title: AWS CloudWatch alarm: Trigger when RDS instance is available but not used
body: <p>I would like to create a CloudWatch alarm that sends an email when I forgot to delete my RDS instance after use. So I only want an alarm that triggers when the RDS instance is available. My initial approach is the following:</p>
  
  <p>Create an alarm based on "CPUUtilization" and have it trigger when the utilization has on average been between 0 and 1 percent for about 1 or 2 hours.</p>
  
  <p>However, until now I can only state 1 constraint. What I mean is that I can have the alarm trigger when the utilization is below 1 percent for about 1 or 2 hours. But this means that it will also trigger when the instance has been deleted.</p>
  
  <p>Can anyone help me figuring out how to tackle this problem?</p>