Failover to a standby system calculator in the loss of communication between currently-used system calculator and standby system calculator

摘要

A standby system calculator communicates with a currently-used system calculator for retaining data about a service, providing the service by using the data, and updating the data along with provision of the service. The standby system calculator includes a retainer that retains a copy of the data and a provider that provides the service by using the copy of the data while restricting an updating operation for updating the copy of the data in the retainer when a predetermined signal that indicates that the currently-used system calculator is operating and that has been transmitted from the currently-used system calculator to the standby system calculator, cannot be received for a predetermined period of time.

主权项

1. A standby system calculator that communicates with a currently-used system calculator for retaining data about a service, said currently-used system calculator providing the service by using the data, and said currently-used system calculator updating the data along with a provision of the service, the standby system calculator comprising:
a retention unit that retains a copy of the data; and a provision unit that provides the service by using the copy of the data while restricting an updating operation for updating the copy of the data in said retention unit when the provision unit does not receive a predetermined signal transmitted from the currently-used system calculator to the standby system calculator for a predetermined period of time, said predetermined signal indicating that the currently-used system calculator is operating, wherein when said provision unit receives an instruction to cancel the restriction on the updating operation after providing the service, said provision unit cancels the restriction on the updating operation and provides the service by using the copy of the data, and wherein said instruction is received after a failover is carried out.