A disclosed information processing system includes plural information processing apparatuses connected with a network. One of the plural information processing apparatuses includes: a first allocation unit to identify, for each subnetwork of plural subnetworks included in the network, one information processing apparatus from among information processing apparatuses included in the subnetwork, and assign to the identified one information processing apparatus, a first Reduce processing that is a processing to summarize results of a Map processing executed for data held in the information processing apparatuses included in the subnetwork; and a second allocation unit to allocate to any one of the plural information processing apparatuses, a second Reduce processing that is a processing to summarize results of the first Reduce processing executed for each subnetwork of the plural subnetworks.