(A) and (B), described hereinafter, are carried out for objects which differ between an reflection source namespace and a reflection destination namespace, with respect to either: a center node in a migration, which applies an update of a first local namespace which a first edge node (any edge node) provides to a center namespace; or a second edge node (any edge node other than the first edge node) in a synchronization, which applies an update of the center namespace to a second local namespace which the second edge node provides. Specifically, either the center node or the second edge node: (A) determines whether the situation with respect to the differing objects corresponds to a conflict case among defined conflict cases; and (B) if the result of the determination in (A) is affirmative, executes a process according to a confliction resolution policy which is associated with the corresponding conflict case.