An information processing system includes a plurality of information processing apparatuses, and a control apparatus that collects data included in each of the plurality of information processing apparatuses. Each of the plurality of information processing apparatuses or the control apparatus determines a first number of first information processing apparatuses that compress the data or a second number of second information processing apparatuses that do not compress the data, the first information processing apparatuses and the second information processing apparatuses being included in the plurality of information processing apparatuses, based on a parameter involved in decompression processing by the control apparatus. The first number of first information processing apparatuses compress the data and transmit compressed data to the control apparatus, and the second number of second information processing apparatuses transmit non-compressed data to the control apparatus without compressing the data.