Reliability Consideration of a Remote Data Replication for Disaster Recovery

摘要

As the Information technology has remarkably developed, a business data has been accumulated in a server. It is fatal for a business to lose the data by a disaster such as earthquake, typhoon, fire disaster, electricity failure and so on. In order to avoid the data loss and the stagnation of a business operation by a disaster, remote replication using network link has been adopted. This paper considers the problem of reliability in a server system with remote replication for the disaster recovery. We formulate a stochastic model of a server system which consists of a monitor, a main site and a backup site. The backup site stands by alert for a disaster. The main site performs the routine work and updates the storage database when a client requests the data update. The server in the main site transmits the database content to a backup site through networks. It is called replication. We derive the expected number of the replication and the probability of migrating routine work to the backup site, and so on. Further, we calculate the expected costs and discuss ways to minimize it. Finally, numerical examples are given.