Containers : A Sound Basis For a True Single System Image

Clusters of SMPs are attractive for executing shared memory parallel applications but reconciling high performance and ease of programming remains an open issue. A possible approach is to provide an efficient Single System Image (SSI) operating system giving the illusion of an SMP machine. In this paper, we introduce the concept of container as a mechanism to unify global resource management at the lowest operating system level. Higher level operating system services such as virtual memory system and file cache can be easily implemented based on containers and transparently take benefit of the whole memory resource available in the cluster

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

Snooze: A Scalable, Fault-Tolerant and Distributed Consolidation Manager for Large-Scale Clusters

International audienceIntelligent workload consolidation and dynamic cluster adaptation offer a great opportunity for energy savings in current large-scale clusters. Because of the heterogeneous nature of these environments, scalable, fault-tolerant and distributed consolidation managers are necessary in order to efficiently manage their workload and thus conserve energy and reduce the operating costs. However, most of the consolidation managers available nowadays do not fulfill these requirements. Hence, they are mostly centralized and solely designed to be operated in virtualized environments. In this work, we present the architecture of a novel scalable, fault-tolerant and distributed consolidation manager called Snooze that is able to dynamically consolidate the workload of a software and hardware heterogeneous large-scale cluster composed out of resources using the virtualization and Single System Image (SSI) technologies. Therefore, a common cluster monitoring and management API is introduced, which provides a uniform and transparent access to the features of the underlying platforms. Our architecture is open to support any future technologies and can be easily extended with monitoring metrics and algorithms. Finally, a comprehensive use case study demonstrates the feasibility of our approach to manage the energy consumption of a large-scale cluster

OpenMosix, OpenSSI and Kerrighed: A Comparative Study

This paper presents a comparative study of Kerrighed, openMosix and OpenSSI, three Single System Image (SSI) operating systems for clusters. This experimental study gives an overview of SSI features offered by these SSI and evaluates performance of such features

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

Reducing Kernel Development Complexity In Distributed Environments

Setting up generic and fully transparent distributed services for clusters implies complex and tedious kernel developments. More flexible approaches such as user-space libraries are usually preferred with the drawback of requiring application recompilation. A second approach consists in using specific kernel modules (such as FUSE in Gnu/Linux system) to transfer kernel complexity into user space. In this paper, we present a new way to design and implement kernel distributed services for clusters by using a cluster wide consistent data management service. This system, entitled kDDM for "kernel Distributed Data Management", offers flexible kernel mechanisms to transparently manage remote accesses, cache and coherency. We show how kDDM simplifies distributed kernel developments by presenting the design and the implementation of a service as complex as a fully symmetric distributed file system. The innovative approach of kDDM has the potential to boost the development of distributed kernel services because it relieves the developers of the burden of dealing with distributed protocols and explicit data transfers. Instead, it allows focusing on the implementation of services in a manner very similar to that of parallel programming on SMP systems. More generally, the use of kDDM could be exploited in almost all local kernel services to extend them to cluster scale. Cluster wide IPC, distributed namespaces (such as /proc) or process migration are some potential examples

Snooze: A Scalable, Fault-Tolerant and Distributed Consolidation Manager for Large-Scale Clusters

Intelligent workload consolidation and dynamic cluster adaptation offer a great opportunity for energy savings in current large-scale clusters. Because of the heterogeneous nature of these environments, scalable, fault-tolerant and distributed consolidation managers are necessary in order to efficiently manage their workload and thus conserve energy and reduce the operating costs. However, most of the consolidation managers available nowadays do not fulfill these requirements. Hence, they are mostly centralized and solely designed to be operated in virtualized environments. In this work, we present the architecture of a novel scalable, fault-tolerant and distributed consolidation manager called Snooze that is able to dynamically consolidate the workload of a software and hardware heterogeneous large-scale cluster composed out of resources using the virtualization and Single System Image (SSI) technologies. Therefore, a common cluster monitoring and management API is introduced, which provides a uniform and transparent access to the features of the underlying platforms. Our architecture is open to support any future technologies and can be easily extended with monitoring metrics and algorithms. Finally, a comprehensive use case study demonstrates the feasibility of our approach to manage the energy consumption of a large-scale cluster.Une consolidation intelligente des charges applicatives et une adaptation dynamique des grappes de calculateurs offrent des opportunités importantes d'économiser l'énergie dans les grappes de calculateurs actuelles. Étant donnée la nature hétérogène de ces environnements, il est nécessaire de fournir des gestionnaires de consolidation passant à l'échelle, tolérants aux fautes, et distribués, afin de gérer efficacement les charges applicatives de ces grappes et ainsi économiser l'énergie et réduire les coûts opérationnels. Cependant, la plupart des gestionnaires de consolidation disponibles de nos jours ne satisfont pas ces critères. Ainsi, ces gestionnaires de consolidation sont pour la plupart centralisés et ne sont conçus que pour des environnements virtualisés. Dans ce travail, nous présentons l'architecture d'un nouveau gestionnaire de consolidation passant à l'échelle, tolérant aux fautes, et distribué, appelé Snooze, qui est capable de consolider dynamiquement la charge applicative d'une grappe hétérogène du point de vue logiciel comme du point de vue matériel, de grande taille, et composée de ressources utilisant les technologies de virtualisation et de système à image unique (SSI). Pour cela une API commune pour la supervision et la gestion d'une grappe est présentée. Cette API permet d'accéder de façon uniforme et transparente aux fonctionnalités des plates-formes sous-jacentes. Notre architecture est ouverte afin d'être adaptable aux technologies futures, et peut être étendue aisément avec d'autres métriques et algorithmes de supervision. Enfin, une étude complète de cas d'utilisation montre la faisabilité de notre approche pour gérer la consommation d'énergie d'une grappe de grande taille

