Reducing power consumption in cluster system of mutual standby type

A cluster system of mutual standby type configured to form groups each composed of a job execution system, and a job standby system for taking over the job when problems occur in the job execution system;

• and provide information processing devices each with a job execution system and a job standby system of different groups, wherein the information processing devices monitor one another while carrying out the jobs of the execution systems and, when some other information processing device becomes unable to continue processing, take over that job with the job standby system of its own information processing device in the same group as the job execution system of the other information processing device unable to continue processing, the information processing devices each comprising:
• an upper limit value storage unit for storing a power upper limit value;
• a power control unit for controlling the use of power by its own information processing device so as not to exceed the power upper limit value stored in the upper limit value storage unit;
• and
• an upper limit value setting unit for causing the upper limit value storage unit to store a power upper limit value smaller than the maximum power consumption of its own information processing device when it is not necessary to take over the job of another information processing device.