Scheduling multiple divisible loads on a linear processor network

Min, Veeravalli, and Barlas have recently proposed strategies to minimize the overall execution time of one or several divisible loads on a heterogeneous linear network, using one or more installments. We show on a very simple example that their approach does not always produce a solution and that, when it does, the solution is often suboptimal. We also show how to find an optimal schedule for any instance, once the number of installments per load is given. Then, we formally state that any optimal schedule has an infinite number of installments under a linear cost model as the one assumed in the original papers. Therefore, such a cost model cannot be used to design practical multi-installment strategies. Finally, through extensive simulations we confirmed that the best solution is always produced by the linear programming approach, while solutions of the original papers can be far away from the optimal

Comments on "Design and performance evaluation of load distribution strategies for multiple loads on heterogeneous linear daisy chain networks''

Min, Veeravalli, and Barlas proposed strategies to minimize the overall execution time of one or several divisible loads on a heterogeneous linear network, using one or more installments. We show on a very simple example that the proposed approach does not always produce a solution and that, when it does, the solution is often suboptimal. We also show how to find an optimal scheduling for any instance, once the number of installments per load is given. Finally, we formally prove that under a linear cost model, as in the original paper, an optimal schedule has an infinite number of installments. Such a cost model can therefore not be sed to design practical multi-installment strategies

Comments on "Design and performance evaluation of load distribution strategies for multiple loads on heterogeneous linear daisy chain networks''

Min, Veeravalli, and Barlas proposed strategies to minimize the overall execution time of one or several divisible loads on a heterogeneous linear network, using one or more installments. We show on a very simple example that the proposed approach does not always produce a solution and that, when it does, the solution is often suboptimal. We also show how to find an optimal scheduling for any instance, once the number of installments per load is given. Finally, we formally prove that under a linear cost model, as in the original paper, an optimal schedule has an infinite number of installments. Such a cost model can therefore not be sed to design practical multi-installment strategies.Min, Veeravalli, and Barlas ont proposé [8,9] des stratégies pour minimiser le temps d’exécution d’une ou de plusieurs tâches divisibles sur un réseau linéaire de processeurs hétérogènes, en distribuant le travail en une ou plusieurs tournées. Sur un exemple très simple nous montrons que l’approche proposée dans [9] ne produit pas toujours une solution et que, quand elle le fait, la solution est souvent sous-optimale. Nous montrons également comment trouver un ordonnancement optimal pour toute instance, quand le nombre de tournées par tâches est spécifié. Finalement, nous montrons formellement que lorsque les fonctions de coûts sont linéaires, comme c’est le cas dans [8,9], un ordonnancement optimal au n nombre infini de tournées. Un tel modèle de coût ne peut donc pas être utilisé pour définir des stratégies en multi-tournées utilisables en pratiqu

Optimizing Data Intensive Flows for Networks on Chips

Data flow analysis and optimization is considered for homogeneous rectangular mesh networks. We propose a flow matrix equation which allows a closed-form characterization of the nature of the minimal time solution, speedup and a simple method to determine when and how much load to distribute to processors. We also propose a rigorous mathematical proof about the flow matrix optimal solution existence and that the solution is unique. The methodology introduced here is applicable to many interconnection networks and switching protocols (as an example we examine toroidal networks and hypercube networks in this paper). An important application is improving chip area and chip scalability for networks on chips processing divisible style loads

Resource unaware load distribution strategies for processing divisible loads in networked computing environments

Ph.DDOCTOR OF PHILOSOPH

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

Ph.DDOCTOR OF PHILOSOPH

Design, analysis and application of divisible load scheduling strategies in linear daisy chain networks with system constraints

Ph.DDOCTOR OF PHILOSOPH

Scheduling Real-time Divisible Loads in Cluster Computing Environment

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

Design and analysis of load balancing/scheduling strategies on distributed computer networks using virtual routing approach

Ph.DDOCTOR OF PHILOSOPH