METHOD AND APPARATUS FOR PERFORMING CHAGE-OVER CONTROL TO PROCESSOR GROUPS BY USING RATE OF FAILED PROCESSORS IN A PARALLEL COMPUTER

In a change-over control method for a parallel processor system including a current processor group having a plurality of processors and a network connecting the processors to each other and a standby processor group configured in the same way as for the current processor group, a processor control section is disposed in the parallel processor system, and a monitor processor is arranged for each of the current and standby processor groups. A faulty processor ratio determined according to the amount of job processing is set to the processor control section. On receiving a report notifying occurrence of a failure in a processor from the monitor processor disposed in the current processor group, the processor control section determines a ratio of failed processors in the current processor group. When the ratio is equal to or more than the faulty processor ratio, the processor control section effects a change-over operation of transferring job processing from the current processor group to the standby processor group.