2016 Volume 24 Issue 2 Pages 266-274
In order to realize highly-reliable volunteer computing (VC), this paper develops a VC system with credibility-based voting. Credibility-based voting is known as an efficient technique for eliminating incorrect calculation results returned by participant (worker) nodes. Although its theoretical performance has been studied in detail, its implementation and practical performance have not been fully studied yet. Our VC system consists of a management server and a number of worker nodes. In the management server, each process that includes credibility-based voting is multithreaded, and all information is managed in a database for high performance and stable operation. Through performance evaluations, we found that the most time-consuming processes are the credibility-based voting in a network environment with a small delay (e.g., Intranet), and the process for sending jobs in a network environment with a moderate delay (e.g., domestic Internet). Moreover, multithreading is shown to be effective for those performance bottlenecks, and feasible system configurations are also revealed for a variety of request rates.