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See detailOn the Resilience of [distributed] Evolutionary Algorithms against Cheaters in Global Computing Platforms
Varrette, Sébastien UL; Tantar, Emilia UL; Bouvry, Pascal UL

in Proc. of the 14th Intl. Workshop on Nature Inspired Distributed Computing (NIDISC 2011), part of the 25th IEEE/ACM Intl. Parallel and Distributed Processing Symposium (IPDPS 2011) (2011)

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See detailCheating impact on distributed Evolutionary Algorithms over BOINC computations.
Varrette, Sébastien UL; Muszynski, Jakub UL; Bouvry, Pascal UL

in n Proc. of the 19th Intl. conference on Security and Intelligent Information Systems (SIIS 2011) (2011)

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See detailCertiCloud: une plate-forme Cloud IaaS sécurisée
Bertholon, Benoit UL; Varrette, Sébastien UL; Bouvry, Pascal UL

in RenPar'20 2011 (2011)

La sécurité des Clouds est un aspect essentiel qui n'est pas forcément abordé selon le point de vue de l'utilisateur. En particulier, sur une plate-forme de type IaaS, il est actuellement impossible pour ... [more ▼]

La sécurité des Clouds est un aspect essentiel qui n'est pas forcément abordé selon le point de vue de l'utilisateur. En particulier, sur une plate-forme de type IaaS, il est actuellement impossible pour un utilisateur de certifier de manière fiable et sécurisée que l'environnement qu'il a déployé (typiquement sous forme d'une machine virtuelle) est toujours dans un état qu'il juge intègre et opérationnel. Cet article s'attelle à cette tâche en proposant CertiCloud, une plate-forme Cloud de type IaaS qui exploite les concepts développés dans le cadre du TCG mais aussi les éléments matériels que sont les TPM pour offrir à l'utilisateur un environnement sécurisé et sécurisant. Ces deux aspects sont garantis par les deux protocoles TCRR et VerifMyVM qui sont à la base de CertiCloud. Quand le premier permet de certifier l'intégrité d'une machine distante et d'échanger une clef de chiffrement symétrique, le second permet à l'utilisateur de s'assurer dynamiquement et à la demande de l'intégrité de sa machine virtuelle exécutée sur les ressources de \CertiC. Ces deux protocoles étant les briques de base de notre plate-forme, une attention toute particulière a été apportée à leurs élaborations. A cet effet, ils ont été validés avec succès par AVISPA et Scyther, deux outils de référence dans le domaine de la vérification automatique des protocoles de sécurité (cette analyse est présentée dans cet article). Ensuite, la plate-forme CertiCloud est détaillée: outre les protocoles TCRR et VerifMyVM, elle propose le stockage sécurisé des environnements utilisateurs et leurs exécutions à travers un framework de virtualisation reprenant l'hyperviseur Xen. Quand les ressources physiques sont certifiées par TCRR, l'utilisateur peut utiliser à la demande le protocole VerifMyVM pour s'assurer de l'intégrité de son environnement déployé. Un prototype de CertiCloud a été réalisé et nous présentons les premiers résultats expérimentaux qui démontrent de la faisabilité et du faible surcoût de notre approche sur des scénarios classiquement rencontrés sur les infrastructures Cloud de type IaaS. [less ▲]

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See detailOn the Resilience of [Distributed] EAs against Cheaters in Global Computing Platforms
Varrette, Sébastien UL; Tantar, Emilia UL; Bouvry, Pascal UL

in 25th IEEE International Symposium on Parallel and Distributed Processing (IPDPS 2011) (2011)

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See detailchap. "Practical Security in Distributed Systems"
Bertholon, Benoit UL; Cérin, C.; Coti, C. et al

in Distributed Systems (volume 1); Design and Algorithms (2011)

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See detailPractical Security in Distributed Systems
Bertholon, Benoit UL; Cérin, Christophe; Coti, Camille et al

in Haddad, S.; Kordon, F.; Pautet, L. (Eds.) et al Distributed Systems; Design and Algorithms, 1 (2011)

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See detailDeskilling HPL - Using an Evolutionary Algorithm to Automate Cluster Benchmarking
Dunlop, Dominic UL; Varrette, Sébastien UL; Bouvry, Pascal UL

in Proc. of 8th Intl. conf. on Parallel Processing and Applied Mathematics (PPAM 2009) (2009, September), 6068(LNCS), 102--114

The High-Performance Linpack (HPL) benchmark is the ac- cepted standard for measuring the capacity of the world’s most powerful computers, which are ranked twice yearly in the Top 500 List. Since just a ... [more ▼]

