This dissertation is intended to explore the design of a dual connection skeleton (DCS), which facilitates effective and efficient exploitation of Internet-centric collaborative workgroup and high performance metacomputing applications. The predominant difference between DCS and conventional frameworks is that DCS administers a network of brokers that are grouped into a logical ring. New mechanisms for group collaboration, load distribution, and fault tolerance, which are three crucial issues in Internet-based computing, are proposed and integrated into the dual connection skeleton.
Collaborative workgroup becomes a significant common issue when we attempt to develop wide area applications supporting computer-supported cooperative work (CSCW). For group collaboration, DCS therefore offers a strategy for concurrency control that ensures the consistency of shared resources. By using the strategy, multiple users in a collaborative group are able to simultaneously access shared data without violating its consistency. With respect to load distribution, additionally, DCS applies an adaptive highest response ratio next (AHRRN) algorithm to job scheduling. Performance evaluations on competing algorithms, such as shortest job first (SJF), highest response ratio next (HRRN), and first come, first served (FCFS) are conducted. Simulation results demonstrate that AHRRN is not only an efficient algorithm, but also is able to prevent the well-known job starvation problem. In a parallel computational application, one can further decompose a composite job into constituent tasks such that these tasks can be assigned to different PEs for concurrent execution. The dual connection skeleton thus makes use of a proposed dynamic grouping scheduling (DGS), to undertake task scheduling for performance improvement. The DGS algorithm employs a task grouping strategy to determine computational costs of tasks. It re-prioritizes unscheduled tasks at each scheduling step to explore an appropriate task allocation decision. In terms of the schedule length, the performance of DGS has been evaluated by comparing with some existing algorithms, such as Heavy Node First (HNF), Critical Path Method (CPM), Weight Length (WL), Dynamic Level Scheduling (DLS), and Dynamic Priority Scheduling (DPS). Simulation results show that DGS outperforms these competing algorithms. Moreover, as for fault tolerance, DCS utilizes a dual connection mechanism for computational reliability enhancement. For the sake of constructing dual connection, we examine five approaches: RANDOM, NEXT, ROTARY, MINNUM, and WEIGHT. Each one of these approaches can be incorporated into DCS-based wide-area metacomputing systems. Performance simulation shows that WEIGHT benefits the dual connection the most. A DCS-based scientific computational application named the motion correction is used to demonstrate the fault tolerant ability of DCS. Putting the group collaboration, load distribution, and fault tolerance issues together, the dual connection skeleton forms a seamless and integrated framework for Internet-centric computing.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0813101-155034 |
| Date | 13 August 2001 |
| Creators | Chiang, Chuanwen |
| Contributors | Jen-Chih Yao, Chungnan Lee, C. S. Yang, Ce-Kuen Shieh, Chih-Ping Chu, Sing-Ling Lee, Ye-In Chang |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0813101-155034 |
| Rights | off_campus_withheld, Copyright information available at source archive |
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