<div id="docs-body">
 <div class="section">
  <div class="titlepage">
   <div>
    <div>
     <h3 class="title">
      <a name="mysql-cluster-ps-tables">
      </a>
      25.6.19 NDB Cluster and the Performance Schema
     </h3>
    </div>
   </div>
  </div>
  <a class="indexterm" name="idm46045087318608">
  </a>
  <a class="indexterm" name="idm46045087317152">
  </a>
  <p>
   NDB provides information in the MySQL Performance Schema about
   <code class="literal">
    ndbcluster
   </code>
   plugin threads and instrumenting for
      transaction batch memory. These features are described in greater
      detail in the sections which follow.
  </p>
  <div class="simplesect">
   <div class="titlepage">
    <div>
     <div class="simple">
      <h4 class="title">
       <a name="mysql-cluster-plugin-threads">
       </a>
       ndbcluster Plugin Threads
      </h4>
     </div>
    </div>
   </div>
   <a class="indexterm" name="idm46045087313184">
   </a>
   <p>
    <code class="literal">
     ndbcluster
    </code>
    plugin threads are visible in the
        Performance Schema
    <a class="link" href="performance-schema-threads-table.html" title="29.12.22.8 The threads Table">
     <code class="literal">
      threads
     </code>
    </a>
    table,
        as shown in the following query:
   </p>
   <div class="copytoclipboard-wrapper">
    <pre class="programlisting language-sql"><div class="docs-select-all right" id="sa57750451"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql&gt;</span> <span class="token keyword">SELECT</span> <span class="token keyword">name</span><span class="token punctuation">,</span> <span class="token keyword">type</span><span class="token punctuation">,</span> thread_id<span class="token punctuation">,</span> thread_os_id
<span class="token prompt">    -&gt;</span> <span class="token keyword">FROM</span> performance_schema<span class="token punctuation">.</span>threads
<span class="token prompt">    -&gt;</span> <span class="token keyword">WHERE</span> <span class="token keyword">name</span> <span class="token operator">LIKE</span> <span class="token string">'%ndbcluster%'</span>\G
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> name                             <span class="token punctuation">|</span> type       <span class="token punctuation">|</span> thread_id <span class="token punctuation">|</span> thread_os_id <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> thread/ndbcluster/ndb_binlog     <span class="token punctuation">|</span> BACKGROUND <span class="token punctuation">|</span>        30 <span class="token punctuation">|</span>        11980 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> thread/ndbcluster/ndb_index_stat <span class="token punctuation">|</span> BACKGROUND <span class="token punctuation">|</span>        31 <span class="token punctuation">|</span>        11981 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> thread/ndbcluster/ndb_metadata   <span class="token punctuation">|</span> BACKGROUND <span class="token punctuation">|</span>        32 <span class="token punctuation">|</span>        11982 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span></code></pre>
   </div>
   <p>
    The
    <code class="literal">
     threads
    </code>
    table shows all three of the
        threads listed here:
   </p>
   <div class="itemizedlist">
    <ul class="itemizedlist" style="list-style-type: disc; ">
     <li class="listitem">
      <p>
       <code class="literal">
        ndb_binlog
       </code>
       : Binary logging thread
      </p>
     </li>
     <li class="listitem">
      <p>
       <code class="literal">
        ndb_index_stat
       </code>
       : Index statistics thread
      </p>
     </li>
     <li class="listitem">
      <p>
       <code class="literal">
        ndb_metadata
       </code>
       : Metadata thread
      </p>
     </li>
    </ul>
   </div>
   <p>
    These threads are also shown by name in the
    <a class="link" href="performance-schema-setup-threads-table.html" title="29.12.2.5 The setup_threads Table">
     <code class="literal">
      setup_threads
     </code>
    </a>
    table.
   </p>
   <p>
    Thread names are shown in the
    <code class="literal">
     name
    </code>
    column of
        the
    <code class="literal">
     threads
    </code>
    and
    <code class="literal">
     setup_threads
    </code>
    tables using the format
    <code class="literal">
     <em class="replaceable">
      <code>
       prefix
      </code>
     </em>
     /
     <em class="replaceable">
      <code>
       plugin_name
      </code>
     </em>
     /
     <em class="replaceable">
      <code>
       thread_name
      </code>
     </em>
    </code>
    .
