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; analyzing, by said computer processor executing said aggregator module, said periodic monitoring data; determining based on results of said analyzing, by said computer processor executing said aggregator module, unique updates applied to said plurality of virtual machine instances; first identifying, by said computer processor executing an instance update manager of said mapping application, first high level semantic updates 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; second identifying, by said computer processor executing an image update manager of said mapping application, high level semantic updates to said golden master image; 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.