---
layout: docpage

title: "Documentation"

is_homepage: false
is_sphinx_doc: true

doc-parent: "Operating Cassandra"

doc-title: "Monitoring"
doc-header-links: '
  <link rel="top" title="Apache Cassandra Documentation v4.0-beta4" href="../index.html"/>
      <link rel="up" title="Operating Cassandra" href="index.html"/>
      <link rel="next" title="Security" href="security.html"/>
      <link rel="prev" title="Bulk Loading" href="bulk_loading.html"/>
'
doc-search-path: "../search.html"

extra-footer: '
<script type="text/javascript">
    var DOCUMENTATION_OPTIONS = {
      URL_ROOT:    "",
      VERSION:     "",
      COLLAPSE_INDEX: false,
      FILE_SUFFIX: ".html",
      HAS_SOURCE:  false,
      SOURCELINK_SUFFIX: ".txt"
    };
</script>
'

---
<div class="container-fluid">
  <div class="row">
    <div class="col-md-3">
      <div class="doc-navigation">
        <div class="doc-menu" role="navigation">
          <div class="navbar-header">
            <button type="button" class="pull-left navbar-toggle" data-toggle="collapse" data-target=".sidebar-navbar-collapse">
              <span class="sr-only">Toggle navigation</span>
              <span class="icon-bar"></span>
              <span class="icon-bar"></span>
              <span class="icon-bar"></span>
            </button>
          </div>
          <div class="navbar-collapse collapse sidebar-navbar-collapse">
            <form id="doc-search-form" class="navbar-form" action="../search.html" method="get" role="search">
              <div class="form-group">
                <input type="text" size="30" class="form-control input-sm" name="q" placeholder="Search docs">
                <input type="hidden" name="check_keywords" value="yes" />
                <input type="hidden" name="area" value="default" />
              </div>
            </form>
            
            
            <ul class="current">
<li class="toctree-l1"><a class="reference internal" href="../getting_started/index.html">Getting Started</a></li>
<li class="toctree-l1"><a class="reference internal" href="../new/index.html">New Features in Apache Cassandra 4.0</a></li>
<li class="toctree-l1"><a class="reference internal" href="../architecture/index.html">Architecture</a></li>
<li class="toctree-l1"><a class="reference internal" href="../cql/index.html">The Cassandra Query Language (CQL)</a></li>
<li class="toctree-l1"><a class="reference internal" href="../data_modeling/index.html">Data Modeling</a></li>
<li class="toctree-l1"><a class="reference internal" href="../configuration/index.html">Configuring Cassandra</a></li>
<li class="toctree-l1 current"><a class="reference internal" href="index.html">Operating Cassandra</a><ul class="current">
<li class="toctree-l2"><a class="reference internal" href="snitch.html">Snitch</a></li>
<li class="toctree-l2"><a class="reference internal" href="topo_changes.html">Adding, replacing, moving and removing nodes</a></li>
<li class="toctree-l2"><a class="reference internal" href="repair.html">Repair</a></li>
<li class="toctree-l2"><a class="reference internal" href="read_repair.html">Read repair</a></li>
<li class="toctree-l2"><a class="reference internal" href="hints.html">Hints</a></li>
<li class="toctree-l2"><a class="reference internal" href="compaction/index.html">Compaction</a></li>
<li class="toctree-l2"><a class="reference internal" href="bloom_filters.html">Bloom Filters</a></li>
<li class="toctree-l2"><a class="reference internal" href="compression.html">Compression</a></li>
<li class="toctree-l2"><a class="reference internal" href="cdc.html">Change Data Capture</a></li>
<li class="toctree-l2"><a class="reference internal" href="backups.html">Backups</a></li>
<li class="toctree-l2"><a class="reference internal" href="bulk_loading.html">Bulk Loading</a></li>
<li class="toctree-l2 current"><a class="current reference internal" href="#">Monitoring</a><ul>
<li class="toctree-l3"><a class="reference internal" href="#metric-types">Metric Types</a></li>
<li class="toctree-l3"><a class="reference internal" href="#table-metrics">Table Metrics</a></li>
<li class="toctree-l3"><a class="reference internal" href="#keyspace-metrics">Keyspace Metrics</a></li>
<li class="toctree-l3"><a class="reference internal" href="#threadpool-metrics">ThreadPool Metrics</a></li>
<li class="toctree-l3"><a class="reference internal" href="#client-request-metrics">Client Request Metrics</a></li>
<li class="toctree-l3"><a class="reference internal" href="#cache-metrics">Cache Metrics</a></li>
<li class="toctree-l3"><a class="reference internal" href="#cql-metrics">CQL Metrics</a></li>
<li class="toctree-l3"><a class="reference internal" href="#droppedmessage-metrics">DroppedMessage Metrics</a></li>
<li class="toctree-l3"><a class="reference internal" href="#streaming-metrics">Streaming Metrics</a></li>
<li class="toctree-l3"><a class="reference internal" href="#compaction-metrics">Compaction Metrics</a></li>
<li class="toctree-l3"><a class="reference internal" href="#commitlog-metrics">CommitLog Metrics</a></li>
<li class="toctree-l3"><a class="reference internal" href="#storage-metrics">Storage Metrics</a></li>
<li class="toctree-l3"><a class="reference internal" href="#hintsservice-metrics">HintsService Metrics</a></li>
<li class="toctree-l3"><a class="reference internal" href="#sstable-index-metrics">SSTable Index Metrics</a></li>
<li class="toctree-l3"><a class="reference internal" href="#bufferpool-metrics">BufferPool Metrics</a></li>
<li class="toctree-l3"><a class="reference internal" href="#client-metrics">Client Metrics</a></li>
<li class="toctree-l3"><a class="reference internal" href="#batch-metrics">Batch Metrics</a></li>
<li class="toctree-l3"><a class="reference internal" href="#jvm-metrics">JVM Metrics</a></li>
<li class="toctree-l3"><a class="reference internal" href="#jmx">JMX</a></li>
<li class="toctree-l3"><a class="reference internal" href="#metric-reporters">Metric Reporters</a></li>
</ul>
</li>
<li class="toctree-l2"><a class="reference internal" href="security.html">Security</a></li>
<li class="toctree-l2"><a class="reference internal" href="hardware.html">Hardware Choices</a></li>
</ul>
</li>
<li class="toctree-l1"><a class="reference internal" href="../tools/index.html">Cassandra Tools</a></li>
<li class="toctree-l1"><a class="reference internal" href="../troubleshooting/index.html">Troubleshooting</a></li>
<li class="toctree-l1"><a class="reference internal" href="../development/index.html">Contributing to Cassandra</a></li>
<li class="toctree-l1"><a class="reference internal" href="../faq/index.html">Frequently Asked Questions</a></li>
<li class="toctree-l1"><a class="reference internal" href="../plugins/index.html">Third-Party Plugins</a></li>
<li class="toctree-l1"><a class="reference internal" href="../bugs.html">Reporting Bugs</a></li>
<li class="toctree-l1"><a class="reference internal" href="../contactus.html">Contact us</a></li>
</ul>

            
          </div><!--/.nav-collapse -->
        </div>
      </div>
    </div>
    <div class="col-md-8">
      <div class="content doc-content">
        <div class="content-container">
          
