<div id="docs-body">
 <div class="section">
  <div class="titlepage">
   <div>
    <div>
     <h4 class="title">
      <a name="mysql-cluster-mgm-definition">
      </a>
      25.4.3.5 Defining an NDB Cluster Management Server
     </h4>
    </div>
   </div>
  </div>
  <a class="indexterm" name="idm46045120466752">
  </a>
  <a class="indexterm" name="idm46045120465264">
  </a>
  <p>
   The
   <code class="literal">
    [ndb_mgmd]
   </code>
   section is used to configure
        the behavior of the management server. If multiple management
        servers are employed, you can specify parameters common to all
        of them in an
   <code class="literal">
    [ndb_mgmd default]
   </code>
   section.
   <code class="literal">
    [mgm]
   </code>
   and
   <code class="literal">
    [mgm default]
   </code>
   are older aliases for these, supported for backward
        compatibility.
  </p>
  <p>
   All parameters in the following list are optional and assume
        their default values if omitted.
  </p>
  <div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
   <div class="admon-title">
    Note
   </div>
   <p>
    If neither the
    <code class="literal">
     ExecuteOnComputer
    </code>
    nor the
    <code class="literal">
     HostName
    </code>
    parameter is present, the default
          value
    <code class="literal">
     localhost
    </code>
    is assumed for both.
   </p>
  </div>
  <div class="itemizedlist">
   <ul class="itemizedlist" style="list-style-type: disc; ">
    <li class="listitem">
     <p>
      <a name="ndbparam-mgmd-id">
      </a>
      <code class="literal">
       Id
      </code>
     </p>
     <a class="indexterm" name="idm46045120454816">
     </a>
     <div class="informaltable">
      <a name="id-mgmd-table">
      </a>
      <table frame="box" rules="all" summary="Id management node configuration parameter type and value information" width="35%">
       <colgroup>
        <col style="width: 50%"/>
        <col style="width: 50%"/>
       </colgroup>
       <tbody>
        <tr>
         <th>
          Version (or later)
         </th>
         <td>
          NDB 8.4.0
         </td>
        </tr>
        <tr>
         <th>
          Type or units
         </th>
         <td>
          unsigned
         </td>
        </tr>
        <tr>
         <th>
          Default
         </th>
         <td>
          [...]
         </td>
        </tr>
        <tr>
         <th>
          Range
         </th>
         <td>
          1 - 255
         </td>
        </tr>
        <tr>
         <th>
          Restart Type
         </th>
         <td>
          <p>
           <span class="bold">
            <strong>
             Initial System Restart:
            </strong>
           </span>
           Requires a complete shutdown of the
                    cluster, wiping and restoring the cluster file
                    system from a
           <a class="link" href="mysql-cluster-backup.html" title="25.6.8 Online Backup of NDB Cluster">
            backup
           </a>
           ,
                    and then restarting the cluster. (NDB 8.4.0)
          </p>
         </td>
        </tr>
       </tbody>
      </table>
     </div>
     <p>
      Each node in the cluster has a unique identity. For a
            management node, this is represented by an integer value in
            the range 1 to 255, inclusive. This ID is used by all
            internal cluster messages for addressing the node, and so
            must be unique for each NDB Cluster node, regardless of the
            type of node.
     </p>
     <div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
      <div class="admon-title">
       Note
      </div>
      <p>
       Data node IDs must be less than 145. If you plan to deploy
              a large number of data nodes, it is a good idea to limit
              the node IDs for management nodes (and API nodes) to
              values greater than 144.
      </p>
     </div>
     <p>
      The use of the
      <code class="literal">
       Id
      </code>
      parameter for
            identifying management nodes is deprecated in favor of
      <a class="link" href="mysql-cluster-mgm-definition.html#ndbparam-mgmd-nodeid">
       <code class="literal">
        NodeId
       </code>
      </a>
      . Although
      <code class="literal">
       Id
      </code>
      continues to be supported for backward
            compatibility, it now generates a warning and is subject to
            removal in a future version of NDB Cluster.
