a novel temporal data model to represent, store and query decisions as well as their relationship with the knowledge (context, requirements, and actions). We validate our approach through a use case based on the smart grid at Luxembourg. We also demonstrate its scalability both in terms of execution time and consumed memory. [less ▲]

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See detailEnabling Temporal-Aware Contexts for Adaptative Distributed Systems
Mouline, Ludovic UL; Benelallam, Amine; Hartmann, Thomas UL et al

in SAC 2018: SAC 2018: Symposium on Applied Computing , April 9--13, 2018, Pau, France (2018)

Distributed adaptive systems are composed of federated entities offering remote inspection and reconfiguration abilities. This is often realized using a MAPE-K loop, which constantly evaluates system and ... [more ▼]

Distributed adaptive systems are composed of federated entities offering remote inspection and reconfiguration abilities. This is often realized using a MAPE-K loop, which constantly evaluates system and environmental parameters and derives corrective actions if necessary. The OpenStack Watcher project uses such a loop to implement resource optimization services for multi-tenant clouds. To ensure a timely reaction in the event of failures, the MAPE-K loop is executed with a high frequency. A major drawback of such reactivity is that many actions, e.g., the migration of containers in the cloud, take more time to be effective and their effects to be measurable than the MAPE-k loop execution frequency. Unfinished actions as well as their expected effects over time are not taken into consideration in MAPE-K loop processes, leading upcoming analysis phases potentially take sub-optimal actions. In this paper, we propose an extended context representation for MAPE-K loop that integrates the history of planned actions as well as their expected effects over time into the context representations. This information can then be used during the upcoming analysis and planning phases to compare measured and expected context metrics. We demonstrate on a cloud elasticity manager case study that such temporal action-aware context leads to improved reasoners while still be highly scalable. [less ▲]

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See detailRaising Time Awareness in Model-Driven Engineering
Benelallam, Amine; Hartmann, Thomas UL; Mouline, Ludovic UL et al

in 2017 ACM/IEEE 20th International Conference on Model Driven Engineering Languages and Systems (2017, September)

The conviction that big data analytics is a key for the success of modern businesses is growing deeper, and the mobilisation of companies into adopting it becomes increasingly important. Big data ... [more ▼]

The conviction that big data analytics is a key for the success of modern businesses is growing deeper, and the mobilisation of companies into adopting it becomes increasingly important. Big data integration projects enable companies to capture their relevant data, to efficiently store it, turn it into domain knowledge, and finally monetize it. In this context, historical data, also called temporal data, is becoming increasingly available and delivers means to analyse the history of applications, discover temporal patterns, and predict future trends. Despite the fact that most data that today’s applications are dealing with is inherently temporal current approaches, methodologies, and environments for developing these applications don’t provide sufficient support for handling time. We envision that Model-Driven Engineering (MDE) would be an appropriate ecosystem for a seamless and orthogonal integration of time into domain modelling and processing. In this paper, we investigate the state-of-the-art in MDE techniques and tools in order to identify the missing bricks for raising time-awareness in MDE and outline research directions in this emerging domain. [less ▲]

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See detailWeaving Rules into Models@run.time for Embedded Smart Systems
Mouline, Ludovic UL; Hartmann, Thomas UL; Fouquet, François UL et al

in Mouline, Ludovic; Hartmann, Thomas; Fouquet, François (Eds.) et al Programming '17 Companion to the first International Conference on the Art, Science and Engineering of Programming (2017, April)

Smart systems are characterised by their ability to analyse measured data in live and to react to changes according to expert rules. Therefore, such systems exploit appropriate data models together with ... [more ▼]

Smart systems are characterised by their ability to analyse measured data in live and to react to changes according to expert rules. Therefore, such systems exploit appropriate data models together with actions, triggered by domain-related conditions. The challenge at hand is that smart systems usually need to process thousands of updates to detect which rules need to be triggered, often even on restricted hardware like a Raspberry Pi. Despite various approaches have been investigated to efficiently check conditions on data models, they either assume to fit into main memory or rely on high latency persistence storage systems that severely damage the reactivity of smart systems. To tackle this challenge, we propose a novel composition process, which weaves executable rules into a data model with lazy loading abilities. We quantitatively show, on a smart building case study, that our approach can handle, at low latency, big sets of rules on top of large-scale data models on restricted hardware. [less ▲]

