Using MeDLey to resolve the Vlasov equation

Colloque avec actes et comité de lecture.Explicit parallelism relies on transmissions of messages between processes. However, as workstations are not intended to manage this kind of communications, it is necessary to use communication libraries, known as Message Passing. Currently, only MPI (Message Passing Interface) is still used, and its use became more complex. In order to solve this problem, a new language called MeDLey was developed, its purpose is to allow to the users an easier parallelism programming based on communications using Message Passing. In this paper, we will first overview the basics of the MeDLey syntax and semantics, before talking about the experimentation part of this language. This work is completed within team RESEDAS (Computer networks and Distributed systems) with the LORIA and INRIA Lorraine within the framework of a collaboration with the CCH (Lorraine Center of Competence in Modeling and Calculation with High Performance)

Using MeDLey for the Grid-Decomposition Methods

Colloque avec actes et comité de lecture. internationaleExplicit parallelism relies on transmissions of messages between processes. However, as workstations are not intended to manage this kind of communications, it is necessary to use communication libraries, known as Message Passing. Currently, only MPI (Message Passing Interface) is still used, and its use became more complexe. In order to solve this problem, a new language called MeDLey was developed, its purpose is to allow to the users an easier parallelism programming based on communications using Message Passing. In this paper, we will first overview the basics of the MeDLey syntax and semantics, before talking about the extension part of this language for the grid-decomposition methods

Experimentation and Extension of a Specification Language of the Communications for Distributed Computation

Explicit parallelism relies on transmissions of messages between processes. However, as workstations are not intended to manage this kind of communications, it is necessary to use communication libraries, known as Message Passing, which ensure data exchanges between parallel tasks of a same application. Currently, only MPI (Message Passing Interface) is still used, and its use became more complex. In order to solve this problem, a new language called MeDLey was developed ; its purpose is to allow the users an easier parallelism programming based on communications using Message Passing. MeDLey is an attempt to provide an abstract language to specify the communications of a distributed application independently from any current underlying communication layer. Based on this specification, a MeDLey compiler will generate several levels of implementation for all communication primitives : a first implementation based on PVM or MPI code, and a second one, more specific, more efficient, directly implemented on top of a network layer, or a more specific communication layer (active messages, shared memory, e.g.) to bypass the overhead introduced by message passing libraries. As for any data-processing tool, the experimentation of the MeDLey language was of obvious need, therefore the topic of this work whose aim initially is to experiment this language on real example, then to propose some extensions which prove to be necessary in the applications based on communications by Message Passing. This work is completed within team RESEDAS (Computer networks and Distributed systems) with the CRIN-CNRS & INRIA Lorraine within the framework of a collaboration with the Center Charles Hermite (Lorraine Center of Competence in Modeling and Calculation with High Performance). In this paper, we will first overview the basics of the MeDLey syntax and semantics, before talking about the experimentation and extension parts of this language

Méthodes et outils pour les communications dans les applications de calcul distribué