     </p>
    </li>
    <li class="listitem">
     <p>
      <a name="ndbparam-mgmd-nodeid">
      </a>
      <code class="literal">
       NodeId
      </code>
     </p>
     <a class="indexterm" name="idm46045120430256">
     </a>
     <div class="informaltable">
      <a name="nodeid-mgmd-table">
      </a>
      <table frame="box" rules="all" summary="NodeId management node configuration parameter type and value information" width="35%">
       <colgroup>
        <col style="width: 50%"/>
        <col style="width: 50%"/>
       </colgroup>
       <tbody>
        <tr>
         <th>
          Version (or later)
         </th>
         <td>
          NDB 8.4.0
         </td>
        </tr>
        <tr>
         <th>
          Type or units
         </th>
         <td>
          unsigned
         </td>
        </tr>
        <tr>
         <th>
          Default
         </th>
         <td>
          [...]
         </td>
        </tr>
        <tr>
         <th>
          Range
         </th>
         <td>
          1 - 255
         </td>
        </tr>
        <tr>
         <th>
          Restart Type
         </th>
         <td>
          <p>
           <span class="bold">
            <strong>
             Initial System Restart:
            </strong>
           </span>
           Requires a complete shutdown of the
                    cluster, wiping and restoring the cluster file
                    system from a
           <a class="link" href="mysql-cluster-backup.html" title="25.6.8 Online Backup of NDB Cluster">
            backup
           </a>
           ,
                    and then restarting the cluster. (NDB 8.4.0)
          </p>
         </td>
        </tr>
       </tbody>
      </table>
     </div>
     <p>
      Each node in the cluster has a unique identity. For a
            management node, this is represented by an integer value in
            the range 1 to 255 inclusive. This ID is used by all
            internal cluster messages for addressing the node, and so
            must be unique for each NDB Cluster node, regardless of the
            type of node.
     </p>
     <div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
      <div class="admon-title">
       Note
      </div>
      <p>
       Data node IDs must be less than 145. If you plan to deploy
              a large number of data nodes, it is a good idea to limit
              the node IDs for management nodes (and API nodes) to
              values greater than 144.
      </p>
     </div>
     <p>
      <code class="literal">
       NodeId
      </code>
      is the preferred parameter name to
            use when identifying management nodes. Although the older
      <a class="link" href="mysql-cluster-mgm-definition.html#ndbparam-mgmd-id">
       <code class="literal">
        Id
       </code>
      </a>
      continues to be
            supported for backward compatibility, it is now deprecated
            and generates a warning when used; it is also subject to
            removal in a future NDB Cluster release.
     </p>
    </li>
    <li class="listitem">
     <p>
      <a name="ndbparam-mgmd-executeoncomputer">
      </a>
      <code class="literal">
       ExecuteOnComputer
      </code>
     </p>
     <a class="indexterm" name="idm46045120406240">
     </a>
     <div class="informaltable">
      <a name="executeoncomputer-mgmd-table">
      </a>
      <table frame="box" rules="all" summary="ExecuteOnComputer management node configuration parameter type and value information" width="35%">
       <colgroup>
        <col style="width: 50%"/>
        <col style="width: 50%"/>
       </colgroup>
       <tbody>
        <tr>
         <th>
          Version (or later)
         </th>
         <td>
          NDB 8.4.0
         </td>
        </tr>
        <tr>
         <th>
          Type or units
         </th>
         <td>
          name
         </td>
        </tr>
        <tr>
         <th>
          Default
         </th>
         <td>
          [...]
         </td>
        </tr>
        <tr>
         <th>
          Range
         </th>
         <td>
          ...
         </td>
        </tr>
        <tr>
         <th>
          Deprecated
         </th>
         <td>
          Yes (in NDB 7.5)
         </td>
        </tr>
        <tr>
         <th>
          Restart Type
         </th>
         <td>
          <p>
           <span class="bold">
            <strong>
             System Restart:
            </strong>
           </span>
           Requires a complete shutdown and restart
                    of the cluster. (NDB 8.4.0)
          </p>
         </td>
        </tr>
       </tbody>
      </table>
     </div>
     <p>
      This refers to the
      <code class="literal">
       Id
      </code>
      set for one of the
            computers defined in a
      <code class="literal">
       [computer]
      </code>
      section
            of the
      <code class="filename">
       config.ini
      </code>
      file.
     </p>
     <div class="important" style="margin-left: 0.5in; margin-right: 0.5in;">
      <div class="admon-title">
       Important
      </div>
      <p>
       This parameter is deprecated, and is subject to removal in
              a future release. Use the
       <a class="link" href="mysql-cluster-mgm-definition.html#ndbparam-mgmd-hostname">
        <code class="literal">
         HostName
        </code>
       </a>
       parameter
              instead.
