1. A data processing apparatus comprising: a plurality of matching nodes, each of the plurality of matching nodes has a normal data holding area and a backup data holding area; and a data distribution part configured to store file data group, which includes a plurality of file data being registered for matching in advance, in the normal data holding area of a j-th (j is an integer) matching node of the plurality of data nodes when the file data group is inputted, to perform a backup processing by dividing the plurality of file data included in the file data group for distributing the plurality of file data to the backup data holding area of each of the plurality of matching nodes other than the j-th matching node as a backup data, wherein the backup processing is performed by distributing each of the plurality of file data included 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 plurality of matching nodes.