When a failure occurs in data matching processing, a quick data backup processing is required. For such an object, the data processing apparatus includes a data distribution part which stores a file data group in a normal data holding area of the j-th matching node and performs a backup processing by dividing the file data included in the file data group in the backup data holding area in the matching nodes other than the j-th matching node. The backup processing is performed by distributing each of the file data in the file data group to the backup data holding area in turn from a least backup data holding area where a file data being currently stored is least among the matching nodes.