| 摘要 |
PURPOSE:To quickly switch a system to restart business by providing a general inter- system communication path with a mechanism to which the number of retries can be set and variably setting the number of retries by software in accordance with the performance and the degree of multiplexing of the inter-system communication path to detect the system down of the host of the current system within a prescribed time. CONSTITUTION:A host 2 of the stand-by system sets such number of retries that the system down of the host of the current system can be detected in the prescribed time. A control program 21 is provided to control the system as follows; a patrol message command is sent to a retry control mechanism 5 or 6 of one inter-system communication path; and if a response does not come from a host 1 of the current system though the retry control mechanism 5 or 6 retries by the set number of retries, the patrol message command is sent to the retry control mechanism 6 or 5 of the other inter- system communication path; and if a response does not come from the host 1 of the current system though the retry control mechanism 6 or 5 retries by the set number of retries, system switching is performed by the host 2 of the stand-by system. Since the number of retries is variably set, excessive retries are avoided and the system down of the host 1 of the current system is detected within the prescribed time. |
