A Dynamic Workflow Simulation Platform

International audienceAbstract--In numeric optimization algorithms errors at application level considerably affect the performance of their execution on distributed infrastructures. Hours of execution can be lost only due to bad parameter configurations. Though current grid workflow systems have facilitated the deployment of complex scientific applications on distributed environments, the error handling mechanisms remain mostly those provided by the middleware. In this paper, we propose a collaborative platform for the execution of scientific experiments in which we integrate a new approach for treating application errors, using the dynamicity and exception handling mechanisms of the YAWL workflow management system. Thus, application errors are correctly detected and appropriate handling procedures are triggered in order to save as much as possible of the work already executed

Resiliency in Distributed Workflows

In this report we present a thorough study of the concept of resiliency in distributed workflow systems. We focus particularly in applying this concept in fields like numerical optimization, where any software or logical error could mean restarting the entire experiment. A theoretical study is presented along with a set of software tools for implementation directions. At the end a resilient algorithm schema is proposed for later refinement and implementation.Dans ce rapport, nous présentons une étude approfondie de la notion de résilience dans les systèmes de workflow distribué. On a comme objectif particulier l'application de ce concept dans des domaines comme l'optimisation numérique, dont les erreurs des logiciels ou logiques pourraient signifier le redémarrage de l'expérience entière. Une étude théorique est présentée avec un ensemble d'outils logiciels pour la mise en oeuvre. En fin, un schéma d'un algorithme de résilience est proposé pour être raffiné et mise en oeuvre plus tard

A Distributed Workflow Platform for High-Performance Simulation

This report presents an approach to design, implement and deploy a simulation platform based on distributed workflows. It supports the smooth integration of existing software, e.g. Matlab, Scilab, Python, OpenFOAM, Paraview and user-defined programs. Additional features include the support for application-level fault-tolerance and exception-handling, i.e. resiliency, and the orchestrated execution of distributed codes on remote high-performance clusters.Ce rapport présente une approche pour la conception, la réalisation et le déploiement d'une plateforme de simulation basée sur les workflows. Elle permet l'intégration de logiciels existants comme MatLab, Scilab, Python, OpenFOAM et ParaView et de programmes utilisateurs. Elle permet également la tolérance aux pannes et le traitement d'exceptions, c-à-d la résilience, ainsi que l'exécution de codes distribués sur des clusters distants

A Distributed Workflow Platform for Simulation

Best Paper AwardInternational audienceThis paper presents an approach to design, implement and deploy a simulation platform based on distributed workflows. It supports the smooth integration of existing software, e.g. Matlab, Scilab, Python, OpenFOAM, Paraview and user-defined programs. The contribution of the paper is a new feature which supports application-level fault-tolerance and exception-handling, i.e., resilience.Cet article présente une approche pour concevoir, réaliser et déployer une plateforme de simulation basée sur les workflows distribués. Elle permet l'intégration de logiciels existant, par exemple Matlab, Scilab, Python, OpenFOAM, Paraview et de programmes définis par les utilisateurs. La contribution est ici le support de la tolérance aux pannes par les applications et le traitement des exceptions, c-à-d la résilience

A Resilience Approach to High-Performance Workflows

This report presents an approach to design, implement and deploy resilient distributed workflows. It supports the smooth integration of existing software for simulation applications, e.g. Matlab, Scilab, Python, OpenFOAM, Paraview and application programs. The contribution of the report is a new feature which supports resilience, i.e., application-level fault-tolerance and exception-handling. Connections with exascale computing requirements are also made. An overview of a prototype implementation based on the YAWL workflow management system is given.Ce rapport présente une approche pour concevoir, réaliser et déployer des workflows distribués et résilients. Elle permet l'intégration des logiciels de simulation numérique, par exemple Matlab, Scilab, Python, OpenFoam, ParaView et des codes d'applications. La contribution de ce rapport est une nouvelle fonctionnalité qui permet la résilience, c'est-à-dire la tolérance aux pannes des applications et le traitement d'exceptions. Le lien est également fait avec les besoins des futures applications exascale. On décrit un prototype basé sur le système de worflow YAWL