  <div class="section" id="monitoring">
<span id="monitoring-metrics"></span><h1>Monitoring<a class="headerlink" href="#monitoring" title="Permalink to this headline">¶</a></h1>
<p>Metrics in Cassandra are managed using the <a class="reference external" href="http://metrics.dropwizard.io">Dropwizard Metrics</a> library. These metrics
can be queried via JMX or pushed to external monitoring systems using a number of <a class="reference external" href="http://metrics.dropwizard.io/3.1.0/getting-started/#other-reporting">built in</a> and <a class="reference external" href="http://metrics.dropwizard.io/3.1.0/manual/third-party/">third party</a> reporter plugins.</p>
<p>Metrics are collected for a single node. It’s up to the operator to use an external monitoring system to aggregate them.</p>
<div class="section" id="metric-types">
<h2>Metric Types<a class="headerlink" href="#metric-types" title="Permalink to this headline">¶</a></h2>
<p>All metrics reported by cassandra fit into one of the following types.</p>
<dl class="docutils">
<dt><code class="docutils literal notranslate"><span class="pre">Gauge</span></code></dt>
<dd>An instantaneous measurement of a value.</dd>
<dt><code class="docutils literal notranslate"><span class="pre">Counter</span></code></dt>
<dd>A gauge for an <code class="docutils literal notranslate"><span class="pre">AtomicLong</span></code> instance. Typically this is consumed by monitoring the change since the last call to
see if there is a large increase compared to the norm.</dd>
<dt><code class="docutils literal notranslate"><span class="pre">Histogram</span></code></dt>
<dd><p class="first">Measures the statistical distribution of values in a stream of data.</p>
<p class="last">In addition to minimum, maximum, mean, etc., it also measures median, 75th, 90th, 95th, 98th, 99th, and 99.9th
percentiles.</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">Timer</span></code></dt>
<dd>Measures both the rate that a particular piece of code is called and the histogram of its duration.</dd>
<dt><code class="docutils literal notranslate"><span class="pre">Latency</span></code></dt>
<dd>Special type that tracks latency (in microseconds) with a <code class="docutils literal notranslate"><span class="pre">Timer</span></code> plus a <code class="docutils literal notranslate"><span class="pre">Counter</span></code> that tracks the total latency
accrued since starting. The former is useful if you track the change in total latency since the last check. Each
metric name of this type will have ‘Latency’ and ‘TotalLatency’ appended to it.</dd>
<dt><code class="docutils literal notranslate"><span class="pre">Meter</span></code></dt>
<dd>A meter metric which measures mean throughput and one-, five-, and fifteen-minute exponentially-weighted moving
average throughputs.</dd>
</dl>
</div>
<div class="section" id="table-metrics">
<span id="id1"></span><h2>Table Metrics<a class="headerlink" href="#table-metrics" title="Permalink to this headline">¶</a></h2>
<p>Each table in Cassandra has metrics responsible for tracking its state and performance.</p>
<p>The metric names are all appended with the specific <code class="docutils literal notranslate"><span class="pre">Keyspace</span></code> and <code class="docutils literal notranslate"><span class="pre">Table</span></code> name.</p>
<p>Reported name format:</p>
<dl class="docutils">
<dt><strong>Metric Name</strong></dt>
<dd><code class="docutils literal notranslate"><span class="pre">org.apache.cassandra.metrics.Table.&lt;MetricName&gt;.&lt;Keyspace&gt;.&lt;Table&gt;</span></code></dd>
<dt><strong>JMX MBean</strong></dt>
<dd><code class="docutils literal notranslate"><span class="pre">org.apache.cassandra.metrics:type=Table</span> <span class="pre">keyspace=&lt;Keyspace&gt;</span> <span class="pre">scope=&lt;Table&gt;</span> <span class="pre">name=&lt;MetricName&gt;</span></code></dd>
</dl>
<div class="admonition note">
<p class="first admonition-title">Note</p>
<p class="last">There is a special table called ‘<code class="docutils literal notranslate"><span class="pre">all</span></code>’ without a keyspace. This represents the aggregation of metrics across
<strong>all</strong> tables and keyspaces on the node.</p>
</div>
</div>
<div class="section" id="keyspace-metrics">
<h2>Keyspace Metrics<a class="headerlink" href="#keyspace-metrics" title="Permalink to this headline">¶</a></h2>
<p>Each keyspace in Cassandra has metrics responsible for tracking its state and performance.</p>
<p>Most of these metrics are the same as the <code class="docutils literal notranslate"><span class="pre">Table</span> <span class="pre">Metrics</span></code> above, only they are aggregated at the Keyspace level. The keyspace specific metrics are specified in the table below.</p>
<p>Reported name format:</p>
<dl class="docutils">
<dt><strong>Metric Name</strong></dt>
<dd><code class="docutils literal notranslate"><span class="pre">org.apache.cassandra.metrics.keyspace.&lt;MetricName&gt;.&lt;Keyspace&gt;</span></code></dd>
<dt><strong>JMX MBean</strong></dt>
<dd><code class="docutils literal notranslate"><span class="pre">org.apache.cassandra.metrics:type=Keyspace</span> <span class="pre">scope=&lt;Keyspace&gt;</span> <span class="pre">name=&lt;MetricName&gt;</span></code></dd>
</dl>
<table border="1" class="docutils">
<colgroup>
<col width="20%" />
<col width="7%" />
<col width="73%" />
</colgroup>
<thead valign="bottom">
<tr class="row-odd"><th class="head">Name</th>
<th class="head">Type</th>
<th class="head">Description</th>
</tr>
</thead>
<tbody valign="top">
<tr class="row-even"><td>WriteFailedIdeaCL</td>
<td>Counter</td>
<td>Number of writes that failed to achieve the configured ideal consistency level or 0 if none is configured</td>
</tr>
<tr class="row-odd"><td>IdealCLWriteLatency</td>
<td>Latency</td>
<td>Coordinator latency of writes at the configured ideal consistency level. No values are recorded if ideal consistency level is not configured</td>
</tr>
<tr class="row-even"><td>RepairTime</td>
<td>Timer</td>
<td>Total time spent as repair coordinator.</td>
</tr>
<tr class="row-odd"><td>RepairPrepareTime</td>
<td>Timer</td>
<td>Total time spent preparing for repair.</td>
</tr>
</tbody>
</table>
</div>
<div class="section" id="threadpool-metrics">
<h2>ThreadPool Metrics<a class="headerlink" href="#threadpool-metrics" title="Permalink to this headline">¶</a></h2>
<p>Cassandra splits work of a particular type into its own thread pool.  This provides back-pressure and asynchrony for
requests on a node.  It’s important to monitor the state of these thread pools since they can tell you how saturated a
node is.</p>
<p>The metric names are all appended with the specific <code class="docutils literal notranslate"><span class="pre">ThreadPool</span></code> name.  The thread pools are also categorized under a
specific type.</p>
<p>Reported name format:</p>
<dl class="docutils">
<dt><strong>Metric Name</strong></dt>
<dd><code class="docutils literal notranslate"><span class="pre">org.apache.cassandra.metrics.ThreadPools.&lt;MetricName&gt;.&lt;Path&gt;.&lt;ThreadPoolName&gt;</span></code></dd>
<dt><strong>JMX MBean</strong></dt>
<dd><code class="docutils literal notranslate"><span class="pre">org.apache.cassandra.metrics:type=ThreadPools</span> <span class="pre">path=&lt;Path&gt;</span> <span class="pre">scope=&lt;ThreadPoolName&gt;</span> <span class="pre">name=&lt;MetricName&gt;</span></code></dd>
</dl>
<table border="1" class="docutils">
<colgroup>
<col width="15%" />
<col width="10%" />
<col width="74%" />
</colgroup>
<thead valign="bottom">
<tr class="row-odd"><th class="head">Name</th>
<th class="head">Type</th>
<th class="head">Description</th>
</tr>
</thead>
<tbody valign="top">
<tr class="row-even"><td>ActiveTasks</td>
<td>Gauge&lt;Integer&gt;</td>
<td>Number of tasks being actively worked on by this pool.</td>
</tr>
<tr class="row-odd"><td>PendingTasks</td>
<td>Gauge&lt;Integer&gt;</td>
<td>Number of queued tasks queued up on this pool.</td>
</tr>
<tr class="row-even"><td>CompletedTasks</td>
<td>Counter</td>
<td>Number of tasks completed.</td>
</tr>
<tr class="row-odd"><td>TotalBlockedTasks</td>
<td>Counter</td>
<td>Number of tasks that were blocked due to queue saturation.</td>
</tr>
<tr class="row-even"><td>CurrentlyBlockedTask</td>
<td>Counter</td>
<td>Number of tasks that are currently blocked due to queue saturation but on retry will become unblocked.</td>