    <em class="replaceable">
     <code>
      prefix
     </code>
    </em>
    , the object type as determined
        by the
    <a class="link" href="performance-schema.html" title="Chapter 29 MySQL Performance Schema">
     <code class="literal">
      performance_schema
     </code>
    </a>
    engine,
        is
    <code class="literal">
     thread
    </code>
    for plugin threads (see
    <a class="xref" href="performance-schema-instrument-naming.html#performance-schema-thread-instrument-elements" title="Thread Instrument Elements">
     Thread Instrument Elements
    </a>
    ).
        The
    <em class="replaceable">
     <code>
      plugin_name
     </code>
    </em>
    is
    <code class="literal">
     ndbcluster
    </code>
    .
    <em class="replaceable">
     <code>
      thread_name
     </code>
    </em>
    is the standalone name of
        the thread (
    <code class="literal">
     ndb_binlog
    </code>
    ,
    <code class="literal">
     ndb_index_stat
    </code>
    , or
    <code class="literal">
     ndb_metadata
    </code>
    ).
   </p>
   <p>
    Using the thread ID or OS thread ID for a given thread in the
    <code class="literal">
     threads
    </code>
    or
    <code class="literal">
     setup_threads
    </code>
    table, it is possible to obtain considerable information from
        Performance Schema about plugin execution and resource usage.
        This example shows how to obtain the amount of memory allocated
        by the threads created by the
    <code class="literal">
     ndbcluster
    </code>
    plugin from the
    <code class="literal">
     mem_root
    </code>
    arena by joining the
    <code class="literal">
     threads
    </code>
    and
    <a class="link" href="performance-schema-memory-summary-tables.html" title="29.12.20.10 Memory Summary Tables">
     <code class="literal">
      memory_summary_by_thread_by_event_name
     </code>
    </a>
    tables:
   </p>
   <div class="copytoclipboard-wrapper">
    <pre class="programlisting language-sql"><div class="docs-select-all right" id="sa3272820"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql&gt;</span> <span class="token keyword">SELECT</span>
<span class="token prompt">    -&gt;</span>   t<span class="token punctuation">.</span><span class="token keyword">name</span><span class="token punctuation">,</span>
<span class="token prompt">    -&gt;</span>   m<span class="token punctuation">.</span>sum_number_of_bytes_alloc<span class="token punctuation">,</span>
<span class="token prompt">    -&gt;</span>   <span class="token function">IF</span><span class="token punctuation">(</span>m<span class="token punctuation">.</span>sum_number_of_bytes_alloc <span class="token operator">&gt;</span> <span class="token number">0</span><span class="token punctuation">,</span> <span class="token string">"true"</span><span class="token punctuation">,</span> <span class="token string">"false"</span><span class="token punctuation">)</span> <span class="token keyword">AS</span> <span class="token string">'Has allocated memory'</span>
<span class="token prompt">    -&gt;</span> <span class="token keyword">FROM</span> performance_schema<span class="token punctuation">.</span>memory_summary_by_thread_by_event_name m
<span class="token prompt">    -&gt;</span> <span class="token keyword">JOIN</span> performance_schema<span class="token punctuation">.</span>threads t
<span class="token prompt">    -&gt;</span> <span class="token keyword">ON</span> m<span class="token punctuation">.</span>thread_id <span class="token operator">=</span> t<span class="token punctuation">.</span>thread_id
<span class="token prompt">    -&gt;</span> <span class="token keyword">WHERE</span> t<span class="token punctuation">.</span><span class="token keyword">name</span> <span class="token operator">LIKE</span> <span class="token string">'%ndbcluster%'</span>
<span class="token prompt">    -&gt;</span>   <span class="token operator">AND</span> event_name <span class="token operator">LIKE</span> <span class="token string">'%THD::main_mem_root%'</span><span class="token punctuation">;</span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> name                             <span class="token punctuation">|</span> sum_number_of_bytes_alloc <span class="token punctuation">|</span> Has allocated memory <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> thread/ndbcluster/ndb_binlog     <span class="token punctuation">|</span>                     20576 <span class="token punctuation">|</span> true                 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> thread/ndbcluster/ndb_index_stat <span class="token punctuation">|</span>                         0 <span class="token punctuation">|</span> false                <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> thread/ndbcluster/ndb_metadata   <span class="token punctuation">|</span>                      8240 <span class="token punctuation">|</span> true                 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span></code></pre>