      </p>
     </div>
    </li>
    <li class="listitem">
     <p>
      <a name="ndbparam-mgmd-portnumber">
      </a>
      <code class="literal">
       PortNumber
      </code>
     </p>
     <a class="indexterm" name="idm46045120380768">
     </a>
     <div class="informaltable">
      <a name="portnumber-mgmd-table">
      </a>
      <table frame="box" rules="all" summary="PortNumber management node configuration parameter type and value information" width="35%">
       <colgroup>
        <col style="width: 50%"/>
        <col style="width: 50%"/>
       </colgroup>
       <tbody>
        <tr>
         <th>
          Version (or later)
         </th>
         <td>
          NDB 8.4.0
         </td>
        </tr>
        <tr>
         <th>
          Type or units
         </th>
         <td>
          unsigned
         </td>
        </tr>
        <tr>
         <th>
          Default
         </th>
         <td>
          1186
         </td>
        </tr>
        <tr>
         <th>
          Range
         </th>
         <td>
          0 - 64K
         </td>
        </tr>
        <tr>
         <th>
          Restart Type
         </th>
         <td>
          <p>
           <span class="bold">
            <strong>
             System Restart:
            </strong>
           </span>
           Requires a complete shutdown and restart
                    of the cluster. (NDB 8.4.0)
          </p>
         </td>
        </tr>
       </tbody>
      </table>
     </div>
     <p>
      This is the port number on which the management server
            listens for configuration requests and management commands.
     </p>
    </li>
    <li class="listitem">
     <a name="ndbparam-mgmd-dedicated">
     </a>
     <a class="indexterm" name="idm46045120362720">
     </a>
     <p>
     </p>
     <p>
      The node ID for this node can be given out only to
            connections that explicitly request it. A management server
            that requests
      <span class="quote">
       “
       <span class="quote">
        any
       </span>
       ”
      </span>
      node ID cannot use this
            one. This parameter can be used when running multiple
            management servers on the same host, and
      <a class="link" href="mysql-cluster-mgm-definition.html#ndbparam-mgmd-hostname">
       <code class="literal">
        HostName
       </code>
      </a>
      is not
            sufficient for distinguishing among processes.
     </p>
    </li>
    <li class="listitem">
     <p>
      <a name="ndbparam-mgmd-hostname">
      </a>
      <code class="literal">
       HostName
      </code>
     </p>
     <a class="indexterm" name="idm46045120356496">
     </a>
     <div class="informaltable">
      <a name="hostname-mgmd-table">
      </a>
      <table frame="box" rules="all" summary="HostName management node configuration parameter type and value information" width="35%">
       <colgroup>
        <col style="width: 50%"/>
        <col style="width: 50%"/>
       </colgroup>
       <tbody>
        <tr>
         <th>
          Version (or later)
         </th>
         <td>
          NDB 8.4.0
         </td>
        </tr>
        <tr>
         <th>
          Type or units
         </th>
         <td>
          name or IP address
         </td>
        </tr>
        <tr>
         <th>
          Default
         </th>
         <td>
          [...]
         </td>
        </tr>
        <tr>
         <th>
          Range
         </th>
         <td>
          ...
         </td>
        </tr>
        <tr>
         <th>
          Restart Type
         </th>
         <td>
          <p>
           <span class="bold">
            <strong>
             Node Restart:
            </strong>
           </span>
           Requires a
           <a class="link" href="mysql-cluster-rolling-restart.html" title="25.6.5 Performing a Rolling Restart of an NDB Cluster">
            rolling
                    restart
           </a>
           of the cluster. (NDB 8.4.0)
          </p>
         </td>
        </tr>
       </tbody>
      </table>
     </div>
     <p>
      Specifying this parameter defines the hostname of the
            computer on which the management node is to reside. Use
      <code class="literal">
       HostName
      </code>
      to specify a host name other
            than
      <code class="literal">
       localhost
      </code>
      .