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See detailScapeGoat: Spotting abnormal resource usage in component-based reconfigurable software systems
Gonzalez-Herrera, Inti; Bourcier, Johann; Daubert, Erwan et al

in Journal of Systems and Software (2016)

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See detailKevoreeJS: Enabling dynamic software reconfigurations in the Browser
Tricoire, Maxime; Barais, Olivier; Leduc, Manuel et al

in WICSA/CompArch 2016 Proceedings (2016, March)

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See detailSquirrel: Architecture Driven Resource Management
Gonzalez-Herrera, Inti; Bourcier, Johan; Rudametkin, Walter et al

in 31st Annual ACM Symposium on Applied Computing (SAC'16) (2016)

Resource management is critical to guarantee Quality of Service when various stakeholders share the execution environment, such as cloud or mobile environments. In this context, providing management ... [more ▼]

Resource management is critical to guarantee Quality of Service when various stakeholders share the execution environment, such as cloud or mobile environments. In this context, providing management techniques compatible with standard practices, such as component models, is essential. Resource management is often realized through monitoring or pro- cess isolation (using virtual machines or system containers). These techniques (i) impose varying levels of overhead de- pending on the managed resource, and (ii) are applied at different abstraction levels, such as processes, threads or ob- jects. Thus, mapping components to system-level abstractions in the presence of resource management requirements can lead to sub-optimal systems. We propose Squirrel, an approach to tune component deployment and resource management in order to reduce management overhead. At run- time, Squirrel uses an architectural model annotated with resource requirements to guide the mapping of components to system abstractions, providing different resource management capabilities and overhead. We present an implementation of Squirrel, using a Java component framework, and a set of experiments to validate its feasibility and over- head. We show that choosing the right component-to-system mappings at deployment-time reduces performance penalty and/or volatile main memory use. [less ▲]

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See detailKevoree Modeling Framework (KMF): Efficient modeling techniques for runtime use
Fouquet, François UL; Nain, Grégory UL; Morin, Brice et al

Report (2014)

The creation of Domain Specific Languages(DSL) counts as one of the main goals in the field of Model-Driven Software Engineering (MDSE). The main purpose of these DSLs is to facilitate the manipulation of ... [more ▼]

The creation of Domain Specific Languages(DSL) counts as one of the main goals in the field of Model-Driven Software Engineering (MDSE). The main purpose of these DSLs is to facilitate the manipulation of domain specific concepts, by providing developers with specific tools for their domain of expertise. A natural approach to create DSLs is to reuse existing modeling standards and tools. In this area, the Eclipse Modeling Framework (EMF) has rapidly become the defacto standard in the MDSE for building Domain Specific Languages (DSL) and tools based on generative techniques. However, the use of EMF generated tools in domains like Internet of Things (IoT), Cloud Computing or Models@Runtime reaches several limitations. In this paper, we identify several properties the generated tools must comply with to be usable in other domains than desktop-based software systems. We then challenge EMF on these properties and describe our approach to overcome the limitations. Our approach, implemented in the Kevoree Modeling Framework (KMF), is finally evaluated according to the identified properties and compared to EMF. [less ▲]

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See detailA Native Versioning Concept to Support Historized Models at Runtime
Hartmann, Thomas UL; Fouquet, François UL; Nain, Grégory UL et al

in Dingel, Juergen; Schulte, Wolfram; Ramos, Isidro (Eds.) et al Model-Driven Engineering Languages and Systems - 17th International Conference, MODELS 2014, Valencia, Spain, September 28 - October 3, 2014. Proceedings (2014)

Models@run.time provides semantically rich reflection layers enabling intelligent systems to reason about themselves and their surrounding context. Most reasoning processes require not only to explore the ... [more ▼]

Models@run.time provides semantically rich reflection layers enabling intelligent systems to reason about themselves and their surrounding context. Most reasoning processes require not only to explore the current state, but also the past history to take sustainable decisions e.g. to avoid oscillating between states. Models@run.time and model-driven engineering in general lack native mechanisms to efficiently support the notion of history, and current approaches usually generate redundant data when versioning models, which reasoners need to navigate. Because of this limitation, models fail in providing suitable and sustainable abstractions to deal with domains relying on history-aware reasoning. This paper tackles this issue by considering history as a native concept for modeling foundations. Integrated, in conjunction with lazy load/storage techniques, into the Kevoree Modeling Framework, we demonstrate onto a smart grid case study, that this mechanisms enable a sustainable reasoning about massive historized models. [less ▲]

