title: get time that passed since the last increase of Prometheus counter
body: <p>Consider a Prometheus metric <code>foo_total</code> that counts the total amount of occurences of an event <code>foo</code>, i.e. the metric will only increase as long as the providing service isn't restarted.</p>
  
  <p>Is there any way to get the timespan (e.g. amount of seconds) since the last increase of that metric? I know that due to the scrape period, the value for sure isn't that accurate, but an accurancy of a couple of minutes should be sufficent for me.</p>
  
  <p><strong>Background</strong>: I want to use that kind of query in Grafana to have an overview if some services are used regularly and if some jobs are done within a defined grace period. I don't have any influence on the metric itself. </p>