</tr>
<tr class="row-odd"><td>MaxPoolSize</td>
<td>Gauge&lt;Integer&gt;</td>
<td>The maximum number of threads in this pool.</td>
</tr>
<tr class="row-even"><td>MaxTasksQueued</td>
<td>Gauge&lt;Integer&gt;</td>
<td>The maximum number of tasks queued before a task get blocked.</td>
</tr>
</tbody>
</table>
<p>The following thread pools can be monitored.</p>
<table border="1" class="docutils">
<colgroup>
<col width="26%" />
<col width="13%" />
<col width="61%" />
</colgroup>
<thead valign="bottom">
<tr class="row-odd"><th class="head">Name</th>
<th class="head">Type</th>
<th class="head">Description</th>
</tr>
</thead>
<tbody valign="top">
<tr class="row-even"><td>Native-Transport-Requests</td>
<td>transport</td>
<td>Handles client CQL requests</td>
</tr>
<tr class="row-odd"><td>CounterMutationStage</td>
<td>request</td>
<td>Responsible for counter writes</td>
</tr>
<tr class="row-even"><td>ViewMutationStage</td>
<td>request</td>
<td>Responsible for materialized view writes</td>
</tr>
<tr class="row-odd"><td>MutationStage</td>
<td>request</td>
<td>Responsible for all other writes</td>
</tr>
<tr class="row-even"><td>ReadRepairStage</td>
<td>request</td>
<td>ReadRepair happens on this thread pool</td>
</tr>
<tr class="row-odd"><td>ReadStage</td>
<td>request</td>
<td>Local reads run on this thread pool</td>
</tr>
<tr class="row-even"><td>RequestResponseStage</td>
<td>request</td>
<td>Coordinator requests to the cluster run on this thread pool</td>
</tr>
<tr class="row-odd"><td>AntiEntropyStage</td>
<td>internal</td>
<td>Builds merkle tree for repairs</td>
</tr>
<tr class="row-even"><td>CacheCleanupExecutor</td>
<td>internal</td>
<td>Cache maintenance performed on this thread pool</td>
</tr>
<tr class="row-odd"><td>CompactionExecutor</td>
<td>internal</td>
<td>Compactions are run on these threads</td>
</tr>
<tr class="row-even"><td>GossipStage</td>
<td>internal</td>
<td>Handles gossip requests</td>
</tr>
<tr class="row-odd"><td>HintsDispatcher</td>
<td>internal</td>
<td>Performs hinted handoff</td>
</tr>
<tr class="row-even"><td>InternalResponseStage</td>
<td>internal</td>
<td>Responsible for intra-cluster callbacks</td>
</tr>
<tr class="row-odd"><td>MemtableFlushWriter</td>
<td>internal</td>
<td>Writes memtables to disk</td>
</tr>
<tr class="row-even"><td>MemtablePostFlush</td>
<td>internal</td>
<td>Cleans up commit log after memtable is written to disk</td>
</tr>
<tr class="row-odd"><td>MemtableReclaimMemory</td>
<td>internal</td>
<td>Memtable recycling</td>
</tr>
<tr class="row-even"><td>MigrationStage</td>
<td>internal</td>
<td>Runs schema migrations</td>
</tr>
<tr class="row-odd"><td>MiscStage</td>
<td>internal</td>
<td>Misceleneous tasks run here</td>
</tr>
<tr class="row-even"><td>PendingRangeCalculator</td>
<td>internal</td>
<td>Calculates token range</td>
</tr>
<tr class="row-odd"><td>PerDiskMemtableFlushWriter_0</td>
<td>internal</td>
<td>Responsible for writing a spec (there is one of these per disk 0-N)</td>
</tr>
<tr class="row-even"><td>Sampler</td>
<td>internal</td>
<td>Responsible for re-sampling the index summaries of SStables</td>
</tr>
<tr class="row-odd"><td>SecondaryIndexManagement</td>
<td>internal</td>
<td>Performs updates to secondary indexes</td>
</tr>
<tr class="row-even"><td>ValidationExecutor</td>
<td>internal</td>
<td>Performs validation compaction or scrubbing</td>
</tr>
<tr class="row-odd"><td>ViewBuildExecutor</td>
<td>internal</td>
<td>Performs materialized views initial build</td>
</tr>
</tbody>
</table>
</div>
<div class="section" id="client-request-metrics">
<h2>Client Request Metrics<a class="headerlink" href="#client-request-metrics" title="Permalink to this headline">¶</a></h2>
<p>Client requests have their own set of metrics that encapsulate the work happening at coordinator level.</p>
<p>Different types of client requests are broken down by <code class="docutils literal notranslate"><span class="pre">RequestType</span></code>.</p>
<p>Reported name format:</p>
<dl class="docutils">
<dt><strong>Metric Name</strong></dt>
<dd><code class="docutils literal notranslate"><span class="pre">org.apache.cassandra.metrics.ClientRequest.&lt;MetricName&gt;.&lt;RequestType&gt;</span></code></dd>
<dt><strong>JMX MBean</strong></dt>
<dd><code class="docutils literal notranslate"><span class="pre">org.apache.cassandra.metrics:type=ClientRequest</span> <span class="pre">scope=&lt;RequestType&gt;</span> <span class="pre">name=&lt;MetricName&gt;</span></code></dd>
</dl>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">RequestType:</th><td class="field-body"><p class="first">CASRead</p>
</td>
</tr>
<tr class="field-even field"><th class="field-name">Description:</th><td class="field-body"><p class="first">Metrics related to transactional read requests.</p>
</td>
</tr>
<tr class="field-odd field"><th class="field-name">Metrics:</th><td class="field-body"><table border="1" class="first docutils">
<colgroup>
<col width="21%" />
<col width="14%" />
<col width="65%" />
</colgroup>
<thead valign="bottom">
<tr class="row-odd"><th class="head">Name</th>
<th class="head">Type</th>
<th class="head">Description</th>
</tr>
</thead>
<tbody valign="top">
<tr class="row-even"><td>Timeouts</td>
<td>Counter</td>
<td>Number of timeouts encountered.</td>
</tr>
<tr class="row-odd"><td>Failures</td>
<td>Counter</td>
<td>Number of transaction failures encountered.</td>
</tr>
<tr class="row-even"><td>&nbsp;</td>
<td>Latency</td>
<td>Transaction read latency.</td>
</tr>
<tr class="row-odd"><td>Unavailables</td>
<td>Counter</td>
<td>Number of unavailable exceptions encountered.</td>
</tr>
<tr class="row-even"><td>UnfinishedCommit</td>
<td>Counter</td>
<td>Number of transactions that were committed on read.</td>
</tr>
<tr class="row-odd"><td>ConditionNotMet</td>
<td>Counter</td>
<td>Number of transaction preconditions did not match current values.</td>
</tr>
<tr class="row-even"><td>ContentionHistogram</td>
<td>Histogram</td>
<td>How many contended reads were encountered</td>
</tr>
</tbody>
</table>
</td>
</tr>
<tr class="field-even field"><th class="field-name">RequestType:</th><td class="field-body"><p class="first">CASWrite</p>
</td>
</tr>
<tr class="field-odd field"><th class="field-name">Description:</th><td class="field-body"><p class="first">Metrics related to transactional write requests.</p>
</td>
</tr>
<tr class="field-even field"><th class="field-name">Metrics:</th><td class="field-body"><table border="1" class="first docutils">
<colgroup>
<col width="21%" />
<col width="14%" />
<col width="65%" />
</colgroup>
<thead valign="bottom">
<tr class="row-odd"><th class="head">Name</th>
<th class="head">Type</th>
<th class="head">Description</th>
</tr>
</thead>
<tbody valign="top">
<tr class="row-even"><td>Timeouts</td>
<td>Counter</td>
<td>Number of timeouts encountered.</td>
</tr>
<tr class="row-odd"><td>Failures</td>
<td>Counter</td>
<td>Number of transaction failures encountered.</td>
</tr>
<tr class="row-even"><td>&nbsp;</td>
<td>Latency</td>
<td>Transaction write latency.</td>
</tr>
<tr class="row-odd"><td>UnfinishedCommit</td>
<td>Counter</td>
<td>Number of transactions that were committed on write.</td>
</tr>
<tr class="row-even"><td>ConditionNotMet</td>
<td>Counter</td>
<td>Number of transaction preconditions did not match current values.</td>
</tr>
<tr class="row-odd"><td>ContentionHistogram</td>
<td>Histogram</td>
<td>How many contended writes were encountered</td>
</tr>
<tr class="row-even"><td>MutationSizeHistogram</td>
<td>Histogram</td>
<td>Total size in bytes of the requests mutations.</td>
</tr>
</tbody>
</table>
</td>
</tr>
<tr class="field-odd field"><th class="field-name">RequestType:</th><td class="field-body"><p class="first">Read</p>
</td>
</tr>
<tr class="field-even field"><th class="field-name">Description:</th><td class="field-body"><p class="first">Metrics related to standard read requests.</p>
</td>
</tr>
<tr class="field-odd field"><th class="field-name">Metrics:</th><td class="field-body"><table border="1" class="first docutils">
<colgroup>
<col width="22%" />
<col width="15%" />
<col width="64%" />
</colgroup>
<thead valign="bottom">
<tr class="row-odd"><th class="head">Name</th>
<th class="head">Type</th>
<th class="head">Description</th>
</tr>
</thead>
<tbody valign="top">
<tr class="row-even"><td>Timeouts</td>
<td>Counter</td>
<td>Number of timeouts encountered.</td>
</tr>
<tr class="row-odd"><td>Failures</td>
<td>Counter</td>
