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<p>To observe Heron's runtime metrics, you can integrate Heron and the Heron UI with
<a href="http://graphite.readthedocs.io/en/latest/overview.html">Graphite</a> and
<a href="http://grafana.org/">Grafana</a>.</p>
<p>To accomplish this, you need to do the following:</p>
<ul>
<li>Export topology metrics from Heron</li>
<li>Gather Aurora and Linux metrics with Diamond</li>
<li>Set up a scripted dashboard with Grafana</li>
<li>Configure the Heron UI to link to Grafana</li>
</ul>
<h3><a class="anchor" aria-hidden="true" id="exporting-topology-metrics-from-heron"></a><a href="#exporting-topology-metrics-from-heron" aria-hidden="true" class="hash-link"><svg class="hash-link-icon" aria-hidden="true" height="16" version="1.1" viewBox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"></path></svg></a>Exporting Topology Metrics From Heron</h3>
<p>Heron supports custom metric exporters from the Metrics Manager. You can either build your own Graphite metrics sink or use the <a href="extending-heron-metric-sink">provided Graphite sink</a>.</p>
<h3><a class="anchor" aria-hidden="true" id="gathering-metrics-from-aurora"></a><a href="#gathering-metrics-from-aurora" aria-hidden="true" class="hash-link"><svg class="hash-link-icon" aria-hidden="true" height="16" version="1.1" viewBox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"></path></svg></a>Gathering Metrics From Aurora</h3>
<p>In addition to the topology-specific data available from Heron, much more data is available directly
from Aurora and the Linux kernel. These can help identify many operational problems, such as
CPU throttling or crashes.</p>
<p>A common way to collect data from these sources is via a system metrics collection daemon such as
<a href="https://collectd.org/">collectd</a> or <a href="https://github.com/python-diamond/Diamond">Diamond</a></p>
<p>Diamond has the following relevant collectors available:</p>
<ul>
<li><a href="https://github.com/python-diamond/Diamond/tree/master/src/collectors/aurora">Aurora</a></li>
</ul>
<h3><a class="anchor" aria-hidden="true" id="creating-a-scripted-grafana-dashboard"></a><a href="#creating-a-scripted-grafana-dashboard" aria-hidden="true" class="hash-link"><svg class="hash-link-icon" aria-hidden="true" height="16" version="1.1" viewBox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"></path></svg></a>Creating A Scripted Grafana Dashboard</h3>
<p>A convienent way to view topology-specific metrics in Graphite is to create a
<a href="http://docs.grafana.org/reference/scripting/">scripted dashboard in Grafana</a>. The scripted
dashboard should accept information such as the topology name as query arguments, which will allow
the Heron UI to deep link to a specific topology's dashboard.</p>
<p>Suggested targets for the scripted dashboard include:</p>
<p><strong>Component Backpressure</strong>:</p>
<pre><code class="hljs css language-python">'aliasByNode(sortByMaxima(highestAverage(heron.' + topology_name + '.stmgr.stmgr-*.
time_spent_back_pressure_by_compid.*, 5)), 5)'
</code></pre>
<p><strong>Fail Count by Component</strong>:</p>
<pre><code class="hljs css language-python"><span class="hljs-string">'sumSeriesWithWildcards(aliasByNode(heron.'</span> + topology_name + <span class="hljs-string">'.*.*.fail-count.default,2),3)'</span>`
</code></pre>
<p><strong>CPU Throttling periods</strong>:</p>
<pre><code class="hljs css language-python">aliasByNode(nonNegativeDerivative(mesos.tasks.prod.*.<span class="hljs-string">' + topology_name + '</span>.*.cpu.
nr_throttled), <span class="hljs-number">4</span>,<span class="hljs-number">5</span>)
</code></pre>
<p><strong>JVM Deaths</strong>:</p>
<pre><code class="hljs css language-python">'aliasByNode(drawAsInfinite(maximumAbove(removeAboveValue(heron.' + topology_name + '.*.*.jvm.
uptime-secs, 60),1)),2,3)'
</code></pre>
<p><strong>Top 5 worst GC components</strong>:</p>
<pre><code class="hljs css language-python">'aliasByNode(highestMax(nonNegativeDerivative(heron.' + topology_name + '.*.*.jvm.gc-time-ms.
PS-*),5), 2,3,6)'
</code></pre>
<h3><a class="anchor" aria-hidden="true" id="configuring-the-heron-ui-link-to-grafana"></a><a href="#configuring-the-heron-ui-link-to-grafana" aria-hidden="true" class="hash-link"><svg class="hash-link-icon" aria-hidden="true" height="16" version="1.1" viewBox="0 0 16 16" width="16"><path fill-rule="evenodd" d="M4 9h1v1H4c-1.5 0-3-1.69-3-3.5S2.55 3 4 3h4c1.45 0 3 1.69 3 3.5 0 1.41-.91 2.72-2 3.25V8.59c.58-.45 1-1.27 1-2.09C10 5.22 8.98 4 8 4H4c-.98 0-2 1.22-2 2.5S3 9 4 9zm9-3h-1v1h1c1 0 2 1.22 2 2.5S13.98 12 13 12H9c-.98 0-2-1.22-2-2.5 0-.83.42-1.64 1-2.09V6.25c-1.09.53-2 1.84-2 3.25C6 11.31 7.55 13 9 13h4c1.45 0 3-1.69 3-3.5S14.5 6 13 6z"></path></svg></a>Configuring The Heron UI Link To Grafana</h3>
<p>Finally, you can configure the Heron UI to deep link to scripted dashboards by specifying an
[observability URL format]
(<a href="https://github.com/apache/incubator-heron/blob/master/heron/tools/config/src/yaml/tracker/heron_tracker.yaml">https://github.com/apache/incubator-heron/blob/master/heron/tools/config/src/yaml/tracker/heron_tracker.yaml</a>)
(<code>viz.url.format</code>) in the Heron Tracker's configuration. This will add topology-specific buttons to
the Heron UI enabling you to drill-down into your Grafana dashboards.</p>
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