     </p>
    </li>
    <li class="listitem">
     <p>
      <a name="ndbparam-mgmd-locationdomainid">
      </a>
      <a class="link" href="mysql-cluster-mgm-definition.html#ndbparam-mgmd-locationdomainid">
       <code class="literal">
        LocationDomainId
       </code>
      </a>
     </p>
     <a class="indexterm" name="idm46045120334512">
     </a>
     <div class="informaltable">
      <a name="locationdomainid-mgmd-table">
      </a>
      <table frame="box" rules="all" summary="LocationDomainId management node configuration parameter type and value information" width="35%">
       <colgroup>
        <col style="width: 50%"/>
        <col style="width: 50%"/>
       </colgroup>
       <tbody>
        <tr>
         <th>
          Version (or later)
         </th>
         <td>
          NDB 8.4.0
         </td>
        </tr>
        <tr>
         <th>
          Type or units
         </th>
         <td>
          integer
         </td>
        </tr>
        <tr>
         <th>
          Default
         </th>
         <td>
          0
         </td>
        </tr>
        <tr>
         <th>
          Range
         </th>
         <td>
          0 - 16
         </td>
        </tr>
        <tr>
         <th>
          Restart Type
         </th>
         <td>
          <p>
           <span class="bold">
            <strong>
             System Restart:
            </strong>
           </span>
           Requires a complete shutdown and restart
                    of the cluster. (NDB 8.4.0)
          </p>
         </td>
        </tr>
       </tbody>
      </table>
     </div>
     <p>
      Assigns a management node to a specific
      <a class="ulink" href="https://docs.us-phoenix-1.oraclecloud.com/Content/General/Concepts/regions.htm" target="_blank">
       availability
            domain
      </a>
      (also known as an availability zone) within a
            cloud. By informing
      <code class="literal">
       NDB
      </code>
      which nodes are
            in which availability domains, performance can be improved
            in a cloud environment in the following ways:
     </p>
     <div class="itemizedlist">
      <ul class="itemizedlist" style="list-style-type: circle; ">
       <li class="listitem">
        <p>
         If requested data is not found on the same node, reads
                can be directed to another node in the same availability
                domain.
        </p>
       </li>
       <li class="listitem">
        <p>
         Communication between nodes in different availability
                domains are guaranteed to use
         <code class="literal">
          NDB
         </code>
         transporters' WAN support without any further
                manual intervention.
        </p>
       </li>
       <li class="listitem">
        <p>
         The transporter's group number can be based on
                which availability domain is used, such that also SQL
                and other API nodes communicate with local data nodes in
                the same availability domain whenever possible.
        </p>
       </li>
       <li class="listitem">
        <p>
         The arbitrator can be selected from an availability
                domain in which no data nodes are present, or, if no
                such availability domain can be found, from a third
                availability domain.
        </p>
       </li>
      </ul>
     </div>
     <p>
      <code class="literal">
       LocationDomainId
      </code>
      takes an integer value
            between 0 and 16 inclusive, with 0 being the default; using
            0 is the same as leaving the parameter unset.
     </p>
    </li>
    <li class="listitem">
     <p>
      <a name="ndbparam-mgmd-logdestination">
      </a>
      <a class="link" href="mysql-cluster-mgm-definition.html#ndbparam-mgmd-logdestination">
       <code class="literal">
        LogDestination
       </code>
      </a>
     </p>
     <a class="indexterm" name="idm46045120306896">
     </a>
     <div class="informaltable">
      <a name="logdestination-mgmd-table">
      </a>
      <table frame="box" rules="all" summary="LogDestination management node configuration parameter type and value information" width="35%">
       <colgroup>
        <col style="width: 50%"/>
        <col style="width: 50%"/>
       </colgroup>
       <tbody>
        <tr>
         <th>
          Version (or later)
         </th>
         <td>
          NDB 8.4.0
         </td>
        </tr>
        <tr>
         <th>
          Type or units
         </th>
         <td>
          {CONSOLE|SYSLOG|FILE}
         </td>
        </tr>
        <tr>
         <th>
          Default
         </th>
         <td>
          FILE: filename=ndb_nodeid_cluster.log, maxsize=1000000, maxfiles=6
         </td>
        </tr>
        <tr>
         <th>
          Range
         </th>
         <td>
          ...
