Hot standby system and hot stand-by manner

摘要

PPROBLEM TO BE SOLVED: To provide a hot standby method for shifting control from a master system to a standby system while continuing communication with a slave system. PSOLUTION: The slave system outputs the same data to the master system and the standby system. The master system outputs data for the slave system with an index attached thereto to the slave system. The standby system writes, to a buffer, data same as the data which is output from the master system to the slave system, with an index same as the index attached to the data by the master system. When the master system fails, the slave system outputs an operation request to the standby system together with the index immediately before the failure. When the standby system receives the operation request, the standby system outputs data with the index immediately after the input index and subsequent data, to the slave system. PCOPYRIGHT: (C)2010,JPO&INPIT