Multicomputers are expensive resources that must be shared among multiple users to achieve the desired levels of throughput, utilization, and price-performance ratio. A multi-user environment may be provided either by space partitioning, or time-sharing, or a combination of both. This dissertation presents fast and efficient techniques to improve the performance of multi-user multicomputers using both space partitioning as well as 'time-sharing on space partitions' approaches. The techniques have been specifically targeted for mesh and hypercube multicomputers; the two popular topologies for commercial multicomputers. Space partitioning deals with executing independent tasks on independent partitions. It comprises of two components: the processor allocator and the job sequencer. This dissertation presents fast and efficient strategies for processor allocation in mesh and hypercubes. Simulation results demonstrate that the proposed strategies outperform all the existing methods in terms of the response times while possessing the least time and space overheads. The strategies proposed for job sequencing are independent of the topology and improve the turn-around times of jobs significantly. In addition, they are shown to efficiently utilize the proposed processor allocation strategies. This results in an improved performance and low space and time overheads. Time-sharing on space partitions possesses a promising prospect for improving the response times of users while providing an interactive service. A subcube level time-sharing strategy has been proposed for hypercube multicomputers. The proposed strategy tries to allocate overlapping subcubes to incoming tasks where each processor is time-shared between the various processes running on it. The proposed strategy was implemented on a 64 node nCUBE 2E system running real applications. The proposed strategy is shown to outperform both the space partitioning and the time-sharing approaches.
| Identifer | oai:union.ndltd.org:UMASS/oai:scholarworks.umass.edu:dissertations-9053 |
| Date | 01 January 1995 |
| Creators | Das Sharma, Debendra |
| Publisher | ScholarWorks@UMass Amherst |
| Source Sets | University of Massachusetts, Amherst |
| Language | English |
| Detected Language | English |
| Type | text |
| Source | Doctoral Dissertations Available from Proquest |
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