Performing calculation for state management when failure in communication has occurred

A communication system comprising:

• a plurality of communication apparatuses that form a network;
• and
• a management apparatus that is connected to at least one of the plurality of communication apparatuses and manages states of the plurality of communication apparatuses, wherein
• the communication apparatus comprises:
• hardware, including a processor and memory storing instructions executable by the processor to:
• communicate with a management apparatus that manages states of a plurality of communication apparatuses of a network directly or via another communication apparatus;
• when a failure in communication has not occurred at a side of the management apparatus, transfer to the management apparatus a state change notification transmitted from a first communication apparatus located on the side of the management apparatus, and indicate a state change in the first communication apparatus, by relaying communication between the management apparatus and the first communication apparatus, wherein the state change notification is transferred to the management apparatus so that the management apparatus performs a calculation for state management using the state change notification, such that the communication apparatus does not perform the calculation when the failure has occurred;
• when the failure in communication has occurred, perform the calculation for the state management that would ordinarily and otherwise performed by the management apparatus but that cannot be performed by the management apparatus due to the state change notification not being transferred to the management apparatus, using the state change notification, and output the state change notification without transferring the state change notification to the management apparatus;
• when the failure in communication has occurred and once the failure has been resolved, transmit a result of the calculation to the management apparatus.

A communication method that is performed by a communication apparatus, the communication method comprising:

• communicating with a management apparatus that manages states of a plurality of communication apparatuses of a network directly or via another communication apparatus;
• when a failure in communication has not occurred at a side of the management apparatus, transferring to the management apparatus a state change notification transmitted from a first communication apparatus located on the side of the management apparatus, and indicating a state change in the first communication apparatus, by relaying communication between the management apparatus and the first communication apparatus, wherein the state change notification is transferred to the management apparatus so that the management apparatus performs a calculation for state management using the state change notification, such that the communication apparatus does not perform the calculation when the failure has occurred;
• when the failure in communication has occurred, performing the calculation for state management that is ordinarily and otherwise performed by the management apparatus but that cannot be performed by the management apparatus due to the state change notification not being transferred to the management apparatus, using the state change notification, and outputting the state change notification without transferring the state change notification to the management apparatus;
• when the failure in communication has occurred and once the failure has been resolved, transmitting a result of the calculation to the management apparatus when the failure in communication.

A non-transitory computer readable medium storing a program for causing a computer to execute:

• communicating with a management apparatus that manages states of a plurality of communication apparatuses of a network directly or via another communication apparatus;
• when a failure in communication has not occurred at a side of the management apparatus, transferring a state change notification transmitted from a first communication apparatus located on the side of the management apparatus, and indicating a state change in the first communication apparatus, by relaying communication between the management apparatus and the first communication apparatus;
• when the failure in communication has occurred, performing a calculation for state management performed by the management apparatus using the state change notification, and outputting the state change notification without transferring the state change notification to the management apparatus;
• when the failure in communication has occurred and once the failure has been resolved, transmitting a result of the calculation to the management apparatus when the failure in communication.