ACME vs PDDL: support for dynamic reconfiguration of software architectures

On the one hand, ACME is a language designed in the late 90s as an interchange format for software architectures. The need for recon guration at runtime has led to extend the language with speci c support in Plastik. On the other hand, PDDL is a predicative language for the description of planning problems. It has been designed in the AI community for the International Planning Competition of the ICAPS conferences. Several related works have already proposed to encode software architectures into PDDL. Existing planning algorithms can then be used in order to generate automatically a plan that updates an architecture to another one, i.e., the program of a recon guration. In this paper, we improve the encoding in PDDL. Noticeably we propose how to encode ADL types and constraints in the PDDL representation. That way, we can statically check our design and express PDDL constraints in order to ensure that the generated plan never goes through any bad or inconsistent architecture, not even temporarily.Comment: 6\`eme \'edition de la Conf\'erence Francophone sur les Architectures Logicielles (CAL 2012), Montpellier : France (2012

Issues of Architectural Description Languages for Handling Dynamic Reconfiguration

Dynamic reconfiguration is the action of modifying a software system at runtime. Several works have been using architectural specification as the basis for dynamic reconfiguration. Indeed ADLs (architecture description languages) let architects describe the elements that could be reconfigured as well as the set of constraints to which the system must conform during reconfiguration. In this work, we investigate the ADL literature in order to illustrate how reconfiguration is supported in four well-known ADLs: pi-ADL, ACME, C2SADL and Dynamic Wright. From this review, we conclude that none of these ADLs: (i) addresses the issue of consistently reconfiguring both instances and types; (ii) takes into account the behaviour of architectural elements during reconfiguration; and (iii) provides support for assessing reconfiguration, e.g., verifying the transition against properties.Comment: 6\`eme Conf\'erence francophone sur les architectures logicielles (CAL'2012), Montpellier : France (2012

Un modèle pour l'adaptation dynamique des programmes parallèles

Les environnements d'exécution tels que les grilles de calcul ou les fédérations de grappes ont leurs caractéristiques (telles que la bande passante) qui fluctuent au cours de l'exécution des programmes. C'est pourquoi il est nécessaire que les programmes soient capables de prendre en compte les changements de leur environnement d'exécution. L'adaptation dynamique est une technique qui a pour but de résoudre cette problématique. Cet article présente un modèle d'adaptation dynamique qui a été étendu au cas des codes parallèles

Enforcing consistency during the adaptation of a parallel component

International audienceAs Grid architectures provide execution environments that are distributed, parallel and dynamic, applications require to be not only parallel and distributed, but also able to adapt themselves to their execution environment. This article presents a model for designing self-adaptable parallel components that can be assembled to build applications for Grid. This model includes the definition of a consistency criterion for the dynamic adaptation of SPMD components. We propose a solution to implement this criterion. It has been evalued on both synthetic and real codes to exhibit the behavior of the several proposed strategies

Dynamic Adaptation of Parallel Codes: Toward Self-Adaptable Components for the Grid

International audienceOne of the challenges that come from the emergence of Grid architectures is to invent new programming techniques for these new platforms. As we explain in this chapter, we think that the architecture of the applications should reflect both the parallel and the distributed aspects of Grid architectures. It results in applications built as assemblies of parallel components. Since Grid architectures are known to be highly dynamic, using resources efficiently on such architectures is a challenging problem. Software must be able to react dynamically to the changes of the underlying execution environment. In order to help developers to create software for the Grid, we are investigating a model for the adaptation of parallel components. This chapter focuses on the adaptation mechanisms that are provided as a meta-level for components. We describe how a generic platform can help to develop efficient Grid software. First experimental results show the gain that can be expected from the use of such a platform

Polychronous Interpretation of Synoptic, a Domain Specific Modeling Language for Embedded Flight-Software

The SPaCIFY project, which aims at bringing advances in MDE to the satellite flight software industry, advocates a top-down approach built on a domain-specific modeling language named Synoptic. In line with previous approaches to real-time modeling such as Statecharts and Simulink, Synoptic features hierarchical decomposition of application and control modules in synchronous block diagrams and state machines. Its semantics is described in the polychronous model of computation, which is that of the synchronous language Signal.Comment: Workshop on Formal Methods for Aerospace (FMA 2009

Un modèle pour l'adaptation dynamique des programmes parallèles

Les environnements d'exécution tels que les grilles de calcul ou les fédérations de grappes ont leurs caractéristiques (telles que la bande passante) qui fluctuent au cours de l'exécution des programmes. C'est pourquoi il est nécessaire que les programmes soient capables de prendre en compte les changements de leur environnement d'exécution. L'adaptation dynamique est une technique qui a pour but de résoudre cette problématique. Cet article présente un modèle d'adaptation dynamique qui a été étendu au cas des codes parallèles

Performance and practicability of dynamic adaptation for parallel computing: An experience feedback from Dynaco

Since the concept of Grid computing has emerged, one of the major challenges consists in making applications able to benefit efficiently from the huge amount of resources without burdening the developer. Observing that Grid computin

A Negotioation-Based Approach of . . .

Novel architectures such as Grids have dynamic characteristics. Faults, nonexclusive access, and maintenance operations make resources come and go even during the execution time of applications. In order to deal with these events and continue the execution as good as possible, applications must be able to adapt to those changes of their execution environment. To do so, we propose a model in which an application chooses a special point in the future of its execution path at which it is able to modify itself. In the specific case of parallel applications, the threads must agree on the point to choose. This article presents a negotiation-based approach for reaching such an agreement. It focuses on the distributed algorithm executed by the threads to find such a point. This algorithm is compared to works that has been done in areas of distributed consensus and dialogue protocols of agents