<td>Number of read failures encountered.</td>
</tr>
<tr class="row-even"><td>&nbsp;</td>
<td>Latency</td>
<td>Read latency.</td>
</tr>
<tr class="row-odd"><td>Unavailables</td>
<td>Counter</td>
<td>Number of unavailable exceptions encountered.</td>
</tr>
</tbody>
</table>
</td>
</tr>
<tr class="field-even field"><th class="field-name">RequestType:</th><td class="field-body"><p class="first">RangeSlice</p>
</td>
</tr>
<tr class="field-odd field"><th class="field-name">Description:</th><td class="field-body"><p class="first">Metrics related to token range read requests.</p>
</td>
</tr>
<tr class="field-even field"><th class="field-name">Metrics:</th><td class="field-body"><table border="1" class="first docutils">
<colgroup>
<col width="22%" />
<col width="15%" />
<col width="64%" />
</colgroup>
<thead valign="bottom">
<tr class="row-odd"><th class="head">Name</th>
<th class="head">Type</th>
<th class="head">Description</th>
</tr>
</thead>
<tbody valign="top">
<tr class="row-even"><td>Timeouts</td>
<td>Counter</td>
<td>Number of timeouts encountered.</td>
</tr>
<tr class="row-odd"><td>Failures</td>
<td>Counter</td>
<td>Number of range query failures encountered.</td>
</tr>
<tr class="row-even"><td>&nbsp;</td>
<td>Latency</td>
<td>Range query latency.</td>
</tr>
<tr class="row-odd"><td>Unavailables</td>
<td>Counter</td>
<td>Number of unavailable exceptions encountered.</td>
</tr>
</tbody>
</table>
</td>
</tr>
<tr class="field-odd field"><th class="field-name">RequestType:</th><td class="field-body"><p class="first">Write</p>
</td>
</tr>
<tr class="field-even field"><th class="field-name">Description:</th><td class="field-body"><p class="first">Metrics related to regular write requests.</p>
</td>
</tr>
<tr class="field-odd field"><th class="field-name">Metrics:</th><td class="field-body"><table border="1" class="first docutils">
<colgroup>
<col width="22%" />
<col width="15%" />
<col width="64%" />
</colgroup>
<thead valign="bottom">
<tr class="row-odd"><th class="head">Name</th>
<th class="head">Type</th>
<th class="head">Description</th>
</tr>
</thead>
<tbody valign="top">
<tr class="row-even"><td>Timeouts</td>
<td>Counter</td>
<td>Number of timeouts encountered.</td>
</tr>
<tr class="row-odd"><td>Failures</td>
<td>Counter</td>
<td>Number of write failures encountered.</td>
</tr>
<tr class="row-even"><td>&nbsp;</td>
<td>Latency</td>
<td>Write latency.</td>
</tr>
<tr class="row-odd"><td>Unavailables</td>
<td>Counter</td>
<td>Number of unavailable exceptions encountered.</td>
</tr>
<tr class="row-even"><td>MutationSizeHistogram</td>
<td>Histogram</td>
<td>Total size in bytes of the requests mutations.</td>
</tr>
</tbody>
</table>
</td>
</tr>
<tr class="field-even field"><th class="field-name">RequestType:</th><td class="field-body"><p class="first">ViewWrite</p>
</td>
</tr>
<tr class="field-odd field"><th class="field-name">Description:</th><td class="field-body"><p class="first">Metrics related to materialized view write wrtes.</p>
</td>
</tr>
<tr class="field-even field"><th class="field-name">Metrics:</th><td class="field-body"><table border="1" class="first last docutils">
<colgroup>
<col width="17%" />
<col width="11%" />
<col width="72%" />
</colgroup>
<tbody valign="top">
<tr class="row-odd"><td>Timeouts</td>
<td>Counter</td>
<td>Number of timeouts encountered.</td>
</tr>
<tr class="row-even"><td>Failures</td>
<td>Counter</td>
<td>Number of transaction failures encountered.</td>
</tr>
<tr class="row-odd"><td>Unavailables</td>
<td>Counter</td>
<td>Number of unavailable exceptions encountered.</td>
</tr>
<tr class="row-even"><td>ViewReplicasAttempted</td>
<td>Counter</td>
<td>Total number of attempted view replica writes.</td>
</tr>
<tr class="row-odd"><td>ViewReplicasSuccess</td>
<td>Counter</td>
<td>Total number of succeded view replica writes.</td>
</tr>
<tr class="row-even"><td>ViewPendingMutations</td>
<td>Gauge&lt;Long&gt;</td>
<td>ViewReplicasAttempted - ViewReplicasSuccess.</td>
</tr>
<tr class="row-odd"><td>ViewWriteLatency</td>
<td>Timer</td>
<td>Time between when mutation is applied to base table and when CL.ONE is achieved on view.</td>
</tr>
</tbody>
</table>
</td>
</tr>
</tbody>
</table>
</div>
<div class="section" id="cache-metrics">
<h2>Cache Metrics<a class="headerlink" href="#cache-metrics" title="Permalink to this headline">¶</a></h2>
<p>Cassandra caches have metrics to track the effectivness of the caches. Though the <code class="docutils literal notranslate"><span class="pre">Table</span> <span class="pre">Metrics</span></code> might be more useful.</p>
<p>Reported name format:</p>
<dl class="docutils">
<dt><strong>Metric Name</strong></dt>
<dd><code class="docutils literal notranslate"><span class="pre">org.apache.cassandra.metrics.Cache.&lt;MetricName&gt;.&lt;CacheName&gt;</span></code></dd>
<dt><strong>JMX MBean</strong></dt>
<dd><code class="docutils literal notranslate"><span class="pre">org.apache.cassandra.metrics:type=Cache</span> <span class="pre">scope=&lt;CacheName&gt;</span> <span class="pre">name=&lt;MetricName&gt;</span></code></dd>
</dl>
<table border="1" class="docutils">
<colgroup>
<col width="33%" />
<col width="18%" />
<col width="49%" />
</colgroup>
<thead valign="bottom">
<tr class="row-odd"><th class="head">Name</th>
<th class="head">Type</th>
<th class="head">Description</th>
</tr>
</thead>
<tbody valign="top">
<tr class="row-even"><td>Capacity</td>
<td>Gauge&lt;Long&gt;</td>
<td>Cache capacity in bytes.</td>
</tr>
<tr class="row-odd"><td>Entries</td>
<td>Gauge&lt;Integer&gt;</td>
<td>Total number of cache entries.</td>
</tr>
<tr class="row-even"><td>FifteenMinuteCacheHitRate</td>
<td>Gauge&lt;Double&gt;</td>
<td>15m cache hit rate.</td>
</tr>
<tr class="row-odd"><td>FiveMinuteCacheHitRate</td>
<td>Gauge&lt;Double&gt;</td>
<td>5m cache hit rate.</td>
</tr>
<tr class="row-even"><td>OneMinuteCacheHitRate</td>
<td>Gauge&lt;Double&gt;</td>
<td>1m cache hit rate.</td>
</tr>
<tr class="row-odd"><td>HitRate</td>
<td>Gauge&lt;Double&gt;</td>
<td>All time cache hit rate.</td>
</tr>
<tr class="row-even"><td>Hits</td>
<td>Meter</td>
<td>Total number of cache hits.</td>
</tr>
<tr class="row-odd"><td>Misses</td>
<td>Meter</td>
<td>Total number of cache misses.</td>
</tr>
<tr class="row-even"><td>MissLatency</td>
<td>Timer</td>
<td>Latency of misses.</td>
</tr>
<tr class="row-odd"><td>Requests</td>
<td>Gauge&lt;Long&gt;</td>
<td>Total number of cache requests.</td>
</tr>
<tr class="row-even"><td>Size</td>
<td>Gauge&lt;Long&gt;</td>
<td>Total size of occupied cache, in bytes.</td>
</tr>
</tbody>
</table>
<p>The following caches are covered:</p>
<table border="1" class="docutils">
<colgroup>
<col width="38%" />
<col width="62%" />
</colgroup>
<thead valign="bottom">
<tr class="row-odd"><th class="head">Name</th>
<th class="head">Description</th>
</tr>
</thead>
<tbody valign="top">
<tr class="row-even"><td>CounterCache</td>
<td>Keeps hot counters in memory for performance.</td>
</tr>
<tr class="row-odd"><td>ChunkCache</td>
<td>In process uncompressed page cache.</td>
</tr>
<tr class="row-even"><td>KeyCache</td>
<td>Cache for partition to sstable offsets.</td>
</tr>
<tr class="row-odd"><td>RowCache</td>
<td>Cache for rows kept in memory.</td>
</tr>
</tbody>
</table>
<div class="admonition note">
<p class="first admonition-title">Note</p>
<p class="last">Misses and MissLatency are only defined for the ChunkCache</p>
</div>
</div>
<div class="section" id="cql-metrics">
<h2>CQL Metrics<a class="headerlink" href="#cql-metrics" title="Permalink to this headline">¶</a></h2>
<p>Metrics specific to CQL prepared statement caching.</p>
<p>Reported name format:</p>
<dl class="docutils">
<dt><strong>Metric Name</strong></dt>
<dd><code class="docutils literal notranslate"><span class="pre">org.apache.cassandra.metrics.CQL.&lt;MetricName&gt;</span></code></dd>
<dt><strong>JMX MBean</strong></dt>
<dd><code class="docutils literal notranslate"><span class="pre">org.apache.cassandra.metrics:type=CQL</span> <span class="pre">name=&lt;MetricName&gt;</span></code></dd>
</dl>
<table border="1" class="docutils">
<colgroup>
<col width="23%" />
<col width="13%" />
<col width="64%" />
</colgroup>
<thead valign="bottom">
<tr class="row-odd"><th class="head">Name</th>
<th class="head">Type</th>
<th class="head">Description</th>
</tr>
</thead>
<tbody valign="top">
<tr class="row-even"><td>PreparedStatementsCount</td>
<td>Gauge&lt;Integer&gt;</td>
<td>Number of cached prepared statements.</td>
