697 research outputs found

    Scheduling Real-time Divisible Loads in Cluster Computing Environment

    Get PDF
    The significance of cluster computing in solving massively parallel workloads is tremendous. Divisible Load Theory has proven to be very successful in optimizing the usage of the system resources by partitioning the arbitrarily divisible loads adequately among the cluster nodes. Arbitrarily divisible loads have significant real-world applications in high energy and particle physics. In this thesis, various algorithms for a cluster computing environment are studied including the ones dealing with divisible load theory confirming DLT based algorithms performing better in most cases. The loads that are considered in this thesis are hard real-time tasks with associated deadlines. Specifically, a comparison is made between clusters with one where the head node doesn't participate in processing of the work-loads with the other where the head node does participate in processing of the work-loads. A new mathematical formula is derived for the task execution time corresponding to the new scenario of head node possessing front-end processing capability. The existing algorithms corresponding to Real-Time Divisible Load Theory are then implemented using this new formula to examine the scheduling performance in this new scenario compared to the conventional scenario where the head node lacks front-end processing capability

    Cost-aware real-time divisible loads scheduling in cloud computing

    Get PDF
    Cloud computing has become an important alternative for solving large scale resource intensive problems in science, engineering, and analytics. Resource management play an important role in improving the quality of service (QoS). This paper is concerned with the investigation of scheduling strategies for divisible loads with deadlines constraints upon heterogeneous processors in a cloud computing environment. The workload allocation approach presents in this paper is using Divisible Load Theory (DLT). It is based on the fact that the computation can be partitioned into some arbitrary sizes and each partition can be processed independently of each other. Through series of simulation against the baseline strategies, it can be found that the worker selection order in the service pool and the amount of fraction load assigned to each of them have significant effects on the total computation cost.Keywords: Cloud computing, Divisible Load Theory (DLT), Cost, Quality-of-service (QoS

    Static Scheduling Strategies for Heterogeneous Systems

    Get PDF
    In this paper, we consider static scheduling techniques for heterogeneous systems, such as clusters and grids. We successively deal with minimum makespan scheduling, divisible load scheduling and steady-state scheduling. Finally, we discuss the limitations of static scheduling approaches

    REQUIREMENT- AWARE STRATEGIES FOR SCHEDULING MULTIPLE DIVISIBLE LOADS IN CLUSTER ENVIRONMENTS

    Get PDF
    Ph.DDOCTOR OF PHILOSOPH

    Independent and Divisible Task Scheduling on Heterogeneous Star-shaped Platforms with Limited Memory

    Get PDF
    In this paper, we consider the problem of allocating and scheduling a collection of independent, equal-sized tasks on heterogeneous star-shaped platforms. We also address the same problem for divisible tasks. For both cases, we take memory constraints into account. We prove strong NP-completeness results for different objective functions, namely makespan minimization and throughput maximization, on simple star-shaped platforms. We propose an approximation algorithm based on the unconstrained version (with unlimited memory) of the problem. We introduce several heuristics, which are evaluated and compared through extensive simulations. An unexpected conclusion drawn from these experiments is that classical scheduling heuristics that try to greedily minimize the completion time of each task are outperformed by the simple heuristic that consists in assigning the task to the available processor that has the smallest communication time, regardless of computation power (hence a "bandwidth-centric" distribution).Dans ce rapport, nous nous intéressons au problème de l’allocation d’un grand nombre de taches indépendantes et de taille identiques sur des plateformes de calcul hétérogènes organisées en étoile. Nous nous intéressons également au modèle des tâches divisibles. Pour ces deux modèles, nous prenons en compte les contraintes mémoires et démontrons des résultats de NP-complétude pour diverses métriques (le «makespakan» et le débit). Nous proposons un algorithme d’approximation basé sur la version non-contrainte (c’est-`a-dire avec une mémoire infinie) du problème. Nous proposons également d’autres heuristiques que nous évaluons à l’aide d’un grand nombre de simulations. Une conclusion inattendue qui ressort de ces expériences est que les heuristiques de listes classiques qui essaient de minimiser gloutonnement la durée de l’ordonnancement sont bien moins performantes que l’heuristique toute simple consistant à envoyer les tâches aux processeurs disponibles ayant le temps de communication le plus faible, sans même tenir compte de leur puissance de calcu

    Coordinated workload scheduling in hierarchical sensor networks for data fusion applications

    Get PDF
    2007-2008 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe

    Dimensionerings- en werkverdelingsalgoritmen voor lambda grids

    Get PDF
    Grids bestaan uit een verzameling reken- en opslagelementen die geografisch verspreid kunnen zijn, maar waarvan men de gezamenlijke capaciteit wenst te benutten. Daartoe dienen deze elementen verbonden te worden met een netwerk. Vermits veel wetenschappelijke applicaties gebruik maken van een Grid, en deze applicaties doorgaans grote hoeveelheden data verwerken, is het noodzakelijk om een netwerk te voorzien dat dergelijke grote datastromen op betrouwbare wijze kan transporteren. Optische transportnetwerken lenen zich hier uitstekend toe. Grids die gebruik maken van dergelijk netwerk noemt men lambda Grids. Deze thesis beschrijft een kader waarin het ontwerp en dimensionering van optische netwerken voor lambda Grids kunnen beschreven worden. Ook wordt besproken hoe werklast kan verdeeld worden op een Grid eens die gedimensioneerd is. Een groot deel van de resultaten werd bekomen door simulatie, waarbij gebruik gemaakt wordt van een eigen Grid simulatiepakket dat precies focust op netwerk- en Gridelementen. Het ontwerp van deze simulator, en de daarbijhorende implementatiekeuzes worden dan ook uitvoerig toegelicht in dit werk
    corecore