TREE EXTRACTION DEVICE, TREE EXTRACTION SYSTEM, TREE EXTRACTION METHOD AND TREE EXTRACTION PROGRAM

PROBLEM TO BE SOLVED: To extract a tree structure from a large amount of log data with high speed.SOLUTION: A server device 20-1 comprises a tree edge extraction unit 22, a subtree configuration unit 23, a tree extraction preparation unit 24, and a tree extraction unit 25. The tree edge extraction unit 22 extracts an edge of a tree formed in each process from log data which includes a plurality of processes having mutual dependence. The subtree configuration unit 23 generates data of a categorization target using a first value common in each extracted edge and a second value other than the first value included in the edge. The tree extraction preparation unit 24 categorizes the tree into roots and branches by categorizing the generated data into data corresponding to the roots and data corresponding to the branches derived from the roots. The tree extraction unit 25 extracts the tree including the roots and the branches derived from the roots, from the log data on the basis of the categorized data.