Patent ID: 8214823

Claim:
A cluster system performing distributed processing by use of a plurality of servers, comprising a service provision node and a monitoring node; said service provision node includes, an execution unit which executes processing according to a processing request when the service provision node receives the processing request, and stops operation of the execution unit when the execution unit receives a command to stop the execution unit, and a heartbeat transmission unit which periodically transmits first heartbeat packets containing interval information to the monitoring node at first intervals when the execution unit is in operation, transmits a second heartbeat packet containing interval information to the monitoring node when the heartbeat transmission unit receives the command to stop the execution unit, and restarts periodical transmission of the first heartbeat packets when the execution unit is restarted, where the interval information contained in the first heartbeat packets indicates the first intervals, and the interval information contained in the second heartbeat packet indicates a second interval greater than the first intervals; and said monitoring node includes, an interval storage which stores in correspondence with the service provision node the interval information contained in the first heartbeat packets or the second heartbeat packet, an interval updating unit which receives each of the first heartbeat packets and the second heartbeat packet transmitted from the service provision node, and updates the interval information stored in the interval storage in correspondence with the service provision node, with the interval information contained in said each of the first heartbeat packets and the second heartbeat when the interval information contained in said each of the first heartbeat packets and the second heartbeat is different from the interval information stored in the interval storage in correspondence with the service provision node, and a heartbeat monitoring unit which determines that the execution unit is in operation, while the monitoring node receives said first heartbeat packets and said second heartbeat packet at intervals indicated by the interval information stored in the interval storage in correspondence with the service provision node.