International audienceLarge scale distributed systems such as Grids are difficult to study from theoretical models and simulators only. Most Grids deployed at large scale are production platforms that are inappropriate research tools because of their limited reconfiguration, control and monitoring capabilities. In this paper, we present Grid'5000, a 5000 CPU nation-wide infrastructure for research in Grid computing. Grid'5000 is designed to provide a scientific tool for computer scientists similar to the large-scale instruments used by physicists, astronomers, and biologists. We describe the motivations, design considerations, architecture, control, and monitoring infrastructure of this experimental platform. We present configuration examples and performance results for the reconfiguration subsystem

Abstract

Among existing grid middleware approaches, one simple, powerful, and flexible approach consists of using servers available in different administrative domains through the classical client-server or Remote Procedure Call (RPC) paradigm. Network Enabled Servers implement this model also called GridRPC. Clients submit computation requests to a scheduler whose goal is to find a server available on the grid. The aim of this paper is to give an overview of a middleware developed in the GRAAL team called DIET 1 . DIET (Distributed Interactive Engineering Toolbox) is a hierarchical set of components used for the development of applications based on computational servers on the grid. RésuméParmi les intergiciels de grilles existants, une approche simple, flexible et performante consisteà utiliser des serveurs disponibles dans des domaines administratifs différentsà travers le paradigme classique de l'appel de procédureà distance (RPC). Les environnements de ce type, connus sous le terme de Network Enabled Servers, implémentent ce modèle appelé GridRPC. Des clients soumettent des requêtes de calculà un ordonnanceur dont le but consisteà trouver un serveur disponible sur la grille. Le but de cet article est de donner un tour d'horizon d'un intergiciel développé dans le projet GRAAL appelé DIET 2 . DIET (Distributed Interactive Engineering Toolbox) est un ensemble hiérarchique de composants utilisés pour le développement d'applications basées sur des serveurs de calcul sur la grille.

International audienceThe Cloud phenomenon brings along the cost-saving benefit of dynamic scaling. As a result, the question of efficient resource scaling arises. Prediction is necessary as the virtual resources that Cloud computing uses have a setup time that is not negligible. We propose an approach to the problem of workload prediction based on identifying similar past occurrences of the current short-term workload history. We present in detail the Cloud client resource auto-scaling algorithm that uses the above approach to help when scaling decisions are made, as well as experimental results by using real-world traces from Cloud and Grid platforms. We also present an overall evaluation of this approach, its potential and usefulness for enabling efficient auto-scaling of Cloud user resources

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This report presents the architecture and the algorithms used in DIET (Distributed Interactive Engineering Toolbox), a hierarchical set of components to build Network Enabled Server applications in a Grid environment. This environment is built on top of different tools which are able to locate an appropriate server depending of the client's request, the data location (which can be anywhere on the system, because of previous computations) and the dynamic performance characteristics of the system. Some experiments are related at the end of this report, that exhibit the low cost of adding branches in the hierarchical tree of components and the performance increase induced.

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The antibiotic novobiocin2 has been shown to be 7-[4-(carbamoyloxy)-tetrahydro-3-hydroxy-5-methoxy-6,6-dimethylpyran-2-yloxy]-4-hydroxy-3-[4-hydroxy-3-(3-methyl-2-butenyl)-benzamido]-8-methylcoumarin (I).Novobiocin, elaborated by Streptomyces niveus, is a crystalline, acidic antibiotic of the composition CíiHmN,Ou. Studies on the fermentation,3-4 extraction, purification and properties,3 456•6 biological activity7 and clinical usefulness8 have been reported.Because of its interesting antibacterial action and its clinical efficacy, the structure of novobiocin is of particular significance. Evidence is presented in this paper to show that novobiocin possesses structure I. O ocnh2 oh ch3 I General Characteristics.-Novobiocin crystallized in two polymorphic modifications, one melting at 174-178°and the other at 152-1560.6-6 The dibasic acid properties of the compound were indicated by the preparation of both acid and neutral salts. Potentiometric titrations and ultraviolet spectral shifts confirmed these observations and showed novobiocin to be a dibasic acid with pK'& values of 4.3 and 9.1 in aqueous solution. The ultraviolet spectra in acid, neutral and alkaline solu-(1) Novobiocin.IV. The investigations upon which this paper is based were first reported in a series of preliminary communications. (a) (This Journal, 77, 6710 (1955); (b) 78, 1072; (c) 78, 2019 (1956)). These findings are in agreement with those reported independently by the Merck group (d) (ibid., 78, 1770 (1956)).(2) The Upjohn Co. Registered Trademark for novobiocin is Albamycin. Our former generic name, streptonivicin, has been aban-(3) C.