1. Field of the Invention
The present invention relates, in a processing system having a plurality of CPUs each executing an online control program, to a method of recovering the failure of the online control program.
2. Description of the Prior Art
A prior-art method of recovering the failure of an online control program at high speed is called the "hot standby recovery method." With this method, in correspondence with the online control program, a standby program is previously prepared in a state in which the process of the preceding stage of a recovery process for the failure has been completed, and the recovery process is performed with the standby program at the failure of the online control program, thereby to shorten the recovery period of time.
The official gazette of Japanese Patent Application Laid-open No. 11457/1984, etc. are relevant to the technique of this type.
The hot standby recovery method in the prior art has had the following problems since the redundant construction in which the standby program is prepared separately from the online control program is employed, at the failure of the online control program, a service cannot be started until the recovery process with the standby program is completed. Further the online control program cannot be recovered at high speed in a case where it has failed after the failure of the standby program.