</tr>
<tr class="row-odd"><td>PreparedStatementsEvicted</td>
<td>Counter</td>
<td>Number of prepared statements evicted from the prepared statement cache</td>
</tr>
<tr class="row-even"><td>PreparedStatementsExecuted</td>
<td>Counter</td>
<td>Number of prepared statements executed.</td>
</tr>
<tr class="row-odd"><td>RegularStatementsExecuted</td>
<td>Counter</td>
<td>Number of <strong>non</strong> prepared statements executed.</td>
</tr>
<tr class="row-even"><td>PreparedStatementsRatio</td>
<td>Gauge&lt;Double&gt;</td>
<td>Percentage of statements that are prepared vs unprepared.</td>
</tr>
</tbody>
</table>
</div>
<div class="section" id="droppedmessage-metrics">
<span id="dropped-metrics"></span><h2>DroppedMessage Metrics<a class="headerlink" href="#droppedmessage-metrics" title="Permalink to this headline">¶</a></h2>
<p>Metrics specific to tracking dropped messages for different types of requests.
Dropped writes are stored and retried by <code class="docutils literal notranslate"><span class="pre">Hinted</span> <span class="pre">Handoff</span></code></p>
<p>Reported name format:</p>
<dl class="docutils">
<dt><strong>Metric Name</strong></dt>
<dd><code class="docutils literal notranslate"><span class="pre">org.apache.cassandra.metrics.DroppedMessage.&lt;MetricName&gt;.&lt;Type&gt;</span></code></dd>
<dt><strong>JMX MBean</strong></dt>
<dd><code class="docutils literal notranslate"><span class="pre">org.apache.cassandra.metrics:type=DroppedMessage</span> <span class="pre">scope=&lt;Type&gt;</span> <span class="pre">name=&lt;MetricName&gt;</span></code></dd>
</dl>
<table border="1" class="docutils">
<colgroup>
<col width="36%" />
<col width="19%" />
<col width="45%" />
</colgroup>
<thead valign="bottom">
<tr class="row-odd"><th class="head">Name</th>
<th class="head">Type</th>
<th class="head">Description</th>
</tr>
</thead>
<tbody valign="top">
<tr class="row-even"><td>CrossNodeDroppedLatency</td>
<td>Timer</td>
<td>The dropped latency across nodes.</td>
</tr>
<tr class="row-odd"><td>InternalDroppedLatency</td>
<td>Timer</td>
<td>The dropped latency within node.</td>
</tr>
<tr class="row-even"><td>Dropped</td>
<td>Meter</td>
<td>Number of dropped messages.</td>
</tr>
</tbody>
</table>
<p>The different types of messages tracked are:</p>
<table border="1" class="docutils">
<colgroup>
<col width="39%" />
<col width="61%" />
</colgroup>
<thead valign="bottom">
<tr class="row-odd"><th class="head">Name</th>
<th class="head">Description</th>
</tr>
</thead>
<tbody valign="top">
<tr class="row-even"><td>BATCH_STORE</td>
<td>Batchlog write</td>
</tr>
<tr class="row-odd"><td>BATCH_REMOVE</td>
<td>Batchlog cleanup (after succesfully applied)</td>
</tr>
<tr class="row-even"><td>COUNTER_MUTATION</td>
<td>Counter writes</td>
</tr>
<tr class="row-odd"><td>HINT</td>
<td>Hint replay</td>
</tr>
<tr class="row-even"><td>MUTATION</td>
<td>Regular writes</td>
</tr>
<tr class="row-odd"><td>READ</td>
<td>Regular reads</td>
</tr>
<tr class="row-even"><td>READ_REPAIR</td>
<td>Read repair</td>
</tr>
<tr class="row-odd"><td>PAGED_SLICE</td>
<td>Paged read</td>
</tr>
<tr class="row-even"><td>RANGE_SLICE</td>
<td>Token range read</td>
</tr>
<tr class="row-odd"><td>REQUEST_RESPONSE</td>
<td>RPC Callbacks</td>
</tr>
<tr class="row-even"><td>_TRACE</td>
<td>Tracing writes</td>
</tr>
</tbody>
</table>
</div>
<div class="section" id="streaming-metrics">
<h2>Streaming Metrics<a class="headerlink" href="#streaming-metrics" title="Permalink to this headline">¶</a></h2>
<p>Metrics reported during <code class="docutils literal notranslate"><span class="pre">Streaming</span></code> operations, such as repair, bootstrap, rebuild.</p>
<p>These metrics are specific to a peer endpoint, with the source node being the node you are pulling the metrics from.</p>
<p>Reported name format:</p>
<dl class="docutils">
<dt><strong>Metric Name</strong></dt>
<dd><code class="docutils literal notranslate"><span class="pre">org.apache.cassandra.metrics.Streaming.&lt;MetricName&gt;.&lt;PeerIP&gt;</span></code></dd>
<dt><strong>JMX MBean</strong></dt>
<dd><code class="docutils literal notranslate"><span class="pre">org.apache.cassandra.metrics:type=Streaming</span> <span class="pre">scope=&lt;PeerIP&gt;</span> <span class="pre">name=&lt;MetricName&gt;</span></code></dd>
</dl>
<table border="1" class="docutils">
<colgroup>
<col width="26%" />
<col width="14%" />
<col width="60%" />
</colgroup>
<thead valign="bottom">
<tr class="row-odd"><th class="head">Name</th>
<th class="head">Type</th>
<th class="head">Description</th>
</tr>
</thead>
<tbody valign="top">
<tr class="row-even"><td>IncomingBytes</td>
<td>Counter</td>
<td>Number of bytes streamed to this node from the peer.</td>
</tr>
<tr class="row-odd"><td>OutgoingBytes</td>
<td>Counter</td>
<td>Number of bytes streamed to the peer endpoint from this node.</td>
</tr>
</tbody>
</table>
</div>
<div class="section" id="compaction-metrics">
<h2>Compaction Metrics<a class="headerlink" href="#compaction-metrics" title="Permalink to this headline">¶</a></h2>
<p>Metrics specific to <code class="docutils literal notranslate"><span class="pre">Compaction</span></code> work.</p>
<p>Reported name format:</p>
<dl class="docutils">
<dt><strong>Metric Name</strong></dt>
<dd><code class="docutils literal notranslate"><span class="pre">org.apache.cassandra.metrics.Compaction.&lt;MetricName&gt;</span></code></dd>
<dt><strong>JMX MBean</strong></dt>
<dd><code class="docutils literal notranslate"><span class="pre">org.apache.cassandra.metrics:type=Compaction</span> <span class="pre">name=&lt;MetricName&gt;</span></code></dd>
</dl>
<table border="1" class="docutils">
<colgroup>
<col width="13%" />
<col width="20%" />
<col width="68%" />
</colgroup>
<thead valign="bottom">
<tr class="row-odd"><th class="head">Name</th>
<th class="head">Type</th>
<th class="head">Description</th>
</tr>
</thead>
<tbody valign="top">
<tr class="row-even"><td>BytesCompacted</td>
<td>Counter</td>
<td>Total number of bytes compacted since server [re]start.</td>
</tr>
<tr class="row-odd"><td>PendingTasks</td>
<td>Gauge&lt;Integer&gt;</td>
<td>Estimated number of compactions remaining to perform.</td>
</tr>
<tr class="row-even"><td>CompletedTasks</td>
<td>Gauge&lt;Long&gt;</td>
<td>Number of completed compactions since server [re]start.</td>
</tr>
<tr class="row-odd"><td>TotalCompactionsCompleted</td>
<td>Meter</td>
<td>Throughput of completed compactions since server [re]start.</td>
</tr>
<tr class="row-even"><td>PendingTasksByTableName</td>
<td>Gauge&lt;Map&lt;String, Map&lt;String, Integer&gt;&gt;&gt;</td>
<td>Estimated number of compactions remaining to perform, grouped by keyspace and then table name. This info is also kept in <code class="docutils literal notranslate"><span class="pre">Table</span> <span class="pre">Metrics</span></code>.</td>
</tr>
</tbody>
</table>
</div>
<div class="section" id="commitlog-metrics">
<h2>CommitLog Metrics<a class="headerlink" href="#commitlog-metrics" title="Permalink to this headline">¶</a></h2>
<p>Metrics specific to the <code class="docutils literal notranslate"><span class="pre">CommitLog</span></code></p>
<p>Reported name format:</p>
<dl class="docutils">
<dt><strong>Metric Name</strong></dt>
<dd><code class="docutils literal notranslate"><span class="pre">org.apache.cassandra.metrics.CommitLog.&lt;MetricName&gt;</span></code></dd>
<dt><strong>JMX MBean</strong></dt>
<dd><code class="docutils literal notranslate"><span class="pre">org.apache.cassandra.metrics:type=CommitLog</span> <span class="pre">name=&lt;MetricName&gt;</span></code></dd>
</dl>
<table border="1" class="docutils">
<colgroup>
<col width="17%" />
<col width="9%" />
<col width="74%" />
</colgroup>
<thead valign="bottom">
<tr class="row-odd"><th class="head">Name</th>
<th class="head">Type</th>
<th class="head">Description</th>
</tr>
</thead>
<tbody valign="top">
<tr class="row-even"><td>CompletedTasks</td>
<td>Gauge&lt;Long&gt;</td>
<td>Total number of commit log messages written since [re]start.</td>
</tr>
<tr class="row-odd"><td>PendingTasks</td>
<td>Gauge&lt;Long&gt;</td>
<td>Number of commit log messages written but yet to be fsync’d.</td>
</tr>
<tr class="row-even"><td>TotalCommitLogSize</td>
<td>Gauge&lt;Long&gt;</td>
<td>Current size, in bytes, used by all the commit log segments.</td>
</tr>
<tr class="row-odd"><td>WaitingOnSegmentAllocation</td>
<td>Timer</td>
