Patent ID: 6466950
Filing Date: 2002-10-15
Classification: G06F,Y10S

Abstract:
An update log management device used in a data sharing system for maintaining and storing a data replicated among a plurality of devices connected in a network, comprising:a storage for recording a plurality of update logs wherein each one of the plurality of update logs shows an update of the data; an extracting unit for extracting at least one of update logs from the plurality of update logs stored in the storage to transmit to another device to maintain the identical data among the plurality of devices; a comparing unit for calculating data amount X which is an addition of data amount of the at least one of update logs for transmitting to the another device extracted by the extracting unit, and for calculating data amount Y which is an addition of data amount of the data itself plus data amount of log applied information indicating that the at least one of update logs is already applied to the data itself, and for comparing the data amount X and the data amount Y; a transmitting unit for transmitting the data itself and the information indicating that the at least one of update logs is already applied to the data to the another device if the data amount X of the at least one of update logs exceeds the data amount Y (X>Y), and for transmitting the at least one of update logs to the another device if the data amount X of the at least one of update logs does not exceed the data amount Y (X&lE;Y); and a deleting unit for deleting the at least one of update logs from the storage if X>Y is true for all of the devices.