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See detailAchieving Practical Genericity in Model Weaving through Extensibility
Kramer, Max E.; Klein, Jacques UL; Steel, Jim R. H. et al

in Duddy, Keith; Kappel, Gerti (Eds.) Theory and Practice of Model Transformations (2013)

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See detailAn Eclipse Modelling Framework Alternative to Meet the Models@Runtime Requirements
Fouquet, François; Nain, Grégory UL; Morin, Brice et al

in Model Driven Engineering Languages and Systems - 15th International Conference (2012, October)

Models@Runtime aims at taming the complexity of software dynamic adaptation by pushing further the idea of reflection and considering the reflection layer as a first-class modeling space. A natural ... [more ▼]

Models@Runtime aims at taming the complexity of software dynamic adaptation by pushing further the idea of reflection and considering the reflection layer as a first-class modeling space. A natural approach to Models@Runtime is to use MDE techniques, in particular those based on the Eclipse Modeling Framework. EMF provides facilities for building DSLs and tools based on a structured data model, with tight integration with the Eclipse IDE. EMF has rapidly become the defacto standard in the MDE community and has also been adopted for building Models@Runtime platforms. For example, Frascati (implementing the Service Component Architecture standard) uses EMF for the design and runtime tooling of its architecture description language. However, EMF has primarily been thought to support design-time activities. This paper highlights specific Models@Runtime requirements, discusses the benefits and limitations of EMF in this context, and presents an alternative implementation to meet these requirements. [less ▲]

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See detailTowards Flexible Evolution of Dynamically Adaptive Systems
Perrouin, Gilles UL; Morin, Brice; Chauvel, Franck et al

in New Ideas & Emerging Results Track of the International Conference of Software Engineering (NIER@ICSE) (2012, June)

Modern software systems need to be continuously available under varying conditions. Their ability adapt to their execution context is thus increasingly seen as a key to their success. Recently, many ... [more ▼]

Modern software systems need to be continuously available under varying conditions. Their ability adapt to their execution context is thus increasingly seen as a key to their success. Recently, many approaches were proposed to design and support the execution of Dynamically Adaptive Systems (DAS). However, the ability of a DAS to evolve is limited to the addition, update or removal of adaptation rules or reconfiguration scripts. These artifacts are very specific to the control loop managing such a DAS and runtime evolution of the DAS requirements may affect other parts of the DAS. In this paper, we argue to evolve all parts of the loop. We suggest leveraging recent advances in model-driven techniques to offer an approach that supports the evolution of both systems and their adaptation capabilities. The basic idea is to consider the control loop itself as an adaptive system. [less ▲]

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See detailOn the Formalisation of GeKo: a Generic Aspect Models Weaver
Klein, Jacques UL; Kramer, Max E.; Steel, Jim R. H. et al

in On the Formalisation of GeKo: a Generic Aspect Models Weaver (Tech Report) (2012)

This technical report presents the formalisation of the composition operator of GeKo, a Generic Aspect Models Weaver

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See detailA Generic Weaver for supporting Product Lines
Morin, Brice; Klein, Jacques UL; Barais, Olivier et al

in Early Aspects Workshop at E (2008)

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See detailComposing Multi-View Aspect Models
Barais, Olivier; Klein, Jacques UL; Baudry, Benoit et al

in Abstract book of 7th IEEE International Conference on Composition Based Software Systems (2008)

Large models for complex systems can be decomposed in separate pieces corresponding to different perspectives on the system. This decomposition allows the modeller to check properties locally on some ... [more ▼]

Large models for complex systems can be decomposed in separate pieces corresponding to different perspectives on the system. This decomposition allows the modeller to check properties locally on some aspects of the system before considering the global complexity of the model. In this paper we consider two types of decomposition: according to the concerns identified in the requirements and according to structural and behavioural perspectives. Once the separate models are available and have been checked separately, they have to be composed to check global properties. In this work, we propose automatic composition operators for symmetric and asymmetric concern models, each concern being modelled from a structural and behavioural point of view. [less ▲]

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