         </td>
        </tr>
        <tr>
         <th>
          Restart Type
         </th>
         <td>
          <p>
           <span class="bold">
            <strong>
             Node Restart:
            </strong>
           </span>
           Requires a
           <a class="link" href="mysql-cluster-rolling-restart.html" title="25.6.5 Performing a Rolling Restart of an NDB Cluster">
            rolling
                    restart
           </a>
           of the cluster. (NDB 8.4.0)
          </p>
         </td>
        </tr>
       </tbody>
      </table>
     </div>
     <p>
      This parameter specifies where to send cluster logging
            information. There are three options in this
            regard—
      <code class="literal">
       CONSOLE
      </code>
      ,
      <code class="literal">
       SYSLOG
      </code>
      , and
      <code class="literal">
       FILE
      </code>
      —with
      <code class="literal">
       FILE
      </code>
      being the default:
     </p>
     <div class="itemizedlist">
      <ul class="itemizedlist" style="list-style-type: circle; ">
       <li class="listitem">
        <p>
         <code class="literal">
          CONSOLE
         </code>
         outputs the log to
         <code class="literal">
          stdout
         </code>
         :
        </p>
        <div class="copytoclipboard-wrapper">
         <pre class="programlisting one-line language-simple"><div class="docs-select-all right" id="sa53493963"><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-simple">CONSOLE</code></pre>
        </div>
       </li>
       <li class="listitem">
        <p>
         <code class="literal">
          SYSLOG
         </code>
         sends the log to a
         <code class="literal">
          syslog
         </code>
         facility, possible values
                being one of
         <code class="literal">
          auth
         </code>
         ,
         <code class="literal">
          authpriv
         </code>
         ,
         <code class="literal">
          cron
         </code>
         ,
         <code class="literal">
          daemon
         </code>
         ,
         <code class="literal">
          ftp
         </code>
         ,
         <code class="literal">
          kern
         </code>
         ,
         <code class="literal">
          lpr
         </code>
         ,
         <code class="literal">
          mail
         </code>
         ,
         <code class="literal">
          news
         </code>
         ,
         <code class="literal">
          syslog
         </code>
         ,
         <code class="literal">
          user
         </code>
         ,
         <code class="literal">
          uucp
         </code>
         ,
         <code class="literal">
          local0
         </code>
         ,
         <code class="literal">
          local1
         </code>
         ,
         <code class="literal">
          local2
         </code>
         ,
         <code class="literal">
          local3
         </code>
         ,
         <code class="literal">
          local4
         </code>
         ,
         <code class="literal">
          local5
         </code>
         ,
         <code class="literal">
          local6
         </code>
         , or
         <code class="literal">
          local7
         </code>
         .
        </p>
        <div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
         <div class="admon-title">
          Note
         </div>
         <p>
          Not every facility is necessarily supported by every
                  operating system.
         </p>
        </div>
        <div class="copytoclipboard-wrapper">
         <pre class="programlisting one-line language-simple"><div class="docs-select-all right" id="sa41465471"><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-simple">SYSLOG<span class="token operator">:</span>facility<span class="token operator">=</span>syslog</code></pre>
        </div>
       </li>
       <li class="listitem">
        <p>
         <code class="literal">
          FILE
         </code>
         pipes the cluster log output to
                a regular file on the same machine. The following values
                can be specified:
        </p>
        <div class="itemizedlist">
         <ul class="itemizedlist" style="list-style-type: square; ">
          <li class="listitem">
           <p>
            <code class="literal">
             filename
            </code>
            : The name of the log
                    file.
           </p>
           <p>
            The default log file name used in such cases is
            <code class="filename">
             ndb_
             <em class="replaceable">
              <code>
               nodeid
              </code>
             </em>
             _cluster.log
            </code>
            .
           </p>
          </li>
          <li class="listitem">
           <p>
            <code class="literal">
             maxsize
            </code>
            : The maximum size (in
                    bytes) to which the file can grow before logging
                    rolls over to a new file. When this occurs, the old
                    log file is renamed by appending
            <em class="replaceable">
             <code>
              .N
             </code>
            </em>
            to the file name,
                    where
            <em class="replaceable">
             <code>
              N
             </code>
            </em>
            is the next
                    number not yet used with this name.
           </p>
          </li>
          <li class="listitem">
           <p>
            <code class="literal">
             maxfiles
            </code>
            : The maximum number of
                    log files.
           </p>
          </li>
         </ul>
        </div>
        <div class="copytoclipboard-wrapper">
         <pre class="programlisting one-line language-simple"><div class="docs-select-all right" id="sa30304262"><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-simple">FILE<span class="token operator">:</span>filename<span class="token operator">=</span>cluster<span class="token punctuation">.</span>log<span class="token punctuation">,</span>maxsize<span class="token operator">=</span>1000000<span class="token punctuation">,</span>maxfiles<span class="token operator">=</span>6</code></pre>
        </div>
        <p>
         The default value for the
         <code class="literal">
          FILE
         </code>
         parameter is
         <code class="literal">
          FILE:filename=ndb_
          <em class="replaceable">
           <code>
            node_id
           </code>
          </em>
          _cluster.log,maxsize=1000000,maxfiles=6
         </code>
         ,
                where
         <em class="replaceable">
          <code>
           node_id
          </code>
         </em>
         is the ID of
                the node.
