Patent ID: 8645319

Claim:
An information processing system comprising: a first information processing unit for managing an original database constituting a mass of data; and a plurality of second information processing units, each of the plurality of second information processing units managing a respective duplicate database, of a plurality of duplicate databases, each respective duplicate database constituting a duplicate of the original database, wherein an update log storing update information generated in the original database of the first information processing unit is transmitted to each of the plurality of second information processing units and reflected in each of the respective duplicate databases, wherein each of the plurality of second information processing units includes: a request processing unit, which upon acceptance of an update request from an external computer, that is not the first information processing unit or any of the plurality of second information processing units, transmits the update request to the first information processing unit to update the original database while at the same time updating each of the respective duplicate databases of each of the plurality of second information processing units; an update information management unit for checking, for each data in each of the respective duplicate databases, whether the update log corresponding to the update request accepted from the external computer is received from the first information processing unit or not; and an update reflection determination unit, which upon acceptance of a new update log from the first information processing unit, makes a determination of whether the new update log is newer than the update request accepted from the external computer, based on the information stored in the new update log and the information managed by the update information management unit, and reflects the update content of the new update log in each of the respective duplicate databases, when, as a result of the determination, the new log is newer than the update request accepted from the external computer.