title: GCP Alerting - how to set uptime threshold?
body: <p>We are trying to setup GKE uptime alerts for our kubernetes cluster using the new (ie. non-legacy) GCP dashboard.  Similar alerts are working fine for CPU/Memory utlization, but something about uptime is strange.</p>
  <p>The policy shown below applies to our prod cluster and sets a rolling window of 10 minutes and applies count as the aggregator function.  The count is the number of uptime minutes.  On the right, I have turned off a service.  You can see that this causes a stepwise change that gradually steps down from 10 (fully up) to zero (fully down over course of ten minutes).  When the metric hits 0 (ie. below threshold value 1), we should get an alert.</p>
  <p><a href="https://i.stack.imgur.com/yfKnC.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/yfKnC.png" alt="enter image description here" /></a></p>
  <p><a href="https://i.stack.imgur.com/LgEOA.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/LgEOA.png" alt="enter image description here" /></a></p>
  <p>However, rather than going to 0, the value of the count shows as &quot;-&quot; in the UI.  I assume this means null or something?  As you can see in the step function, the steps go 10,9,8....3,2,1 and then disappear without ever becoming 0.  Why would the count not go to zero and instead go to &quot;-&quot; on the UI?  The metric description itself shows it as a <code>Double</code>, so would epect it to go to 0...</p>
  <p><a href="https://i.stack.imgur.com/9BiRo.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/9BiRo.png" alt="enter image description here" /></a></p>
  <p>Do we have the wrong metric, or should we just set the threshold to below 2 instead as a workaround? Or perhaps I should choose &quot;Metric Absence&quot; as the best way to track this?</p>