        </p>
       </li>
      </ul>
     </div>
     <p>
      It is possible to specify multiple log destinations
            separated by semicolons as shown here:
     </p>
     <div class="copytoclipboard-wrapper">
      <pre class="programlisting one-line language-simple"><div class="docs-select-all right" id="sa89445517"><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-simple">CONSOLE<span class="token punctuation">;</span>SYSLOG<span class="token operator">:</span>facility<span class="token operator">=</span>local0<span class="token punctuation">;</span>FILE<span class="token operator">:</span>filename<span class="token operator">=</span><span class="token operator">/</span>var<span class="token operator">/</span>log<span class="token operator">/</span>mgmd</code></pre>
     </div>
    </li>
    <li class="listitem">
     <p>
      <a name="ndbparam-mgmd-arbitrationrank">
      </a>
      <code class="literal">
       ArbitrationRank
      </code>
     </p>
     <a class="indexterm" name="idm46045120247232">
     </a>
     <div class="informaltable">
      <a name="arbitrationrank-mgmd-table">
      </a>
      <table frame="box" rules="all" summary="ArbitrationRank management node configuration parameter type and value information" width="35%">
       <colgroup>
        <col style="width: 50%"/>
        <col style="width: 50%"/>
       </colgroup>
       <tbody>
        <tr>
         <th>
          Version (or later)
         </th>
         <td>
          NDB 8.4.0
         </td>
        </tr>
        <tr>
         <th>
          Type or units
         </th>
         <td>
          0-2
         </td>
        </tr>
        <tr>
         <th>
          Default
         </th>
         <td>
          1
         </td>
        </tr>
        <tr>
         <th>
          Range
         </th>
         <td>
          0 - 2
         </td>
        </tr>
        <tr>
         <th>
          Restart Type
         </th>
         <td>
          <p>
           <span class="bold">
            <strong>
             Node Restart:
            </strong>
           </span>
           Requires a
           <a class="link" href="mysql-cluster-rolling-restart.html" title="25.6.5 Performing a Rolling Restart of an NDB Cluster">
            rolling
                    restart
           </a>
           of the cluster. (NDB 8.4.0)
          </p>
         </td>
        </tr>
       </tbody>
      </table>
     </div>
     <p>
      This parameter is used to define which nodes can act as
            arbitrators. Only management nodes and SQL nodes can be
            arbitrators.
      <code class="literal">
       ArbitrationRank
      </code>
      can take one
            of the following values:
     </p>
     <div class="itemizedlist">
      <ul class="itemizedlist" style="list-style-type: circle; ">
       <li class="listitem">
        <p>
         <code class="literal">
          0
         </code>
         : The node is never used as an
                arbitrator.
        </p>
       </li>
       <li class="listitem">
        <p>
         <code class="literal">
          1
         </code>
         : The node has high priority; that
                is, it is preferred as an arbitrator over low-priority
                nodes.
        </p>
       </li>
       <li class="listitem">
        <p>
         <code class="literal">
          2
         </code>
         : Indicates a low-priority node
                which is used as an arbitrator only if a node with a
                higher priority is not available for that purpose.
        </p>
       </li>
      </ul>
     </div>
     <p>
      Normally, the management server should be configured as an
            arbitrator by setting its
      <code class="literal">
       ArbitrationRank
      </code>
      to 1 (the default for management nodes) and those for all
            SQL nodes to 0 (the default for SQL nodes).
     </p>
     <p>
      You can disable arbitration completely either by setting
      <code class="literal">
       ArbitrationRank
      </code>
      to 0 on all management
            and SQL nodes, or by setting the
      <a class="link" href="mysql-cluster-ndbd-definition.html#ndbparam-ndbd-arbitration">
       <code class="literal">
        Arbitration
       </code>
      </a>
      parameter in the
      <code class="literal">
       [ndbd default]
      </code>
      section
            of the
      <code class="filename">
       config.ini
      </code>
      global configuration
            file. Setting
      <a class="link" href="mysql-cluster-ndbd-definition.html#ndbparam-ndbd-arbitration">
       <code class="literal">
        Arbitration
       </code>
      </a>
      causes
            any settings for
      <code class="literal">
       ArbitrationRank
      </code>
      to be
            disregarded.