The High-Performance Linpack (HPL) benchmark is the ac- cepted standard for measuring the capacity of the world’s most powerful computers, which are ranked twice yearly in the Top 500 List. Since just a small deficit in performance can cost a computer several places, it is impor- tant to tune the benchmark to obtain the best possible result. However, the adjustment of HPL’s seventeen configuration parameters to obtain maximum performance is a time-consuming task that must be performed by hand. In a previous paper, we provided a preliminary study that proposed the tuning of HPL parameters by means of an Evolutionary Algorithm. The approach was validated on a small cluster hosted at the University of Luxembourg. In this article, we extend this initial work by describing Acbea, a fully-automatic benchmark tuning tool that performs both the configuration and installation of HPL followed by an automatic search for optimized parameters that will lead to the best benchmark results. Experiments have been conducted to validate this tool on several clusters, exploiting in particular the Grid’5000 infrastructure. [less ▲]

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See detailUne approche génétique et source à source de l'optimisation de code
Guelton, S.; Varrette, Sébastien UL

Scientific Conference (2009, September)

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See detailParallel implementation of domain decomposition algorithm for molecular dynamics
Berhe, Girma UL; Peters, Bernhard UL; Varrette, Sébastien UL et al

in PARENG 2007 (2009)

The objective of this study is to apply a domain decomposition algorithm to the La- grangian based Discrete Particle Method (DPM). The latter deals with the thermal decomposition of solid e.g. biomass ... [more ▼]

The objective of this study is to apply a domain decomposition algorithm to the La- grangian based Discrete Particle Method (DPM). The latter deals with the thermal decomposition of solid e.g. biomass fuel particles. It considers each particle as an individual entity that is represented by an instantiation of a class. Modelizing thermal conversion of biomass in real systems involves a large number of particles. This can be achieved in a reasonable computing time only through a parallel implementation able to distribute the particles e.g. objects onto the participating processors. This pa- per present such an implementation based on Orthogonal Recursive Bisection (ORB) method. Due to the fact that the particles may take arbitrary positions within the do- main, a particular issue addressed by the domain decomposition technic used in this work is to generate a load balance for each processors as uniform as possible. Fur- thermore, the particles are coupled via heat transfer. One challenge for the designed algorithm is then to identify the nearest neighbours of each particle so that the nec- essary information can be communicated between them. Since the positions of all particles are subject to change and may migrate from one processor to another, the communication links together with the number of neighbors are highly dynamic. The implementation is carried out using the KAAPI API, a C++ library for parallel pro- gramming that allows to execute ?ne/medium grain multithreaded computation with dynamic data ?ow synchronizations. First results are very promising since they indi- cate that our algorithm creates sub domains with an average imbalance ranging from 2.5% to 6.3% for uniformly distributed particles. [less ▲]

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See detailDynamic Adaptation Applied to Sabotage Tolerance
Guelton, S.; Gautier, T.; Pazat, J.-L. et al

in Proc. of the IEEE 17th Euromicro International Conference on Parallel, Distributed, and Network-Based Processing (PDP 2009) (2009)

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See detailNature inspired Algorithm-Based Fault Tolerance on Global Computing Platforms. Application to Symbolic Regression
Varrette, Sébastien UL; Ostaszewski, Marek UL; Bouvry, Pascal UL

in International Conference on Metaheuristics and Nature Inspired Computing (META'08) (2008)

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See detailOn the Use of a Genetic Algorithm in High Performance Computer Benchmark Tuning
Dunlop, Dominic UL; Varrette, Sébastien UL; Bouvry, Pascal UL

in IEEE International Symposium on Performance Evaluation of Computer and Telecommunication Systems (SPECTS'08) (2008)

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See detailResult Certification Against Massive Attacks in Distributed Computations
Varrette, Sébastien UL; Roch, Jean-Louis; Krings, Axel

Scientific Conference (2008)

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See detailBuilding Secure Resources to Ensure Safe Computations in Distributed and Potentially Corrupted Environments
Varrette, Sébastien UL; Roch, Jean-Louis; Duc, Guillaume et al

in Euro-Par 2008, Workshop on Secure, Trusted, Manageable and Controllable Grid Services (SGS'08) (2008)

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See detailchapt. Sécurité dans les grilles de calcul,
Cérin, C.; Dubacq, J.-C.; Hérault, T. et al

in Systèmes répartis en action : de l'embarqué aux systèmes à large échelle (2008)

Detailed reference viewed: 51 (1 UL)
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See detailSécurité dans les grilles de calcul
Cérin, Christophe; Dubacq, Jean-Christophe; Hérault, Thomas et al

in Kordon, F.; Pautet, L.; Petrucci, L. (Eds.) Systèmes répartis en action: de l'embarqué aux systèmes à large échelle (2008)

Detailed reference viewed: 77 (1 UL)