DATA SET MULTIPLICITY CHANGE DEVICE, SERVER, DATA SET MULTIPLICITY CHANGE METHOD AND COMPUTER REDABLE MEDIUM

摘要

A data set multiplicity change device of the invention, after a job is started, the number of data sets (multiplicity M) can be changed so that the access efficiency for accessing multiplicity management target data sets becomes as high as possible. The data set multiplicity change device includes priority degree calculation unit which calculates priority degree information representing an order of a plurality of nodes into which data sets are to be stored, on the basis of data set usage related information including information related to usage of the data sets referred to in a parallel processing executed by the plurality of nodes; and multiplicity management unit which performs multiplicity change processing to change a multiplicity of the data sets by changing the number of at least one or more data sets held in the plurality of nodes in a distributed manner on the basis of the priority degree information and data set arrangement information indicating a particular node holding the data sets in a storage area thereof.