   </div>
  </div>
  <div class="simplesect">
   <div class="titlepage">
    <div>
     <div class="simple">
      <h4 class="title">
       <a name="mysql-cluster-trx-batch-memory">
       </a>
       Transaction Memory Usage
      </h4>
     </div>
    </div>
   </div>
   <a class="indexterm" name="idm46045087270560">
   </a>
   <p>
    You can see the amount of memory used for transaction batching
        by querying the Performance Schema
    <a class="link" href="performance-schema-memory-summary-tables.html" title="29.12.20.10 Memory Summary Tables">
     <code class="literal">
      memory_summary_by_thread_by_event_name
     </code>
    </a>
    table, similar to what is shown here:
   </p>
   <div class="copytoclipboard-wrapper">
    <pre class="programlisting language-sql"><div class="docs-select-all right" id="sa38793028"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql&gt;</span> <span class="token keyword">SELECT</span> EVENT_NAME
<span class="token prompt">    -&gt;</span>   <span class="token keyword">FROM</span> performance_schema<span class="token punctuation">.</span>memory_summary_by_thread_by_event_name
<span class="token prompt">    -&gt;</span>   <span class="token keyword">WHERE</span> THREAD_ID <span class="token operator">=</span> PS_CURRENT_THREAD_ID<span class="token punctuation">(</span><span class="token punctuation">)</span>
<span class="token prompt">    -&gt;</span>     <span class="token operator">AND</span> EVENT_NAME <span class="token operator">LIKE</span> <span class="token string">'memory/ndbcluster/%'</span><span class="token punctuation">;</span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> EVENT_NAME                                <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output"><span class="token punctuation">|</span> memory/ndbcluster/Thd_ndb::batch_mem_root <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">+</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">-</span><span class="token punctuation">+</span></span>
<span class="token output">1 row in set (0.01 sec)</span></code></pre>
   </div>
   <p>
    The
    <code class="literal">
     ndbcluster
    </code>
    transaction memory instrument
        is also visible in the Performance Schema
    <a class="link" href="performance-schema-setup-instruments-table.html" title="29.12.2.3 The setup_instruments Table">
     <code class="literal">
      setup_instruments
     </code>
    </a>
    table, as shown
        here:
   </p>
   <div class="copytoclipboard-wrapper">
    <pre class="programlisting language-sql"><div class="docs-select-all right" id="sa79911348"><div class="copy-help left">Press ⌘+C to copy</div> <div class="right"><button class="clipboard-btn" title="Copy to Clipboard"><span class="icon-clipboard"></span></button></div></div><code class="language-sql"><span class="token prompt">mysql&gt;</span> <span class="token keyword">SELECT</span> <span class="token operator">*</span> <span class="token keyword">from</span> performance_schema<span class="token punctuation">.</span>setup_instruments
<span class="token prompt">    -&gt;</span>   <span class="token keyword">WHERE</span> <span class="token keyword">NAME</span> <span class="token operator">LIKE</span> <span class="token string">'%ndb%'</span>\G
<span class="token output"><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span> 1. row <span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span><span class="token punctuation">*</span>
         NAME<span class="token punctuation">:</span> memory/ndbcluster/Thd_ndb<span class="token punctuation">:</span><span class="token punctuation">:</span>batch_mem_root
      ENABLED<span class="token punctuation">:</span> YES
        TIMED<span class="token punctuation">:</span> NULL
   PROPERTIES<span class="token punctuation">:</span>
   VOLATILITY<span class="token punctuation">:</span> 0
DOCUMENTATION<span class="token punctuation">:</span> Memory used for transaction batching
</span><span class="token output">1 row in set (0.01 sec)</span></code></pre>
   </div>
  </div>
 </div>
 <br/>
</div>
