US Patent 7756994 Consistent information management among server devices

The present invention has an object of managing information without generating any inconsistency between a plurality of servers. A server system according to the present invention includes a plurality of server devices that perform processing using a plurality of processing data without duplication. Each of the server devices relays a signal initially transmitted by any of the server devices so that the signal passes through all the server devices to be finally received by the server device initially transmitting the signal, transmits a first signal indicating use of processing data to another server device when any of the processing data is to be used, receives the first signal from the another server device and relays it to a further another server device, and permits use of the processing data to be used when transmission means transmits the first signal and the first signal is relayed from one of the other server devices.