title: New Relic Servers API Getting data using available metrics
body: <p>I'm running a New Relic server agent on a couple Linux boxes (in R&amp;D stage right now) for gathering performance data, CPU utilization, Memory, etc. I've the the NR API to get back available metrics and the names passable to them. However, I'm not entirely sure how to get that data back correctly (not convinced it's even possible at this point). The one I'm most concerned about this point is:</p>
  
  <p><code>System/Disk/^dev^xvda1/Utilization/percent</code>. </p>
  
  <p>With available names:</p>
  
  <p><code>[u'average_response_time', u'calls_per_minute', u'call_count', u'min_response_time', u'max_response_time', u'average_exclusive_time', u'average_value', u'total_call_time_per_minute', u'requests_per_minute', u'standard_deviation']</code></p>
  
  <p>According to the NR API doc, the proper end point for this is <code>https://api.newrelic.com/v2/servers/${APP_ID}/metrics/data.xml</code>. Where I <strong>assume</strong> <code>${APP_ID}</code> is the Server ID. </p>
  
  <p>So, I'm able to send the request, however, the data I'm getting back is not at all what I'm looking for.
  Response:</p>
  
  <pre><code>          &lt;average_response_time&gt;0&lt;/average_response_time&gt;
            &lt;calls_per_minute&gt;1.4&lt;/calls_per_minute&gt;
            &lt;call_count&gt;1&lt;/call_count&gt;
            &lt;min_response_time&gt;0&lt;/min_response_time&gt;
            &lt;max_response_time&gt;0&lt;/max_response_time&gt;
            &lt;average_exclusive_time&gt;0&lt;/average_exclusive_time&gt;
            &lt;average_value&gt;0&lt;/average_value&gt;
            &lt;total_call_time_per_minute&gt;0&lt;/total_call_time_per_minute&gt;
            &lt;requests_per_minute&gt;1.4&lt;/requests_per_minute&gt;
            &lt;standard_deviation&gt;0&lt;/standard_deviation&gt;
  </code></pre>
  
  <p>Which would be what is expected. I think the data in <em>these</em> metrics is accurate, but I think they're to be taken at face value. However, the reason I even say they're to be taken for face value is based upon this statement in the NR API Docs:</p>
  
  <p><strong>Metric values include:
  Total disk space used, indicated by average_response_time
  Capacity of the disk, indicated by average_exclusive_time</strong>. </p>
  
  <p>Which would lead one to believe that the data we want is is listed within one of the available name parameters for the the request. So, essentially my question is, <strong>is there a more specific way I need to hit the NR API to actually get the disk utilization as a percentage? Or is that not possible, even though I'm given to believe otherwise based upon the aforementioned information?</strong>. I'm hoping maybe there is information I'm missing here... Thanks!</p>