A new replication strategy for unforeseeable disconnection under agent-based mobile computing system

The goals of this paper are to revise previous replication strategies and propose a new hierarchy structure, client-agent-server architecture, to fit a mobile computing system that has more resource constraints than a conventional distributed database system has. This three-tier agent-based mobile computing system frees the limitations on time and whereabouts of computing. Moreover, a new replication strategy, three-copy replication that is based on an optimistic replication strategy, is proposed to deal with the problems of mobility management and disconnection management in a mobile computing system. It allows mobile clients to read and update the database while they are disconnected from the network, if the mobile copy is available. In addition, the implementation issues of this new replication strategy are also provided.