A computer system configured to be a cluster (multi-node cluster) system having multiple nodes (server machines) operates the multiple nodes connected to one another via a network such as a Local Area Network (LAN) in parallel with one another.
Such a recent cluster system is enduring an increased cost of consumption power in proportional to improvement in performance of network devices and also to an increase in data to be processed. Accordingly, higher demands arise to save power in a computing system.
A conventional computer system optimizes the performance thereof, maintaining entire amounts of heat and power of the system, by adjusting, for example, the voltage level to be applied to the processor.                [Patent Literature 1] Japanese Laid-open Patent Publication No. 2009-193385        [Patent Literature 2] Japanese Laid-open Patent Publication No. 2004-078940        
However, such a conventional computer system has difficulty in satisfying the performance demanded for the system and also in suppressing the consumption power when the working environment of the system is varied.
As one example, vibration may cause interference between nodes placed in the same rack or in contiguous racks and consequently the inter-node interference may degrade the performance of the system. As the above, in cases where the original performance of anode is largely damaged, the system performance degrades and/or the consumption power increases. Furthermore, the system performance is degraded and also the consumption power increases when a particular node fails to degrade the performance thereof and a node is active replaced in regular maintenance while the system is operating.