     </p>
    </li>
    <li class="listitem">
     <p>
      <a name="ndbparam-mgmd-arbitrationdelay">
      </a>
      <code class="literal">
       ArbitrationDelay
      </code>
     </p>
     <a class="indexterm" name="idm46045120214000">
     </a>
     <div class="informaltable">
      <a name="arbitrationdelay-mgmd-table">
      </a>
      <table frame="box" rules="all" summary="ArbitrationDelay management node configuration parameter type and value information" width="35%">
       <colgroup>
        <col style="width: 50%"/>
        <col style="width: 50%"/>
       </colgroup>
       <tbody>
        <tr>
         <th>
          Version (or later)
         </th>
         <td>
          NDB 8.4.0
         </td>
        </tr>
        <tr>
         <th>
          Type or units
         </th>
         <td>
          milliseconds
         </td>
        </tr>
        <tr>
         <th>
          Default
         </th>
         <td>
          0
         </td>
        </tr>
        <tr>
         <th>
          Range
         </th>
         <td>
          0 - 4294967039 (0xFFFFFEFF)
         </td>
        </tr>
        <tr>
         <th>
          Restart Type
         </th>
         <td>
          <p>
           <span class="bold">
            <strong>
             Node Restart:
            </strong>
           </span>
           Requires a
           <a class="link" href="mysql-cluster-rolling-restart.html" title="25.6.5 Performing a Rolling Restart of an NDB Cluster">
            rolling
                    restart
           </a>
           of the cluster. (NDB 8.4.0)
          </p>
         </td>
        </tr>
       </tbody>
      </table>
     </div>
     <p>
      An integer value which causes the management server's
            responses to arbitration requests to be delayed by that
            number of milliseconds. By default, this value is 0; it is
            normally not necessary to change it.
     </p>
    </li>
    <li class="listitem">
     <p>
      <a name="ndbparam-mgmd-datadir">
      </a>
      <code class="literal">
       DataDir
      </code>
     </p>
     <a class="indexterm" name="idm46045120193984">
     </a>
     <div class="informaltable">
      <a name="datadir-mgmd-table">
      </a>
      <table frame="box" rules="all" summary="DataDir management node configuration parameter type and value information" width="35%">
       <colgroup>
        <col style="width: 50%"/>
        <col style="width: 50%"/>
       </colgroup>
       <tbody>
        <tr>
         <th>
          Version (or later)
         </th>
         <td>
          NDB 8.4.0
         </td>
        </tr>
        <tr>
         <th>
          Type or units
         </th>
         <td>
          path
         </td>
        </tr>
        <tr>
         <th>
          Default
         </th>
         <td>
          .
         </td>
        </tr>
        <tr>
         <th>
          Range
         </th>
         <td>
          ...
         </td>
        </tr>
        <tr>
         <th>
          Restart Type
         </th>
         <td>
          <p>
           <span class="bold">
            <strong>
             Node Restart:
            </strong>
           </span>
           Requires a
           <a class="link" href="mysql-cluster-rolling-restart.html" title="25.6.5 Performing a Rolling Restart of an NDB Cluster">
            rolling
                    restart
           </a>
           of the cluster. (NDB 8.4.0)
          </p>
         </td>
        </tr>
       </tbody>
      </table>
     </div>
     <p>
      This specifies the directory where output files from the
            management server are placed. These files include cluster
            log files, process output files, and the daemon's
            process ID (PID) file. (For log files, this location can be
            overridden by setting the
      <code class="literal">
       FILE
      </code>
      parameter
            for
      <a class="link" href="mysql-cluster-mgm-definition.html#ndbparam-mgmd-logdestination">
       <code class="literal">
        LogDestination
       </code>
      </a>
      ,
            as discussed previously in this section.)
     </p>
     <p>
      The default value for this parameter is the directory in
            which
      <a class="link" href="mysql-cluster-programs-ndb-mgmd.html" title="25.5.4 ndb_mgmd — The NDB Cluster Management Server Daemon">
       <span class="command">
        <strong>
         ndb_mgmd
        </strong>
       </span>
      </a>
      is located.