<td>Time spent waiting for a CommitLogSegment to be allocated - under normal conditions this should be zero.</td>
</tr>
<tr class="row-even"><td>WaitingOnCommit</td>
<td>Timer</td>
<td>The time spent waiting on CL fsync; for Periodic this is only occurs when the sync is lagging its sync interval.</td>
</tr>
</tbody>
</table>
</div>
<div class="section" id="storage-metrics">
<h2>Storage Metrics<a class="headerlink" href="#storage-metrics" title="Permalink to this headline">¶</a></h2>
<p>Metrics specific to the storage engine.</p>
<p>Reported name format:</p>
<dl class="docutils">
<dt><strong>Metric Name</strong></dt>
<dd><code class="docutils literal notranslate"><span class="pre">org.apache.cassandra.metrics.Storage.&lt;MetricName&gt;</span></code></dd>
<dt><strong>JMX MBean</strong></dt>
<dd><code class="docutils literal notranslate"><span class="pre">org.apache.cassandra.metrics:type=Storage</span> <span class="pre">name=&lt;MetricName&gt;</span></code></dd>
</dl>
<table border="1" class="docutils">
<colgroup>
<col width="17%" />
<col width="9%" />
<col width="75%" />
</colgroup>
<thead valign="bottom">
<tr class="row-odd"><th class="head">Name</th>
<th class="head">Type</th>
<th class="head">Description</th>
</tr>
</thead>
<tbody valign="top">
<tr class="row-even"><td>Exceptions</td>
<td>Counter</td>
<td>Number of internal exceptions caught. Under normal exceptions this should be zero.</td>
</tr>
<tr class="row-odd"><td>Load</td>
<td>Counter</td>
<td>Size, in bytes, of the on disk data size this node manages.</td>
</tr>
<tr class="row-even"><td>TotalHints</td>
<td>Counter</td>
<td>Number of hint messages written to this node since [re]start. Includes one entry for each host to be hinted per hint.</td>
</tr>
<tr class="row-odd"><td>TotalHintsInProgress</td>
<td>Counter</td>
<td>Number of hints attemping to be sent currently.</td>
</tr>
</tbody>
</table>
</div>
<div class="section" id="hintsservice-metrics">
<span id="id2"></span><h2>HintsService Metrics<a class="headerlink" href="#hintsservice-metrics" title="Permalink to this headline">¶</a></h2>
<p>Metrics specific to the Hints delivery service.  There are also some metrics related to hints tracked in <code class="docutils literal notranslate"><span class="pre">Storage</span> <span class="pre">Metrics</span></code></p>
<p>These metrics include the peer endpoint <strong>in the metric name</strong></p>
<p>Reported name format:</p>
<dl class="docutils">
<dt><strong>Metric Name</strong></dt>
<dd><code class="docutils literal notranslate"><span class="pre">org.apache.cassandra.metrics.HintsService.&lt;MetricName&gt;</span></code></dd>
<dt><strong>JMX MBean</strong></dt>
<dd><code class="docutils literal notranslate"><span class="pre">org.apache.cassandra.metrics:type=HintsService</span> <span class="pre">name=&lt;MetricName&gt;</span></code></dd>
</dl>
<table border="1" class="docutils">
<colgroup>
<col width="27%" />
<col width="14%" />
<col width="59%" />
</colgroup>
<thead valign="bottom">
<tr class="row-odd"><th class="head">Name</th>
<th class="head">Type</th>
<th class="head">Description</th>
</tr>
</thead>
<tbody valign="top">
<tr class="row-even"><td>HintsSucceeded</td>
<td>Meter</td>
<td>A meter of the hints successfully delivered</td>
</tr>
<tr class="row-odd"><td>HintsFailed</td>
<td>Meter</td>
<td>A meter of the hints that failed deliver</td>
</tr>
<tr class="row-even"><td>HintsTimedOut</td>
<td>Meter</td>
<td>A meter of the hints that timed out</td>
</tr>
<tr class="row-odd"><td>Hint_delays</td>
<td>Histogram</td>
<td>Histogram of hint delivery delays (in milliseconds)</td>
</tr>
<tr class="row-even"><td>Hint_delays-&lt;PeerIP&gt;</td>
<td>Histogram</td>
<td>Histogram of hint delivery delays (in milliseconds) per peer</td>
</tr>
</tbody>
</table>
</div>
<div class="section" id="sstable-index-metrics">
<h2>SSTable Index Metrics<a class="headerlink" href="#sstable-index-metrics" title="Permalink to this headline">¶</a></h2>
<p>Metrics specific to the SSTable index metadata.</p>
<p>Reported name format:</p>
<dl class="docutils">
<dt><strong>Metric Name</strong></dt>
<dd><code class="docutils literal notranslate"><span class="pre">org.apache.cassandra.metrics.Index.&lt;MetricName&gt;.RowIndexEntry</span></code></dd>
<dt><strong>JMX MBean</strong></dt>
<dd><code class="docutils literal notranslate"><span class="pre">org.apache.cassandra.metrics:type=Index</span> <span class="pre">scope=RowIndexEntry</span> <span class="pre">name=&lt;MetricName&gt;</span></code></dd>
</dl>
<table border="1" class="docutils">
<colgroup>
<col width="23%" />
<col width="12%" />
<col width="65%" />
</colgroup>
<thead valign="bottom">
<tr class="row-odd"><th class="head">Name</th>
<th class="head">Type</th>
<th class="head">Description</th>
</tr>
</thead>
<tbody valign="top">
<tr class="row-even"><td>IndexedEntrySize</td>
<td>Histogram</td>
<td>Histogram of the on-heap size, in bytes, of the index across all SSTables.</td>
</tr>
<tr class="row-odd"><td>IndexInfoCount</td>
<td>Histogram</td>
<td>Histogram of the number of on-heap index entries managed across all SSTables.</td>
</tr>
<tr class="row-even"><td>IndexInfoGets</td>
<td>Histogram</td>
<td>Histogram of the number index seeks performed per SSTable.</td>
</tr>
</tbody>
</table>
</div>
<div class="section" id="bufferpool-metrics">
<h2>BufferPool Metrics<a class="headerlink" href="#bufferpool-metrics" title="Permalink to this headline">¶</a></h2>
<p>Metrics specific to the internal recycled buffer pool Cassandra manages.  This pool is meant to keep allocations and GC
lower by recycling on and off heap buffers.</p>
<p>Reported name format:</p>
<dl class="docutils">
<dt><strong>Metric Name</strong></dt>
<dd><code class="docutils literal notranslate"><span class="pre">org.apache.cassandra.metrics.BufferPool.&lt;MetricName&gt;</span></code></dd>
<dt><strong>JMX MBean</strong></dt>
<dd><code class="docutils literal notranslate"><span class="pre">org.apache.cassandra.metrics:type=BufferPool</span> <span class="pre">name=&lt;MetricName&gt;</span></code></dd>
</dl>
<table border="1" class="docutils">
<colgroup>
<col width="22%" />
<col width="11%" />
<col width="67%" />
</colgroup>
<thead valign="bottom">
<tr class="row-odd"><th class="head">Name</th>
<th class="head">Type</th>
<th class="head">Description</th>
</tr>
</thead>
<tbody valign="top">
<tr class="row-even"><td>Size</td>
<td>Gauge&lt;Long&gt;</td>
<td>Size, in bytes, of the managed buffer pool</td>
</tr>
<tr class="row-odd"><td>Misses</td>
<td>Meter</td>
<td>The rate of misses in the pool. The higher this is the more allocations incurred.</td>
</tr>
</tbody>
</table>
</div>
<div class="section" id="client-metrics">
<h2>Client Metrics<a class="headerlink" href="#client-metrics" title="Permalink to this headline">¶</a></h2>
<p>Metrics specifc to client managment.</p>
<p>Reported name format:</p>
<dl class="docutils">
<dt><strong>Metric Name</strong></dt>
<dd><code class="docutils literal notranslate"><span class="pre">org.apache.cassandra.metrics.Client.&lt;MetricName&gt;</span></code></dd>
<dt><strong>JMX MBean</strong></dt>
<dd><code class="docutils literal notranslate"><span class="pre">org.apache.cassandra.metrics:type=Client</span> <span class="pre">name=&lt;MetricName&gt;</span></code></dd>
</dl>
<table border="1" class="docutils">
<colgroup>
<col width="24%" />
<col width="25%" />
<col width="51%" />
</colgroup>
<thead valign="bottom">
<tr class="row-odd"><th class="head">Name</th>
<th class="head">Type</th>
<th class="head">Description</th>
</tr>
</thead>
<tbody valign="top">
<tr class="row-even"><td>connectedNativeClients</td>
<td>Gauge&lt;Integer&gt;</td>
<td>Number of clients connected to this nodes native protocol server</td>
</tr>
<tr class="row-odd"><td>connections</td>
<td>Gauge&lt;List&lt;Map&lt;String, String&gt;&gt;</td>
<td>List of all connections and their state information</td>
</tr>
<tr class="row-even"><td>connectedNativeClientsByUser</td>
<td>Gauge&lt;Map&lt;String, Int&gt;</td>
<td>Number of connnective native clients by username</td>
</tr>
</tbody>
</table>
</div>
<div class="section" id="batch-metrics">
<h2>Batch Metrics<a class="headerlink" href="#batch-metrics" title="Permalink to this headline">¶</a></h2>
<p>Metrics specifc to batch statements.</p>
<p>Reported name format:</p>
<dl class="docutils">
<dt><strong>Metric Name</strong></dt>
<dd><code class="docutils literal notranslate"><span class="pre">org.apache.cassandra.metrics.Batch.&lt;MetricName&gt;</span></code></dd>