MeDLey (Message Definition Language) is a specification language of communications for distributed computation. Its aim is to provide to the user an abstract vision of his/her application in terms of tasks and exchanges between these tasks independently of material architecture and the means ofcommunication used. Based oh this specification, the MeDLey compiler generates several levels of implementations for various communication primitives.The original contribution of our thesis was guided by the need to evolve this language. We focused our search on the parallel architectures with distributed memory; especially those composed from a network of workstations.Within this framework, a first extension related to the collective communications; we proposed a new approacb allowing to specify and carry out this type of communication. The second extension related tothe grid.-decomposition methods; we defined a new interconnection model, then proposed functionsallowing the use of these methods. The third extension aimed to implement the MeDLey language in aCORBA environment. This choice is justified by the adantage of CORBA in term of interoperability and isolation between client and server, using network protocol, material infrastructure, programming languageand data transport mechanisms. In order to implement the MeDLey language in CORBA, we developed amessage-passing library called MPC (Message Passing in CORBA). This library is based on the use of the methods invocation mechanism on remote objects of CORBA and proposes a complete and usuai message passing environment in CORBA. Finally, our last work concemed the experimentation and the validation of the developed tools. In this context, an expcrimentation of the MeDLey language consisted on the implementation of al simulation code used by the physicists. Then, we validated the point-ta-point communication protocol of the MPClibrary by using TLA (Temporal Logic of Actions) .MeDLey (Message Defintion Language) est un langage de spécification des communications pour les applications parallèles. Son principe repose sur l'implantation des communications sur différentes plateformesde communication en utilisant un langage et une syntaxe unifiés.L'apport original de la thèse a été guidé par le besoin de faire évoluer ce langage pour couvrir un champ d'application plus vaste. Nous avons focalisé nos recherches sur les architectures parallèles à mémoire distribuée composées d'un réseau de stations. Dans ce cadre, une première extension a concerné les communications collectives ; nous avons proposé une nouvelle approche permettant de spécifier et réaliser ce type de communication. La deuxième extension a concerné les méthodes de décomposition de domaine; nous avons définit un nouveau moded'interconnexion, puis proposé des fonctions permettant d'appliquer ces méthodes. La troisième extension avait pour objectif l'implantation de ce langage dans un environnement CORBA. Ce choix est justifié d'unepart par les performances de CORBA au niveau du temps de communication au vu des tests que nous avons réalisés; et d'autre part par les avantages de cet environnement en terme de services, en particulier celuid'interopérabilité. Pour y parvenir, nous avons développé une bibliothèque de communication par échange de messages au dessus du CORBA appelée MPC (Message Passing in Corba environment) qui propose un environnement complet pour la programmation par échange de messages dans un environnement CORBA.Enfin, nos derniers travaux ont portés sur l'expérimentation et la validation des outils développés. Dans ce contexte, une expérimentation du langage MeDLey a consisté à l'implantation d'un code de simulation numérique utilisé par les physiciens. Ensuite, nous avons validé le protocole de communicationpoint à point de la bibliothèque MPC en utilisant TLA (Temporal Logie of Actions)

METHODES ET OUTILS POUR LES COMMUNICATIONS DANS LES APPLICATIONS DE CALCUL DISTRIBUE

MEDLEY (MESSAGE DEFINITION LANGUAGE) EST UN LANGAGE DE SPECIFICATION DES COMMUNICATIONS POUR LES APPLICATIONS PARALLELES. SON PRINCIPE REPOSE SUR L'IMPLANTATION DES COMMUNICATIONS SUR DIFFERENTES PLATES-FORMES DE COMMUNICATION EN UTILISANT UN LANGAGE ET UNE SYNTAXE UNIFIES. L'APPORT ORIGINAL DE LA THESE A ETE GUIDE PAR LE BESOIN DE FAIRE EVOLUER CE LANGAGE POUR COUVRIR UN CHAMP D'APPLICATION PLUS VASTE. NOUS AVONS FOCALISE NOS RECHERCHES SUR LES ARCHITECTURES PARALLELES A MEMOIRE DISTRIBUEE COMPOSEES D'UN RESEAU DE STATIONS. DANS CE CADRE, UNE PREMIERE EXTENSION A CONCERNE LES COMMUNICATIONS COLLECTIVES ; NOUS AVONS PROPOSE UNE NOUVELLE APPROCHE PERMETTANT DE SPECIFIER ET REALISER CE TYPE DE COMMUNICATION. LA DEUXIEME EXTENSION A CONCERNE LES METHODES DE DECOMPOSITION DE DOMAINE ; NOUS AVONS DEFINIT UN NOUVEAU MODE D'INTERCONNEXION, PUIS PROPOSE DES FONCTIONS PERMETTANT D'APPLIQUER CES METHODES. LA TROISIEME EXTENSION AVAIT POUR OBJECTIF L'IMPLANTATION DE CE LANGAGE DANS UN ENVIRONNEMENT CORBA. CE CHOIX EST JUSTIFIE D'UNE PART PAR LES PERFORMANCES DE CORBA AU NIVEAU DU TEMPS DE COMMUNICATION AU VU DES TESTS QUE NOUS AVONS REALISES ; ET D'AUTRE PART PAR LES AVANTAGES DE CET ENVIRONNEMENT EN TERME DE SERVICES, EN PARTICULIER CELUI D'INTEROPERABILITE. POUR Y PARVENIR, NOUS AVONS DEVELOPPE UNE BIBLIOTHEQUE DE COMMUNICATION PAR ECHANGE DE MESSAGES AU DESSUS DU CORBA APPELEE MPC (MESSAGE PASSING IN CORBA ENVIRONMENT) QUI PROPOSE UN ENVIRONNEMENT COMPLET POUR LA PROGRAMMATION PAR ECHANGE DE MESSAGES DANS UN ENVIRONNEMENT CORBA. ENFIN, NOS DERNIERS TRAVAUX ONT PORTES SUR L'EXPERIMENTATION ET LA VALIDATION DES OUTILS DEVELOPPES. DANS CE CONTEXTE, UNE EXPERIMENTATION DU LANGAGE MEDLEY A CONSISTE A L'IMPLANTATION D'UN CODE DE SIMULATION NUMERIQUE UTILISE PAR LES PHYSICIENS. ENSUITE, NOUS AVONS VALIDE LE PROTOCOLE DE COMMUNICATION POINT A POINT DE LA BIBLIOTHEQUE MPC EN UTILISANT TLA (TEMPORAL LOGIC OF ACTIONS).NANCY1-SCD Sciences & Techniques (545782101) / SudocVILLEURBANNE-DOC'INSA LYON (692662301) / SudocSudocFranceF

