Abstract: A storing unit stores therein contract information indicating, with respect to each of a plurality of devices rented to a user and included in a system, an expiration time point at which a rental contract of each of the plurality of devices expires and communication channel information indicating inter-device communication channels between the plurality of devices. A processing unit determines, based on the contract information and the communication channel information, a second device to experience effect of expiration of the rental contract of a first device at a first time point amongst the plurality of devices, and outputs information indicating the effect on the second device.

Abstract: A data center includes a server, which hosts a plurality of virtual machines, and an information processing device. The information processing device is configured to receive from a user terminal device, which is communicatively connected to the data center, a usage request for the use of a service executed by one of the plurality of virtual servers for a finite period of time. The finite period of time occurs within a first time period. The information processing device is configured to calculate a cumulative usage fee for the usage request based on the finite period of time included in the usage request, a previous usage duration time of the service by the user terminal device, and a usage fee per unit time associated with the previous usage duration time. The information processing device is configured to output the predicted cumulative usage fee.

Abstract: A storage unit stores load information indicating the load of an information processing apparatus by applying each of a plurality of update programs to each virtual machine. An operation unit obtains the load information from the storage unit, and determines, for each virtual machine, an order of applying the plurality update programs to the virtual machine within a predetermined time period on the basis of the load information and an upper load limit allowable for the information processing apparatus.

Abstract: A storage unit stores load information indicating the load of an information processing apparatus by applying each of a plurality of update programs to each virtual machine. An operation unit obtains the load information from the storage unit, and determines, for each virtual machine, an order of applying the plurality update programs to the virtual machine within a predetermined time period on the basis of the load information and an upper load limit allowable for the information processing apparatus.