<dt><strong>JMX MBean</strong></dt>
<dd><code class="docutils literal notranslate"><span class="pre">org.apache.cassandra.metrics:type=Batch</span> <span class="pre">name=&lt;MetricName&gt;</span></code></dd>
</dl>
<table border="1" class="docutils">
<colgroup>
<col width="25%" />
<col width="13%" />
<col width="63%" />
</colgroup>
<thead valign="bottom">
<tr class="row-odd"><th class="head">Name</th>
<th class="head">Type</th>
<th class="head">Description</th>
</tr>
</thead>
<tbody valign="top">
<tr class="row-even"><td>PartitionsPerCounterBatch</td>
<td>Histogram</td>
<td>Distribution of the number of partitions processed per counter batch</td>
</tr>
<tr class="row-odd"><td>PartitionsPerLoggedBatch</td>
<td>Histogram</td>
<td>Distribution of the number of partitions processed per logged batch</td>
</tr>
<tr class="row-even"><td>PartitionsPerUnloggedBatch</td>
<td>Histogram</td>
<td>Distribution of the number of partitions processed per unlogged batch</td>
</tr>
</tbody>
</table>
</div>
<div class="section" id="jvm-metrics">
<h2>JVM Metrics<a class="headerlink" href="#jvm-metrics" title="Permalink to this headline">¶</a></h2>
<p>JVM metrics such as memory and garbage collection statistics can either be accessed by connecting to the JVM using JMX or can be exported using <a class="reference internal" href="#metric-reporters">Metric Reporters</a>.</p>
<div class="section" id="bufferpool">
<h3>BufferPool<a class="headerlink" href="#bufferpool" title="Permalink to this headline">¶</a></h3>
<dl class="docutils">
<dt><strong>Metric Name</strong></dt>
<dd><code class="docutils literal notranslate"><span class="pre">jvm.buffers.&lt;direct|mapped&gt;.&lt;MetricName&gt;</span></code></dd>
<dt><strong>JMX MBean</strong></dt>
<dd><code class="docutils literal notranslate"><span class="pre">java.nio:type=BufferPool</span> <span class="pre">name=&lt;direct|mapped&gt;</span></code></dd>
</dl>
<table border="1" class="docutils">
<colgroup>
<col width="22%" />
<col width="12%" />
<col width="66%" />
</colgroup>
<thead valign="bottom">
<tr class="row-odd"><th class="head">Name</th>
<th class="head">Type</th>
<th class="head">Description</th>
</tr>
</thead>
<tbody valign="top">
<tr class="row-even"><td>Capacity</td>
<td>Gauge&lt;Long&gt;</td>
<td>Estimated total capacity of the buffers in this pool</td>
</tr>
<tr class="row-odd"><td>Count</td>
<td>Gauge&lt;Long&gt;</td>
<td>Estimated number of buffers in the pool</td>
</tr>
<tr class="row-even"><td>Used</td>
<td>Gauge&lt;Long&gt;</td>
<td>Estimated memory that the Java virtual machine is using for this buffer pool</td>
</tr>
</tbody>
</table>
</div>
<div class="section" id="filedescriptorratio">
<h3>FileDescriptorRatio<a class="headerlink" href="#filedescriptorratio" title="Permalink to this headline">¶</a></h3>
<dl class="docutils">
<dt><strong>Metric Name</strong></dt>
<dd><code class="docutils literal notranslate"><span class="pre">jvm.fd.&lt;MetricName&gt;</span></code></dd>
<dt><strong>JMX MBean</strong></dt>
<dd><code class="docutils literal notranslate"><span class="pre">java.lang:type=OperatingSystem</span> <span class="pre">name=&lt;OpenFileDescriptorCount|MaxFileDescriptorCount&gt;</span></code></dd>
</dl>
<table border="1" class="docutils">
<colgroup>
<col width="33%" />
<col width="18%" />
<col width="49%" />
</colgroup>
<thead valign="bottom">
<tr class="row-odd"><th class="head">Name</th>
<th class="head">Type</th>
<th class="head">Description</th>
</tr>
</thead>
<tbody valign="top">
<tr class="row-even"><td>Usage</td>
<td>Ratio</td>
<td>Ratio of used to total file descriptors</td>
</tr>
</tbody>
</table>
</div>
<div class="section" id="garbagecollector">
<h3>GarbageCollector<a class="headerlink" href="#garbagecollector" title="Permalink to this headline">¶</a></h3>
<dl class="docutils">
<dt><strong>Metric Name</strong></dt>
<dd><code class="docutils literal notranslate"><span class="pre">jvm.gc.&lt;gc_type&gt;.&lt;MetricName&gt;</span></code></dd>
<dt><strong>JMX MBean</strong></dt>
<dd><code class="docutils literal notranslate"><span class="pre">java.lang:type=GarbageCollector</span> <span class="pre">name=&lt;gc_type&gt;</span></code></dd>
</dl>
<table border="1" class="docutils">
<colgroup>
<col width="25%" />
<col width="14%" />
<col width="61%" />
</colgroup>
<thead valign="bottom">
<tr class="row-odd"><th class="head">Name</th>
<th class="head">Type</th>
<th class="head">Description</th>
</tr>
</thead>
<tbody valign="top">
<tr class="row-even"><td>Count</td>
<td>Gauge&lt;Long&gt;</td>
<td>Total number of collections that have occurred</td>
</tr>
<tr class="row-odd"><td>Time</td>
<td>Gauge&lt;Long&gt;</td>
<td>Approximate accumulated collection elapsed time in milliseconds</td>
</tr>
</tbody>
</table>
</div>
<div class="section" id="memory">
<h3>Memory<a class="headerlink" href="#memory" title="Permalink to this headline">¶</a></h3>
<dl class="docutils">
<dt><strong>Metric Name</strong></dt>
<dd><code class="docutils literal notranslate"><span class="pre">jvm.memory.&lt;heap/non-heap/total&gt;.&lt;MetricName&gt;</span></code></dd>
<dt><strong>JMX MBean</strong></dt>
<dd><code class="docutils literal notranslate"><span class="pre">java.lang:type=Memory</span></code></dd>
</dl>
<table border="1" class="docutils">
<colgroup>
<col width="23%" />
<col width="13%" />
<col width="64%" />
</colgroup>
<tbody valign="top">
<tr class="row-odd"><td>Committed</td>
<td>Gauge&lt;Long&gt;</td>
<td>Amount of memory in bytes that is committed for the JVM to use</td>
</tr>
<tr class="row-even"><td>Init</td>
<td>Gauge&lt;Long&gt;</td>
<td>Amount of memory in bytes that the JVM initially requests from the OS</td>
</tr>
<tr class="row-odd"><td>Max</td>
<td>Gauge&lt;Long&gt;</td>
<td>Maximum amount of memory in bytes that can be used for memory management</td>
</tr>
<tr class="row-even"><td>Usage</td>
<td>Ratio</td>
<td>Ratio of used to maximum memory</td>
</tr>
<tr class="row-odd"><td>Used</td>
<td>Gauge&lt;Long&gt;</td>
<td>Amount of used memory in bytes</td>
</tr>
</tbody>
</table>
</div>
<div class="section" id="memorypool">
<h3>MemoryPool<a class="headerlink" href="#memorypool" title="Permalink to this headline">¶</a></h3>
<dl class="docutils">
<dt><strong>Metric Name</strong></dt>
<dd><code class="docutils literal notranslate"><span class="pre">jvm.memory.pools.&lt;memory_pool&gt;.&lt;MetricName&gt;</span></code></dd>
<dt><strong>JMX MBean</strong></dt>
<dd><code class="docutils literal notranslate"><span class="pre">java.lang:type=MemoryPool</span> <span class="pre">name=&lt;memory_pool&gt;</span></code></dd>
</dl>
<table border="1" class="docutils">
<colgroup>
<col width="23%" />
<col width="13%" />
<col width="64%" />
</colgroup>
<tbody valign="top">
<tr class="row-odd"><td>Committed</td>
<td>Gauge&lt;Long&gt;</td>
<td>Amount of memory in bytes that is committed for the JVM to use</td>
</tr>
<tr class="row-even"><td>Init</td>
<td>Gauge&lt;Long&gt;</td>
<td>Amount of memory in bytes that the JVM initially requests from the OS</td>
</tr>
<tr class="row-odd"><td>Max</td>
<td>Gauge&lt;Long&gt;</td>
<td>Maximum amount of memory in bytes that can be used for memory management</td>
</tr>
<tr class="row-even"><td>Usage</td>
<td>Ratio</td>
<td>Ratio of used to maximum memory</td>
</tr>
<tr class="row-odd"><td>Used</td>
<td>Gauge&lt;Long&gt;</td>
<td>Amount of used memory in bytes</td>
</tr>
</tbody>
</table>
</div>
</div>
<div class="section" id="jmx">
<h2>JMX<a class="headerlink" href="#jmx" title="Permalink to this headline">¶</a></h2>
<p>Any JMX based client can access metrics from cassandra.</p>
<p>If you wish to access JMX metrics over http it’s possible to download <a class="reference external" href="http://mx4j.sourceforge.net/">Mx4jTool</a> and
place <code class="docutils literal notranslate"><span class="pre">mx4j-tools.jar</span></code> into the classpath.  On startup you will see in the log:</p>
<div class="highlight-none notranslate"><div class="highlight"><pre><span></span>HttpAdaptor version 3.0.2 started on port 8081
</pre></div>
</div>
<p>To choose a different port (8081 is the default) or a different listen address (0.0.0.0 is not the default) edit
<code class="docutils literal notranslate"><span class="pre">conf/cassandra-env.sh</span></code> and uncomment:</p>
<div class="highlight-none notranslate"><div class="highlight"><pre><span></span>#MX4J_ADDRESS=&quot;-Dmx4jaddress=0.0.0.0&quot;

