摘要 |
PURPOSE: A duplicated database management system for a main memory-resident DBMS is provided to process duplexing without an influence on the performance of a main memory-resident DBMS(Database Management System) by individually setting up two systems in the active state and the standby state and making the DBMS interlock with an external application software. CONSTITUTION: Two systems respectively have an active DBMS(110) and a standby DBMS(120). The active DBMS is connected with the standby DBMS via the Ethernet(103) to transmit and receive information. Each DBMS includes a detector(111,121) to detect the state of the DBMS and request the state change of two systems by using heartbeat information, an inquiry processor(112,122), a DBMS server(113,123) to write the memory DB change word and change history and to backup the change history in the disk DB, and a memory DB(114,124). The duplex manager is constituted of an independent thread to control agreement of two memory databases. The active DBMS transmits the log of the changed particulars to the standby DBMS, and the standby DBMS changes the operating information in the DBMS.
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