| 摘要 |
PROBLEM TO BE SOLVED: To provide a technique for keeping data in all data management devices in the same condition according to information from a newly selected master when a distributed data management system comprising a plurality of data management devices enters a multi-master state, the system being such that one of the data management devices operates as a master while the remaining data management devices operate as replicas maintaining the same data state as the master.SOLUTION: When the system enters the multi-master state, master arbitration is performed, and if a new master (replica R4) is selected, a master generation number is updated because the replica R4 corresponds to a case in which a new master is selected and in which the newly selected master differs from the old master. When replicas R2, R3 receive Propose including the same agenda number "100" from the old master (database device 10A) and the new master (replica R4), a log update and a block update are performed according to the replica with the greater master generation number. |
