HP-CERTI: Towards a high performance, high availability open source RTI for composable simulations (04F-SIW-014)

Composing simulations of complex systems from already existing simulation components remains a challenging issue. Motivations for composable simulation include generation of a given federation driven by operational requirements provided "on the fly". The High Level Architecture, initially developed for designing fully distributed simulations, can be considered as an interoperability standard for composing simulations from existing components. Requirements for constructing such complex simulations are quite different from those discussed for distributed simulations. Although interoperability and reusability remain essential, both high performance and availability have also to be considered to fulfill the requirements of the end user. ONERA is currently designing a High Performance / High Availability HLA Run-time Infrastructure from its open source implementation of HLA 1.3 specifications. HP-CERTI is a software package including two main components: the first one, SHM-CERTI, provides an optimized version of CERTI based on a shared memory communication scheme; the second one, Kerrighed-CERTI, allows the deployment of CERTI through the control of the Kerrighed Single System Image operating system for clusters, currently designed by IRISA. This paper describes the design of both high performance and availability Runtime Infrastructures, focusing on the architecture of SHM-CERTI. This work is carried out in the context of the COCA (High Performance Distributed Simulation and Models Reuse) Project, sponsored by the DGA/STTC (Délégation Générale pour l'Armement/Service des Stratégies Techniques et des Technologies Communes) of the French Ministry of Defense

Diseño de un clúster con computadoras dadas de baja, como alternativa de bajo costo frente a ordenadores de alto rendimiento, para empresas del Eje Cafetero

El aporte a las empresas de la región se puede realizar en diferentes formas, pero cuando se pueden reunir diferentes aspectos como la reutilización de elementos que han sido descartados, el alivio en los gastos de la organización, el apoyo al medio ambiente mediante la disminución de desechos de equipos tecnológicos y la posibilidad de contar con un sistema fruto de la unión de hardware y software que pueda generar unas capacidades aceptables, la propuesta es más atractiva, no solo desde el punto de vista empresarial, sino también desde el ambiental y social. En el presente documento se presenta una propuesta basada en el diseño de un clúster con equipos no activos en la empresa y se estudia su viabilidad, de tal forma que se tenga un sistema que pueda brindar beneficios como: ¿ Ayudar a reducir la contaminación generada por los desechos tecnológicos. ¿ Hacer uso eficiente de los recursos tecnológicos que puede poseer una empresa. ¿ Contar con un sistema de buenas prestaciones para la ejecución de aplicaciones que necesitan ordenadores de medio o alto rendimiento. En la metodología para el desarrollo del proyecto se encuentran el estudio teórico en lo relacionado a sistemas de clúster, conocer a partir de un grupo de empresas el escenario en el cual se puede desarrollar un proyecto como el propuesto, el diseño de un sistema clúster y los resultados obtenidos de la investigación que permita conocer la viabilidad de un proyecto de esta naturaleza

Single system image: A survey

Single system image is a computing paradigm where a number of distributed computing resources are aggregated and presented via an interface that maintains the illusion of interaction with a single system. This approach encompasses decades of research using a broad variety of techniques at varying levels of abstraction, from custom hardware and distributed hypervisors to specialized operating system kernels and user-level tools. Existing classification schemes for SSI technologies are reviewed, and an updated classification scheme is proposed. A survey of implementation techniques is provided along with relevant examples. Notable deployments are examined and insights gained from hands-on experience are summarized. Issues affecting the adoption of kernel-level SSI are identified and discussed in the context of technology adoption literature

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

Evolving an efficient and effective off-the-shelf computing infrastructure for schools in rural areas of South Africa

Upliftment of rural areas and poverty alleviation are priorities for development in South Africa. Information and knowledge are key strategic resources for social and economic development and ICTs act as tools to support them, enabling innovative and more cost effective approaches. In order for ICT interventions to be possible, infrastructure has to be deployed. For the deployment to be effective and sustainable, the local community needs to be involved in shaping and supporting it. This study describes the technical work done in the Siyakhula Living Lab (SLL), a long-term ICT4D experiment in the Mbashe Municipality, with a focus on the deployment of ICT infrastructure in schools, for teaching and learning but also for use by the communities surrounding the schools. As a result of this work, computing infrastructure was deployed, in various phases, in 17 schools in the area and a “broadband island” connecting them was created. The dissertation reports on the initial deployment phases, discussing theoretical underpinnings and policies for using technology in education as well various computing and networking technologies and associated policies available and appropriate for use in rural South African schools. This information forms the backdrop of a survey conducted with teachers from six schools in the SLL, together with experimental work towards the provision of an evolved, efficient and effective off-the-shelf computing infrastructure in selected schools, in order to attempt to address the shortcomings of the computing infrastructure deployed initially in the SLL. The result of the study is the proposal of an evolved computing infrastructure model for use in rural South African schools

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