Clustering tree structured data

Question

Suppose we are given data in a semi-structured format as a tree. As an example, the tree can be formed as a valid XML document or as a valid JSON document. You could imagine it

Answer 1

Here you may find a paper that seems closely related to your problem.

From the abstract:

This thesis presents Ixor, a system which collects, stores, and analyzes stack traces in distributed Java systems. When combined with third-party clustering software and adaptive cluster filtering, unusual executions can be identified.