An information processing system includes a processor configured to: perform standard synchronization that synchronizes information between the information processing system and a synchronization destination by communicating with the synchronization destination at predetermined time intervals; and if the information processing system becomes unable to communicate with the synchronization destination in a communication disabled state, transmit, to one of the other information processing systems performing the standard synchronization, an execution instruction that causes the one information processing system to perform proxy synchronization to operate as a proxy for synchronization of the information between the information processing system and the synchronization destination.