Mediated Support for Learning Enhancement (ELLI) (Effective Lifelong Learning Inventory)

No abstract available

On the sustainability of large-scale computer science testbeds: the Grid'5000 case

In this position paper, we look at the financial sustainability of Grid'5000. The duration of the project (over 12 years) owesmore to successive investment decisions and continued support rather than from a wellunderstood and operated business model generating enough revenue tocovers costs and investments.In this paper, we will give an overview of a typical coststructure for a large-scale testbed, wesummarize with a few statements our views and develop pros and cons of a few funding sources. The way Grid'5000 is funded is detailed, before giving some data used to compute the unit cost for Grid'5000 resources

Using GASP for Collaborative Interaction within 3D Virtual Worlds

International audienceIn this paper, we present Gasp, a General Animation and Simulation Platform, whose purpose is to animate autonomous or userdriven agents, and we explain how it can be used for Collaborative Virtual Reality. First, we explain its architecture, based on the notion of simulation objects (or agents) associated with a calculation part (the behavior). Then we describe how it is possible to distribute eciently our agents upon a network in order to share the amount of calculation between several computers. Finally, as the visualisation of a simulation is also a simulation object, we show that our architecture allows us to distribute several visualisations upon a network to share a 3D interactive simulation between several users

On the sustainability of large-scale computer science testbeds: the Grid'5000 case

In this position paper, we look at the financial sustainability of Grid'5000. The duration of the project (over 12 years) owesmore to successive investment decisions and continued support rather than from a wellunderstood and operated business model generating enough revenue tocovers costs and investments.In this paper, we will give an overview of a typical coststructure for a large-scale testbed, wesummarize with a few statements our views and develop pros and cons of a few funding sources. The way Grid'5000 is funded is detailed, before giving some data used to compute the unit cost for Grid'5000 resources

Resources Description, Selection, Reservation and Verification on a Large-scale Testbed

International audienceThe management of resources on testbeds, including their description, reservation and verification, is a challenging issue, especially on of large scale testbeds such as those used for research on High Performance Computing or Clouds. In this paper, we present the solution designed for the Grid'5000 testbed in order to: (1) provide users with an in-depth and machine-parsable description of the testbed's resources; (2) enable multi-criteria selection and reservation of resources using a HPC resource manager; (3) ensure that the description of the resources remains accurate

Kerrighed: A SSI Cluster OS Running OpenMP

Writing parallel programs for clusters of workstations is still a challenging task. In this paper, we present Kerrighed, a Single System Image (SSI) operating system giving the illusion of an SMP machine, and providing the standard posix thread interface to developers. It is therefore possible to use Kerrighed to run OpenMP programs compiled for SMP-machines using the posix thread interface. In this paper, we explain how we managed to achieve that goal, and present the benefits of providing OpenMP support through the SSI approach as opposed to a dedicated run-time environment

Ghost Process: a Sound Basis to Implement Process Duplication, Migration and Checkpoint/Restart in Linux Clusters

Process management mechanisms (process duplication, migration and checkpoint/restart) are very useful for high performance and high availability in clustering systems. The single system image approach aims at providing a global process management service with mechanisms for process checkpoint, process migration and process duplication. In this context, a common mechanism for process virtualization is highly desirable but traditional operating systems do not provide such a mecahnism. This paper presents a kernel service for process virtualization called ghost process, extending the Linux kernel. The ghost process mechanism has been implemented in the Kerrighed single system image based on Linux. \\ Les mécanismes de gestion de processus (duplication, migration et création de point de reprise/reprise de processus) sont particulièrement intéressants pour les systèmes pour grappes de calculateurs à haute performance et à haute disponibilité. L'un des buts des systèmes à image unique est d'offrir un service de gestion globale des processus fondé sur des mécamismes de création de points de reprise de processus, de migration de processus et de duplication de processus. Dans ce contexte, un mécanisme commun pour la virtualisation de processus est hautement bénéfique mais les systèmes d'exploitation traditionnels n'offrent pas un tel mécanisme. Ce document présente un service noyau pour la virtualisation de processus, appelé processus fantôme, fondé sur une extension du noyau Linux. Le mécanisme de processus fantôme a été mis en oeuvre dans le système à image unique Kerrughed fondé sur Linux

Implementing SFA Support on an Established HPC-flavored Testbed: Lessons Learned

International audienceThe Slice-based Federation Architecture (SFA) is the de facto standard framework for managing testbeds, federations of testbeds, and users access to these federations. It is the foundation of most major testbed federations in the world, including GENI and Fed4FIRE. However, there remain some testbeds that were designed and grew outside of this world, making different, interesting and sometimes better design choices. In this paper, we describe how we added support for the GENI Aggregate Manager to the Grid'5000 testbed, a major testbed focused on HPC and Cloud that was developed for the most part independently for the last 15 years. From this experience, we draw some lessons and recommendations that could help improve the testbed management ecosystem

Gestion d'une infrastructure expérimentale de grande échelle avec Puppet et Git

National audienceGrid'5000 est une plate-forme expérimentale pour la recherche sur les systèmes distribués (P2P, grilles, Cloud, HPC, ...) composée de 1600 machines dans 26 clusters et 10 sites en France. La principale spécificité de la plate-forme est d'être reconfigurable par les utilisateurs, leur permettant ainsi de réaliser des expériences complexes : les utilisateurs peuvent ainsi déployer leur propre système d'exploitation avec Kadeploy, et s'isoler du reste de la plate-forme avec KaVLAN. L'équipe chargée d'administrer cette plate-forme est composée de 5 ingénieurs répartis sur les différents sites, avec peu d'expérience préalable de l'administration système et réseaux pour la plupart. Il a donc été nécessaire d'organiser le travail de l'équipe technique pour maximiser son efficacité. Au fil des ans, différentes solutions ont été étudiées, pour finalement retenir une solution composant les utilisations de Puppet, Git et Capistrano. Cette solution comporte actuellement 66 modules Puppet pour configurer 217 machines virtuelles. Cette présentation décrit les motivations qui ont conduit à choisir cette solution puis la solution elle-même, et l'infrastructure multi-sites mise en place pour diffuser les configurations en tentant de minimiser les problèmes que peut apporter un système centralisé. Un retour d'expérience critique et les améliorations futures envisagées seront également exposés

Mediated support for learning enhancement : ELLI, Effective Lifelong Learning Inventory

This is a paper from the ESCalate Academic Papers Online series, written by Margery McMahon, David Morrison-Love and Ruth Deakin-Crick in 2006. MacELLI is a learning enhancement project undertaken by the University of Glasgow and the University of Bristol. This paper explores an initiative offering students an opportunity for learning enhancement at a third level institution. The authors outline the nature of the initiative and discuss the preferred learning enhancement resource for the project, and consider the impact of the resource and its potential benefits for learners by reviewing the level of learner engagement with the project and student feedback on their experienc