A broadcast message passing protocol based on corba event service

Colloque avec actes et comité de lecture. internationale.International audienceThe need for interoperability among the rapidly proliferating number of hardwares and softwares led to the definition of CORBA (Common Object Request Broker Architecture). This architecture offers a good interoperability and communication support and the use of such architecture for distributed metacomputing applications seems interesting and promising. However, its implementation is difficult because of protocol diversity and communication modes used by parallel applications. To cure this problem, we develop a message passing library in CORBA environment called MPC (Message Passing in CORBA). In this paper, we quickly present the basic concepts of this library and its broadcast protocol based on the CORBA event service

MPC: a new Message Passing library in Corba

Colloque avec actes et comité de lecture. internationale.International audienceThe need for interoperability among the rapidly proliferating number of hardwares and softwares led to the definition of CORBA (Common Object Request Broker Architecture), which standardizes the execution support of distributed object applications. This architecture offers a good interoperability and encapsulation support. In addition, the method invocation mechanism, offers several features and can be used as a good communication model. Consequently, the use of such architecture for distributed metacomputing applications seems interesting and promising. However, its implementation is difficult because of protocol diversity and communication modes used by parallel applications. Moreover, this diversity of protocols is added to the intrinsic difficulty of the use of object design approach and basic mechanisms of CORBA components. To cure this problem, we develop a message passing library in CORBA environment called MPC (Message Passing in CORBA). In this paper, we quickly present the basic concepts of this library and the point-to-point communication protocol used

Using Medley in a CORBA environment

Colloque avec actes et comité de lecture.Modern technologies including rapid increase in speed and availability of network of supercomputer provides the infrastructure necessary to develop distributed applications and making high performance global computing possible. The performance potential offered is enormous but generally is hard and tedious to obtain due to the complexity of developing applications in such distributed environment. In this paper, we introduce \medley which is a specification language of communications for parallel applications. Its aim is to provide to the user an abstract vision of his application in terms of tasks and exchanges between these tasks independently of material architecture and the means of communication used. Based on this specification, the \medley compiler generates several levels of implementation for various communication primitives. More precisely, we will detail in this article, a new approach of this language allowing the implementation of the communications based on ideas underlying the Common Object Request Broker Architecture \emph{CORBA}

Spécification des communications pour le calcul M-SPMD dans un environnement CORBA

Colloque avec actes et comité de lecture. nationale.National audienceMedley est un langage de spécification des communications pour les applications parallèles. Son but est de fournir à l'utilisateur une vision abstraite de son application en termes de tâches et d'échanges entre ces tâches indépendamment de l'architecture matérielle et des moyens de communication utilisés. À partir d'une spécification, le compilateur de ce langage génère plusieurs niveaux d'implantation pour différentes primitives de communication. Dans cet article, nous allons détailler une nouvelle approche de ce langage permettant l'implantation des communications dans un environnement CORBA

MeDLey: from Point-to-Point to Collective Communications

Colloque avec actes et comité de lecture. internationale.International audienceModern technologies including rapid increase in speed and availability of network of supercomputer provides the infrastructure necessary to develop distributed applications and making high performance global computing possible. The performance potential offered is enormous but generally is hard and tedious to obtain due to the complexity of developing applications in such distributed environment. To cure this problem, we introduce MeDLey which is a specification language of communications for parallel applications. In this paper, we will first overview the basics of the MeDLey syntax and semantics, before talking about the extension part of this language for the collective communications