Patent attributes
A management device is connected with a plurality of relay devices, and the relay devices store data collected by a device. The management device registers, when a connection notification is received from one of the relay devices, relay device identification information, which identifies the relay device, of the relay device serving as the request destination when the data is acquired, sends a data acquisition request to the specified relay device, and sends, to one of the relay devices, relay device identification information of the target relay device targeted for deletion. The plurality of the relay devices associates, when the identification information targeted for the deletion is received, inquiry destination information specifying the target relay device with the data, and performs, when the data acquisition request is received, response control of the data on the basis of the determination of whether the inquiry destination information is associated with the data.