A Distributed Workflow Platform for High-Performance Simulation

This report presents an approach to design, implement and deploy a simulation platform based on distributed workflows. It supports the smooth integration of existing software, e.g. Matlab, Scilab, Python, OpenFOAM, Paraview and user-defined programs. Additional features include the support for application-level fault-tolerance and exception-handling, i.e. resiliency, and the orchestrated execution of distributed codes on remote high-performance clusters.Ce rapport présente une approche pour la conception, la réalisation et le déploiement d'une plateforme de simulation basée sur les workflows. Elle permet l'intégration de logiciels existants comme MatLab, Scilab, Python, OpenFOAM et ParaView et de programmes utilisateurs. Elle permet également la tolérance aux pannes et le traitement d'exceptions, c-à-d la résilience, ainsi que l'exécution de codes distribués sur des clusters distants

An enhanced bridged-based multi-hop wireless network implementation

Proceedings of: 5th Annual ICST Wireless Internet Conference (WICON 2010), 1-3 March 2010, SingaporeIn this paper an enhanced Layer-2 multi-hop wireless network implementation for Infrastructure based Wireless Mesh Networks is presented. This work combines the flexibility of Layer-2 Wireless Bridging with the dynamic self-configuring capabilities of MANET routing. The main contribution of this paper is an investigation of the issues encountered when applying a pure bridging based solution to wireless multi-hop networks and the development of several mechanisms to overcome these problems. This work was implemented and deployed in a real testbed environment using Routerboard hardware and utilising a number of open-source network tools in accordance with the needs of our platform. The developed testbed incorporates self-healing and self-configuration features without requiring a traditional MANET routing protocol. Instead the 802.11 beacon frames sent by the Access Points were extended with link information to allow optimal construction of the mesh topology. Results are presented which demonstrate the automated topology construction mechanism. Further results also show the enhancements made to the normal 802.11 Layer-2 mobility mechanism.European Community's Seventh Framework ProgramPublicad

A Dynamic Workflow Simulation Platform

International audienceAbstract--In numeric optimization algorithms errors at application level considerably affect the performance of their execution on distributed infrastructures. Hours of execution can be lost only due to bad parameter configurations. Though current grid workflow systems have facilitated the deployment of complex scientific applications on distributed environments, the error handling mechanisms remain mostly those provided by the middleware. In this paper, we propose a collaborative platform for the execution of scientific experiments in which we integrate a new approach for treating application errors, using the dynamicity and exception handling mechanisms of the YAWL workflow management system. Thus, application errors are correctly detected and appropriate handling procedures are triggered in order to save as much as possible of the work already executed

A Workflow Platform for Simulation on Grids

International audienceThis paper presents the design, implementation and deployment of a simulation platform based on distributed workflows. It supports the smooth integration of existing software, e.g., Matlab, Scilab, Python, OpenFOAM, ParaView and user-defined programs. Additional features include the support for application-level fault-tolerance and exception-handling, i.e., resilience, and the orchestrated execution of distributed codes on remote high-performance clusters

Resilient Workflows for Cooperative Design

International audienceThis paper describes an approach to extend process modeling for engineering design applications with fault-tolerance and resilience capabilities. It is based on the requirements for application-level error handling, which is a requirement for petascale and exascale scientific computing. This complements the traditional fault-tolerance management features provided by the existing hardware and distributed systems. These are often based on data and operations duplication and migration, and on checkpoint-restart procedures. We show how they can be optimized for high-performance infrastructures. This approach is applied on a prototype tested against industrial testcases for optimization of engineering design artifacts.his electronic document is a "live" template. The various components of your paper [title, text, heads, etc.] are already defined on the style sheet, as illustrated by the portions given in this document