Design Changes to the COPAR Service using Opnet Modeler

Rhea L. Seegobin, Michael A. Hosein, Joel M. Crichlow, and Stephen J. Hartley


COPAR, opnet modeler, parallel threads


The COPAR service has been converted from a Java- based, Internet, distributed system into an Opnet Modeler simulation. The system was expanded from eight nodes to a maximum of 100 nodes. The system was implemented in five simulation sizes; 20, 40, 60, 80 and 100 nodes. The COPAR Service in Opnet still uses optimistic and pessimistic techniques to process transactions. The functionality of the system was not compromised; however the design of the service has changed. These changes will be discussed in detail in this paper. Additional functionality such as parallel thread processing, mutual exclusion and the development of node and process models are included in this design of the COPAR Service. The previous system provided automatic mutual exclusion and parallel threading services using Java’s API. In the converted system the developer was required to implement this manually since Opnet does not provide mutual exclusion [6]. In [6], many challenges were discussed to make this conversion a success. These challenges also led to major, but necessary design changes for this service. This paper helps to understand the design changes that the COPAR Service has undergone. This paper can also assist researchers to design new systems and remodel existing ones.

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