Browsing by Author "Koelbel, Charles"

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    Scalable Grid Application Scheduling via Decoupled Resource Selection and Scheduling
    (2006-01-20) Casanova, Henri; Chien, Andrew A.; Kee, Yang-Suk; Kennedy, Ken; Koelbel, Charles; Mandal, Anirban; Zhang, Yang
    Over the past years grid infrastructures have been deployed at larger and larger scales, with envisioned deployments incorporating tens of thousands of resources. Therefore, application scheduling algorithms can become unscalable (albeit polynomial) and thus unusable in large-scale environments. One reason for unscalability is that these algorithms perform implicit resource selection. One can achieve better scalability by performing explicit resource selection decoupled from scheduling (aka "decoupled" approach). Furthermore, we hypothesize that one can achieve similar or even better performance as with the non-decoupled approach (aka "one step" approach) by selecting resources judiciously. Leveraging the Virtual Grid Execution System, we demonstrate that the decoupled approach is indeed both scalable and effective in large-scale and highly heterogeneous resource environments.
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    Scheduling Algorithms Performance Evaluation in Grid Environments
    (2006-04-18) Kennedy, Ken; Koelbel, Charles; Zhang, Yang
    Effective scheduling is critical for the performance of an application launched onto the Grid environment. Deriving efficient algorithms for this scheduling has always been a challenging research area. Many scheduling algorithms have been proposed, studied and compared but there are few studies comparing their performance in Grid environments. The Grid environment has the unique property of drastic cost differences between inter-cluster and the intra-cluster data transfers. In this paper, we compare several scheduling algorithms that represent two major schemes. We further analyze the results to show how different resource environments and workflow application structures affect the algorithms' performances, and suggest directions for future research in Grid schedulers.