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; a data distribution part configured to store a 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 matching node of the plurality of matching nodes when the file data group is inputted, and configured 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 backup data; a data matching switching part configured to perform matching of the file data group stored in the normal data holding area of each of the plurality of matching data and target data being a target of matching when the target data is inputted, and configured to switch into backup matching processing by which matching of the plurality of file data stored in the backup data holding area of each of the plurality of matching nodes other than the j-th matching node and the target data is performed when a failure occurs at the j-th matching node; and a table in which a place where each of the plurality of file data is stored among the plurality of matching nodes by the backup processing is indicated, wherein j is an integer, wherein the backup matching processing is performed by searching the backup data holding area where the backup data of the j-th matching node is stored among the plurality of matching nodes by referring to the table, 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, wherein the backup processing is performed at a stage of storing the file data group in the plurality of matching nodes and the backup matching processing is performed after the backup processing is performed.