Patent ID: 8332506

Claim:
A computer-readable, non-transitory medium storing a network monitor program for causing a computer included in a cluster system to execute a network monitoring processing, said network monitor processing comprising: after transmitting a first message to a relay apparatus, which is connected with other computers included in the cluster system and relays a request to said computer, and detecting that said computer did not receive a response to the first message from the relay apparatus, obtaining status data of said other computers included in said cluster system; in response to detecting that said status data of said other computers represents that one of said other computers is in a usable state, causing, by said computer, said one of said other computers, which is in the usable state, to send a second message to said relay apparatus, and receiving, from said one of said other computers, a result representing whether or not said one of said other computers received a response to said second message sent by said one of said other computers from said relay apparatus; and in response to receiving, from said one of said other computers, said result representing that said one of said other computers received said response to said second message from said relay apparatus, notifying a cluster manager of an occurrence of a communication failure.