Distributed batch processing on an eventually consistent storage system is efficiently performed. A control node includes an execution control unit and a re-execution control unit. The execution control unit causes a processing node to execute predetermined processing that includes reading of data for a key stored in a distributed data store. The re-execution control unit determines, after causing the processing node to execute the predetermined processing, presence or absence of a possibility that inconsistency occurred on data for the key stored in the distributed data store at a time of execution of the predetermined processing, based on a representative value of the data. Then, the re-execution control unit causes, when it is determined that there is a possibility that the inconsistency occurred, the processing node to re-execute the predetermined processing at a time point when resolution of the inconsistency is verified.