I recall in WebMap v15 EP05+ any change in the WebMap Publisher (WMPS) metadata will trigger WMPS cache refresh process. How does this detection mechanism work?
The detection mechanism checks the UpdateSequence column of the WPSettings table in the WebMap Publisher metadata. The WebMap Publisher set it to a negative value while updating, which prohibits capabilities generation (and actually makes the MapSvr refuse connections to the library), and then set it to a positive value of (previous value)+1 which signals that something has been updated. The WMPS has each capabilities document tagged with the UpdateSequence value that was present while generating the capabilities document and when the next request for the capabilities reaches it, it verifies whether the values still match. If they don’t, the cache for the specific WebPub application is flushed.