title: Grafana expression for prometheus histogram
body: <p>Can anyone help me with visualising a prometheus histogram as both a chart and apdex please?</p>
  
  <p>Ignoring any secondary labelling (for now) I'd just like to be able to visualise them as a histogram on Grafana (stacked bar chart is fine) and it would be really useful to also show the apdex in grafana.</p>
  
  <p>Examples of the buckets from the prometheus web console</p>
  
  <pre><code>someoperation_duration_seconds_bucket{
      labelOne="some_consistent_label",
      exported_instance="foo",
      exported_job="my_job",
      instance="10.0.0.0:9091",
      job="kubernetes-service-endpoints",
      kubernetes_name="prometheus-push-gateway",
      kubernetes_namespace="monitoring",
      le="+Inf",
      labelTwo="some_label_that_changes1"
  }
  
  someoperation_duration_seconds_bucket{
      labelOne="some_consistent_label",
      exported_instance="foo",
      exported_job="my_job",
      instance="10.0.0.0:9091",
      job="kubernetes-service-endpoints",
      kubernetes_name="prometheus-push-gateway",
      kubernetes_namespace="monitoring",
      le="120",
      labelTwo="some_label_that_changes1"
  } etc etc
  </code></pre>
  
  <p>I've viewed this post <a href="https://stackoverflow.com/questions/39135026/how-can-i-visualize-a-histogram-with-promdash-or-grafana/42300496#comment85347739_42300496">how can I visualize a histogram with promdash or grafana</a> and got the chart showing as a stacked bar with the series being the 'le' (bucket) values however the value for the Y axis for each bucket has exactly the same value.</p>
  
  <p>Because of the nature of the operation the metrics are collected via a PushGateway. Not sure if that has an impact.</p>
  
  <p>Many thanks all</p>