HOCL Programming Guide

HOCL(Higher Order Chemical Language) is a chemical programming language. Computations can be seen as chemical reactions which are controlled by a set of chemical rules. An HOCL program is composed of two parts: chemical rule definitions and solution organization. This article aims at introducing how to write chemical programs using HOCL

MYOAN : an implementation of the KOAN shared virtual memory on the Intel paragon

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HOCL Installation Guide

HOCL (Higher Order Chemical Language) is a chemical programming language. Computations can be seen as chemical reactions which are controlled by a set of chemical rules. We have an HOCL compiler developed in JAVA. This manual aims at presenting how to install and then use this compiler to compile and execute the HOCL programs

Directions in parallel programming: HPF, shared virtual memory and object parallelism in pC++

Fortran and C++ are the dominant programming languages used in scientific computation. Consequently, extensions to these languages are the most popular for programming massively parallel computers. We discuss two such approaches to parallel Fortran and one approach to C++. The High Performance Fortran Forum has designed HPF with the intent of supporting data parallelism on Fortran 90 applications. HPF works by asking the user to help the compiler distribute and align the data structures with the distributed memory modules in the system. Fortran-S takes a different approach in which the data distribution is managed by the operating system and the user provides annotations to indicate parallel control regions. In the case of C++, we look at pC++ which is based on a concurrent aggregate parallel model

A Chemistry-Inspired Workflow Management System for a Decentralized Composite Service Execution

With the recent widespread adoption of service-oriented architecture, the dynamic composition of such services is now a crucial issue in the area of distributed computing. The coordination and execution of composite Web services are today typically conducted by heavyweight centralized workflow engines, leading to an increasing probability of processing and communication bottleneck and failures. In addition, centralization induces higher deployment costs, such as the computing infrastructure to support the workflow engine, which is not affordable for a large number of small businesses and end-users. Last but not least, central workflow engines leads to diverse inadequate consequences dealing with privacy or energy consumption. In a world where platforms are more and more dynamic and elastic as promised by cloud computing, decentralized and dynamic interaction schemes are required. Addressing the characteristics of such platforms, nature-inspired analogies recently regained attention to provide autonomous service coordination on top of dynamic large scale platforms. In this report, we propose a decentralized approach for the execution of composite Web services based on an unconventional programming paradigm that relies on the chemical metaphor. It provides a high-level execution model that allows executing composite services in a fully decentralized manner. Composed of services communicating through a persistent shared space containing control and data flows between services, our architecture allows to distribute the composition among nodes without the need for any centralized coordination. A proof of concept is given, through the deployment of a software prototype implementing these concepts, showing the viability of an autonomic vision of service composition.Suite à l'adoption grandissante des architectures orientées service, la composition dynamique de services est devenu un problème important de la construction de plates-formes de calcul distribué. La coordination et l'exécutiuon de Web Service composites sont aujourd'hui typiquement conduits par des moteurs de "workflows" (graphes de composition de services, formant un "service composite") centralisés, entrainant différents problèmes, et notamment une probabilité grandissante d'apparition d'échecs ou de goulots d'étranglement. Dans un monde où les plate-formes sont de plus en plus dynamiques (ou "élastiques", comme envisagé par les "clouds", de nouveaux mécanismes de coordination dynamiques sont requis. Dans ce contexte, des métaphores naturelles ont gagné une attention particulière récemment, car elles fournissent des abstractions pour la coordination autonome d'entités (commes les services.) Dans ce rapport, une approche décentralisée pour l'exécution de Web Services composites fondée sur la métaphore chimique, qui fournit un modèle d'exécution haut-niveau pour l'exécution décentralisée, est présentée. Dans cette architecture, les services communiquent à travers un espace virtuellement partagé persistant contenant l'information sur les flux de contrôle et de données, permettant une coordination décentralisée des services. Un prototype logiciel a été développé et expérimenté. Les résultats de ces expériences sont présentés à la fin de ce rapport

A Chemistry-Inspired Workflow Management System for Scientific Applications in Clouds

International audienceWith the proliferation of Web Services, scientific applications are more and more designed as temporal composition of services, commonly referred to as, workflows. To address this paradigm shift, different workflow management systems have been proposed. If their efficiency has been established over centralized reliable systems, it is questionable over highly decentralized failure-prone platforms. Scientific applications started to be deployed over emerging clouds, leading to new issues, like elasticity, i.e., the possibility to dynamically refine at runtime the amount of resources dedicated to an application. This raised a new demand for programming models, able to express autonomic self-coordination of services in a dynamic, elastic platform. Chemistry-inspired computing recently regained momentum in this context, naturally expressing parallelism, distribution, and autonomic behaviors. While its high expressiveness and adequacy for this context has been established, the chemical model severely suffers from a lack of proof of concepts. In this paper, we concretely show how to leverage such models in this context. We focus on the design, the implementation and the experimental validation of a chemistry-inspired scientific workflow management system

Partage de mémoire à très grande échelle sur des réseaux pair-à-pair

Cet article explore une direction nouvelle dans le domaine de la gestion de données à très grande échelle: le partage de mémoire à l'aide de techniques pair-à-pair (Peer-to-Peer). Les développements actuels dans ce domaine se sont focalisés sur le partage de fichiers. Nous montrons l'intérêt de partager les espaces mémoire des noeuds, et non plus seulement leurs fichiers. Cette idée conduit à repenser complètement la problématique de la mémoire virtuellement partagée dans le contexte du calcul global sur l'Internet ou des grilles de calcul, permettant de rendre la gestion des données aussi transparente que celle des calculs. Nous proposons l'environnement JXTA comme plate-forme de développement de cette approche

Lancer de rayon : approches parallèles

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Deploying CORBA Components on a Computational Grid: General Principles and Early Experiments Using the Globus Toolkit

The deployment of high bandwidth wide-area networks has led computational grids to offer a very powerful computing resource. In particular, this inherently distributed resource is well-suited for multiphysics applications. To face the complexity of such applications, the software component technology appears to be a very adequate programming model. However, to take advantage of the computational power of grids, component-based applications should be automatically deployed in computational grids. Based on the CORBA component specifications for the deployment of components, which seem to currently be the most complete, this paper proposes a detailed process for component deployment in computational grids. It also reports on early experiments on deploying CORBA components in a computational grid using the Globus Toolkit 2.4

Rule-driven service coordination middleware for scientific applications

International audienceWith the proliferation of Web services, scientific applications are more and more designed as temporal compositions of services, commonly referred to as workflows. To address this paradigm shift, different workflow management systems have been proposed. While their efficiency has been established over centralized static systems, it is questionable over decentralized failure-prone platforms. Scientific applications recently started to be deployed over large distributed computing platforms, leading to new issues, like elasticity, i.e., the possibility to dynamically refine, at runtime, the amount of resources dedicated to an application. This raised again the demand for new programming models, able to express autonomic self-coordination of services in a dynamic platform. Nature-inspired, rule-based computing models recently gained a lot of attention in this context. They are able to naturally expressing parallelism, distribution, and autonomic adaptation. While their high expressiveness and adequacy for this context has been established, such models severely suffer from a lack of proof of concepts. In this paper, we concretely show how to leverage such models in this context. We focus on the design, the implementation and the experimental validation of a chemistry-inspired scientific workflow management system