#MX4J_PORT=&quot;-Dmx4jport=8081&quot;
</pre></div>
</div>
</div>
<div class="section" id="metric-reporters">
<h2>Metric Reporters<a class="headerlink" href="#metric-reporters" title="Permalink to this headline">¶</a></h2>
<p>As mentioned at the top of this section on monitoring the Cassandra metrics can be exported to a number of monitoring
system a number of <a class="reference external" href="http://metrics.dropwizard.io/3.1.0/getting-started/#other-reporting">built in</a> and <a class="reference external" href="http://metrics.dropwizard.io/3.1.0/manual/third-party/">third party</a> reporter plugins.</p>
<p>The configuration of these plugins is managed by the <a class="reference external" href="https://github.com/addthis/metrics-reporter-config">metrics reporter config project</a>. There is a sample configuration file located at
<code class="docutils literal notranslate"><span class="pre">conf/metrics-reporter-config-sample.yaml</span></code>.</p>
<p>Once configured, you simply start cassandra with the flag
<code class="docutils literal notranslate"><span class="pre">-Dcassandra.metricsReporterConfigFile=metrics-reporter-config.yaml</span></code>. The specified .yaml file plus any 3rd party
reporter jars must all be in Cassandra’s classpath.</p>
</div>
</div>


          <div class="doc-prev-next-links" role="navigation" aria-label="footer navigation">
            
            <a href="security.html" class="btn btn-default pull-right " role="button" title="Security" accesskey="n">Next <span class="glyphicon glyphicon-circle-arrow-right" aria-hidden="true"></span></a>
            
            
            <a href="bulk_loading.html" class="btn btn-default" role="button" title="Bulk Loading" accesskey="p"><span class="glyphicon glyphicon-circle-arrow-left" aria-hidden="true"></span> Previous</a>
            
          </div>
          
        </div>
      </div>
    </div>
  </div>
</div>