After we register and start listening on a metric, the metric will stay there forever reporting. However, it is sometimes annoying to have too many or unnecessary metric reporting. As a result, there is a need to enable metric disabling mechanism in the MCO. It is expected to get wired up with the CRD work in the future so that the user will be granted the chance to choose which metric to turn on and turn off at any time. 

Update:

Attempted Unregister(), which enables metric shutdown but does not allow re-register after unregister. Need to find a better way for metric shutting down.