1. A method comprising: receiving from a plurality of change agents on a plurality of virtual machine instances, by a computer processor executing an aggregator module of a mapping application, periodic monitoring data indicating changes for each virtual machine instance of said plurality of virtual machine instances; determining based on results of analyzing said periodic monitoring data, by said computer processor executing said aggregator module, unique updates applied to said plurality of virtual machine instances; tracking, by said computer processor executing a change agent of said mapping application, updates associated with a golden master image used to generate said plurality of virtual machine instances; identifying, by said computer processor executing an image update manager of said mapping application, high level semantic updates to said golden master image, wherein said identifying comprises: performing a breadth-first search on a version graph to identify a cut on the version graph such that each edge in said cut comprises all elements of said high level semantic updates; splitting a node that immediately follows said cut into a node V1 and a node V2, wherein said node V1 captures changes of said high level semantic updates, and wherein said node V2 captures changes not in said high level semantic updates; promoting said node V1 to a root; and maintaining in response to results of said first identifying, said tracking and said second identifying, by said computer processor executing a version manager of said mapping application, a version tree configured to track drift of each said virtual machine instance with respect to said golden master image.