A Scheduling Method of Database Migration for WAN Environments

In broadband networks, appropriate use of database migration can drastically shorten the average transaction processing time of a distributed database system. In previous work, we have proposed a transaction processing method based on database migration, a method in which we assumed that the network bandwidth is very broad and almost uniform over the whole network. However, WANs consist of various types of networks, including private LANs, narrowband public networks and broadband backbones; thus, it is di cult to control database migration in the granularity of the transaction and to execute database migration through networks other than backbones. Therefore, that method cannot be applied directly in WAN environments. In this paper, we propose a database migration scheduling method which is suitable for use in such heterogeneous WANs. We also discuss one method of implementation our proposed scheduling method in a practical environment. keywords: database migration, WAN (Wide Area Network), broadband network, distributed database