An apparatus includes a memory to store objects of a plurality of classes, and a storage device to store plural pieces of dump data acquired at different times from the memory. The apparatus generates object-count information indicating a number of objects belonging to each of a plurality of classes, based on the plural pieces of dump data acquired at different times from a memory storing objects of the plurality of classes. The apparatus determines, for each class, at least a portion of dump data that includes a locally minimum number of objects in time variation of the number of objects of the each class, as first dump data that is candidate for storage, based on the generated object-count information. When reducing a total amount of dump data, the apparatus excludes the first dump data determined for each class from second dump data that is to be deleted.