Search

In distributed databases for general-purpose business software, such as groupware, the asynchronous replication update method is widely employed to assure coincidence in the contents of the database; the replications of other databases retained in each database are updated simultaneously according to a predetermined schedule. This article discusses the approximate scheduling in such a distributed database that minimizes the communications cost of updating the replications. More precisely, as the first step, we consider the case in which two-way concurrent transmission is allowed in each link, and the communications cost is proportional to the communication time required for the transfer. The problem of deriving the schedule to minimize the communications cost is formulated. As a practical method of solving that problem, a heuristic method that effectively derives the approximate schedule with a communications cost close to the minimum is proposed. A quantitative evaluation of the proposed method is presented, and it is shown that a schedule very close to the optimal solution is obtained if the communications cost coefficient of the links is almost the same. © 1999 Scripta Technica, Electron Comm Jpn Pt 1, 83(1): 73–86, 2000 [ABSTRACT FROM AUTHOR]