Hermeneutic of Disjunctive Worlds : Fantasy and Science Fiction (1950-1989)

L’objectif de notre travail est de réunir, au sein d’une analyse commune, les récits de science-fiction et de fantasy, d’en comprendre les mécanismes transversaux et d’en proposer à la fois une relecture et une herméneutique. Pour cela, nous posons l’hypothèse, en nous appuyant sur les travaux de Mircea Eliade et Marc Angenot, que les récits de fantasy et de science-fiction sont des « histoires sacrées » soutenues par un deus otiosus au sein de mondes disjonctifs. La diégèse (le monde fictionnel) de ces récits inclut donc un sacré qui se manifeste (hiérophanies) différemment selon les récits, suivant la sensibilité (Roger Caillois) des personnages, malgré l’apparition de motifs récurrents (l’origine, la paternité, l’espace, la prédiction) et de figures fréquentes (l’apocalypse, la cosmogonie, le père, la mère, le paysage, la prophétie…) ce qui implique une organisation sociale du sacré (Hannah Arendt). A partir de là, nous observons les régulations (Gilles Deleuze, Félix Guattari ; Roger Caillois) du sacré dans la diégèse et les constantes et variables qui se dégagent au niveau du temps (Mircea Eliade ; Jean-Marie Grassin ; Jean-Paul Engélibert ; Niccholas Serruys), de l’espace (Anna Bugajska ; Roger Caillois ; Hannah Arendt) et de la justice (Roger Caillois ; Hélène Machinal ; Brian Attebery). L’espace diégétique apparait comme un composé de sacré et de profane qui nous permet l’observation de mécanismes transversaux à tous les récits. Notre dernière partie applique les constantes et les variables, issues de notre deuxième partie, articulées par le personnage et sa quête, à des ouvrages opposés par la critique afin de relire l’opposition de la science-fiction et de la fantasy et d’en proposer une relecture commune, dépassant les frontières génériques et temporelles. Les mondes disjonctifs alors des « histoires sacrées » dont les constantes et les variables, dans leur articulation, deviennent une métaphore sociale du sacré.The aim of our work is to understand, in a same analysis, the stories of science fiction and fantasy, to extract the transversal mechanisms and to propose, in a same time, a rereading and a hermeneutic. 333 We base our analysis on the hypothesis that the stories of science fiction and fantasy are “sacred stories” (Mircea Eliade) maintained, in the diegesis (fictional world), by a deus otiosus which is called by Marc Angenot, the absent paradigm. By mixing the works of Marc Angenot and Mircea Eliade, we propose the assumption that the diegesis contains a sacred that emerges (hierophanies) by many ways, and depends on the sensibility of the characters (Roger Caillois). However, we can observe recurrent frames (the origin, the paternity, the space, the prediction) and repetitive figures (the apocalypse, the cosmogony, the father, the mother, the landscape, the prophecy, etc.) that imply a social organization of the sacred (Hannah Arendt). In our second part, we observe the fluctuations (Gilles Deleuze, Félix Guattari ; Roger Caillois) of the sacred in the diegesis and we extract the constants and the variables about the time (Mircea Eliade ; Jean-Marie Grassin ; Jean-Paul Engélibert ; Niccholas Serruys), the space (Anna Bugajska ; Roger Caillois ; Hannah Arendt) and the justice (Roger Caillois ; Hélène Machinal ; Brian Attebery). So, the diegetic space is made up by sacred and profane which allows us to observe transversal mechanisms in the stories. Our last part, we apply the constants and the variables extracted from the second part and centred around the main character and his quest. We chose productions opposed by the critics to reread the division between the science fiction and the fantasy and to propose a new and common perspective, beyond the generic and temporal borders. So the disjunctive worlds appear like “sacred stories” with variables and constants that are a social metaphor of the sacred

Caracterisation des couches minces d'oxyde de titane pour filtres optiques

SIGLECNRS T Bordereau / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc