Issue #5539 - Proper StatisticsServlet output format via content negotiation

[joakime]

StatisticsServer can now present it's information in (text, html, json, and xml).

Selected via normal HTTP content negotiation.

Example output (expand to see details)

$ curl -H "Accept: text/xml" http://localhost:9090/stats

<statistics>
  <connections>
    <connection>
      <name>org.eclipse.jetty.server.ServerConnector@4A87761D</name>
      <protocols>
        <protocol>http/1.1</protocol>
      </protocols>
      <statsOn>false</statsOn>
    </connection>
  </connections>
  <memory>
    <heapMemoryUsage>359372240</heapMemoryUsage>
    <nonHeapMemoryUsage>22923928</nonHeapMemoryUsage>
  </memory>
  <requests>
    <asyncRequests>0</asyncRequests>
    <dispatched>8</dispatched>
    <dispatchedActive>1</dispatchedActive>
    <dispatchedActiveMax>1</dispatchedActiveMax>
    <dispatchedTimeMax>12</dispatchedTimeMax>
    <dispatchedTimeMean>3.857142857142857</dispatchedTimeMean>
    <dispatchedTimeStdDev>3.0613177990314346</dispatchedTimeStdDev>
    <dispatchedTimeTotal>27</dispatchedTimeTotal>
    <errors>0</errors>
    <requests>8</requests>
    <requestsActive>1</requestsActive>
    <requestsActiveMax>1</requestsActiveMax>
    <requestsExpired>0</requestsExpired>
    <requestsResumed>0</requestsResumed>
    <requestsSuspended>0</requestsSuspended>
    <requestsSuspendedMax>0</requestsSuspendedMax>
    <requestsTimeMax>12</requestsTimeMax>
    <requestsTimeMean>3.857142857142857</requestsTimeMean>
    <requestsTimeStdDev>3.0613177990314346</requestsTimeStdDev>
    <requestsTimeTotal>27</requestsTimeTotal>
    <statsOnMs>132823</statsOnMs>
  </requests>
  <responses>
    <responses1xx>0</responses1xx>
    <responses2xx>6</responses2xx>
    <responses3xx>0</responses3xx>
    <responses4xx>1</responses4xx>
    <responses5xx>0</responses5xx>
    <responsesBytesTotal>6996</responsesBytesTotal>
  </responses>
</statistics>

$ curl -H "Accept: application/json" http://localhost:9090/stats | json_pp

{
   "requests" : {
      "dispatchedActive" : 1,
      "requestsActiveMax" : 1,
      "requestsTimeStdDev" : 3.11094840844396,
      "statsOnMs" : 97118,
      "errors" : 0,
      "requestsActive" : 1,
      "requestsExpired" : 0,
      "dispatchedTimeTotal" : 26,
      "asyncRequests" : 0,
      "dispatchedTimeMax" : 12,
      "requestsSuspendedMax" : 0,
      "requestsTimeTotal" : 26,
      "requestsTimeMax" : 12,
      "requestsSuspended" : 0,
      "requestsTimeMean" : 4.33333333333333,
      "dispatchedTimeStdDev" : 3.11094840844396,
      "dispatchedTimeMean" : 4.33333333333333,
      "dispatched" : 7,
      "requests" : 7,
      "dispatchedActiveMax" : 1,
      "requestsResumed" : 0
   },
   "memory" : {
      "heapMemoryUsage" : 359372240,
      "nonHeapMemoryUsage" : 22911656
   },
   "responses" : {
      "responses3xx" : 0,
      "responses4xx" : 1,
      "responses2xx" : 5,
      "responses1xx" : 0,
      "responsesBytesTotal" : 6171,
      "responses5xx" : 0
   },
   "connections" : [
      {
         "protocols" : [
            "http/1.1"
         ],
         "statsOn" : false,
         "name" : "org.eclipse.jetty.server.ServerConnector@4A87761D"
      }
   ]
}

$ curl -H "Accept: text/plain" http://localhost:9090/stats

statistics: 
  connections: 
    connection: 
      name: org.eclipse.jetty.server.ServerConnector@4A87761D
      protocols: 
        protocol: http/1.1
      statsOn: false
  memory: 
    heapMemoryUsage: 369941880
    nonHeapMemoryUsage: 22951424
  requests: 
    asyncRequests: 0
    dispatched: 9
    dispatchedActive: 1
    dispatchedActiveMax: 1
    dispatchedTimeMax: 12
    dispatchedTimeMean: 3.625
    dispatchedTimeStdDev: 2.8980288867731163
    dispatchedTimeTotal: 29
    errors: 0
    requests: 9
    requestsActive: 1
    requestsActiveMax: 1
    requestsExpired: 0
    requestsResumed: 0
    requestsSuspended: 0
    requestsSuspendedMax: 0
    requestsTimeMax: 12
    requestsTimeMean: 3.625
    requestsTimeStdDev: 2.8980288867731163
    requestsTimeTotal: 29
    statsOnMs: 147503
  responses: 
    responses1xx: 0
    responses2xx: 7
    responses3xx: 0
    responses4xx: 1
    responses5xx: 0
    responsesBytesTotal: 8618

$ curl -H "Accept: text/html" http://localhost:9090/stats

<html><head><title>StatisticsServlet</title></head><body>
<ul>
<li><em>statistics</em>: 
  <ul>
    <li><em>connections</em>: 
      <ul>
        <li><em>connection</em>: 
          <ul>
            <li><em>name</em>: org.eclipse.jetty.server.ServerConnector@4A87761D</li>
            <li><em>protocols</em>: 
              <ul>
                <li><em>protocol</em>: http/1.1</li>
              </ul>
              </li>
            <li><em>statsOn</em>: false</li>
          </ul>
          </li>
      </ul>
      </li>
    <li><em>memory</em>: 
      <ul>
        <li><em>heapMemoryUsage</em>: 369941880</li>
        <li><em>nonHeapMemoryUsage</em>: 22965800</li>
      </ul>
      </li>
    <li><em>requests</em>: 
      <ul>
        <li><em>asyncRequests</em>: 0</li>
        <li><em>dispatched</em>: 10</li>
        <li><em>dispatchedActive</em>: 1</li>
        <li><em>dispatchedActiveMax</em>: 1</li>
        <li><em>dispatchedTimeMax</em>: 12</li>
        <li><em>dispatchedTimeMean</em>: 3.4444444444444446</li>
        <li><em>dispatchedTimeStdDev</em>: 2.7556759606310752</li>
        <li><em>dispatchedTimeTotal</em>: 31</li>
        <li><em>errors</em>: 0</li>
        <li><em>requests</em>: 10</li>
        <li><em>requestsActive</em>: 1</li>
        <li><em>requestsActiveMax</em>: 1</li>
        <li><em>requestsExpired</em>: 0</li>
        <li><em>requestsResumed</em>: 0</li>
        <li><em>requestsSuspended</em>: 0</li>
        <li><em>requestsSuspendedMax</em>: 0</li>
        <li><em>requestsTimeMax</em>: 12</li>
        <li><em>requestsTimeMean</em>: 3.4444444444444446</li>
        <li><em>requestsTimeStdDev</em>: 2.7556759606310752</li>
        <li><em>requestsTimeTotal</em>: 31</li>
        <li><em>statsOnMs</em>: 163911</li>
      </ul>
      </li>
    <li><em>responses</em>: 
      <ul>
        <li><em>responses1xx</em>: 0</li>
        <li><em>responses2xx</em>: 8</li>
        <li><em>responses3xx</em>: 0</li>
        <li><em>responses4xx</em>: 1</li>
        <li><em>responses5xx</em>: 0</li>
        <li><em>responsesBytesTotal</em>: 9562</li>
      </ul>
      </li>
  </ul>
  </li>
</ul>

</body></html>

Signed-off-by: Joakim Erdfelt joakim.erdfelt@gmail.com

[joakime]

I need to add test cases to test-distribution for this.