title: Query label_values not found in Prometheus
body: <p>In the Grafana documentation, I found that I should be able to query my Prometheus server for all instances delivering monitoring data using the <code>label_values</code> query.</p>
  
  <p>The query I'm using in Grafana is: </p>
  
  <pre><code>label_values(up, instance)
  </code></pre>
  
  <p>Unfortunately, Prometheus tells me that it is not aware of label_values:</p>
  
  <pre class="lang-sh prettyprint-override"><code>Error executing query: parse error at char 13: unknown function with name "label_values"
  </code></pre>
  
  <p>I am using Prometheus 2.0.0 and Grafana 5.</p>
  
  <p>What am I doing wrong?</p>