     </p>
    </li>
    <li class="listitem">
     <p>
      <a name="ndbparam-mgmd-portnumberstats">
      </a>
      <code class="literal">
       PortNumberStats
      </code>
     </p>
     <a class="indexterm" name="idm46045120170064">
     </a>
     <div class="informaltable">
      <a name="portnumberstats-mgmd-table">
      </a>
      <table frame="box" rules="all" summary="PortNumberStats management node configuration parameter type and value information" width="35%">
       <colgroup>
        <col style="width: 50%"/>
        <col style="width: 50%"/>
       </colgroup>
       <tbody>
        <tr>
         <th>
          Version (or later)
         </th>
         <td>
          NDB 8.4.0
         </td>
        </tr>
        <tr>
         <th>
          Type or units
         </th>
         <td>
          unsigned
         </td>
        </tr>
        <tr>
         <th>
          Default
         </th>
         <td>
          [...]
         </td>
        </tr>
        <tr>
         <th>
          Range
         </th>
         <td>
          0 - 64K
         </td>
        </tr>
        <tr>
         <th>
          Restart Type
         </th>
         <td>
          <p>
           <span class="bold">
            <strong>
             Node Restart:
            </strong>
           </span>
           Requires a
           <a class="link" href="mysql-cluster-rolling-restart.html" title="25.6.5 Performing a Rolling Restart of an NDB Cluster">
            rolling
                    restart
           </a>
           of the cluster. (NDB 8.4.0)
          </p>
         </td>
        </tr>
       </tbody>
      </table>
     </div>
     <p>
      This parameter specifies the port number used to obtain
            statistical information from an NDB Cluster management
            server. It has no default value.
     </p>
    </li>
    <li class="listitem">
     <p>
      <a name="ndbparam-mgmd-wan">
      </a>
      <a class="link" href="mysql-cluster-mgm-definition.html#ndbparam-mgmd-wan">
       <code class="literal">
        Wan
       </code>
      </a>
     </p>
     <a class="indexterm" name="idm46045120149520">
     </a>
     <div class="informaltable">
      <a name="wan-mgmd-table">
      </a>
      <table frame="box" rules="all" summary="wan management node configuration parameter type and value information" width="35%">
       <colgroup>
        <col style="width: 50%"/>
        <col style="width: 50%"/>
       </colgroup>
       <tbody>
        <tr>
         <th>
          Version (or later)
         </th>
         <td>
          NDB 8.4.0
         </td>
        </tr>
        <tr>
         <th>
          Type or units
         </th>
         <td>
          boolean
         </td>
        </tr>
        <tr>
         <th>
          Default
         </th>
         <td>
          false
         </td>
        </tr>
        <tr>
         <th>
          Range
         </th>
         <td>
          true, false
         </td>
        </tr>
        <tr>
         <th>
          Restart Type
         </th>
         <td>
          <p>
           <span class="bold">
            <strong>
             Node Restart:
            </strong>
           </span>
           Requires a
           <a class="link" href="mysql-cluster-rolling-restart.html" title="25.6.5 Performing a Rolling Restart of an NDB Cluster">
            rolling
                    restart
           </a>
           of the cluster. (NDB 8.4.0)
          </p>
         </td>
        </tr>
       </tbody>
      </table>
     </div>
     <p>
      Use WAN TCP setting as default.
     </p>
    </li>
    <li class="listitem">
     <p>
      <a name="ndbparam-mgmd-heartbeatthreadpriority">
      </a>
      <code class="literal">
       HeartbeatThreadPriority
      </code>
     </p>
     <a class="indexterm" name="idm46045120129728">
     </a>
     <div class="informaltable">
      <a name="heartbeatthreadpriority-mgmd-table">
      </a>
      <table frame="box" rules="all" summary="HeartbeatThreadPriority management node configuration parameter type and value information" width="35%">
       <colgroup>
        <col style="width: 50%"/>
        <col style="width: 50%"/>
       </colgroup>
       <tbody>
        <tr>
         <th>
          Version (or later)
         </th>
         <td>
          NDB 8.4.0
         </td>
        </tr>
        <tr>
         <th>
          Type or units
         </th>
         <td>
          string
         </td>
        </tr>
        <tr>
         <th>
          Default
         </th>
         <td>
          [...]
         </td>
        </tr>
        <tr>
         <th>
          Range
         </th>
         <td>
          ...
         </td>
        </tr>
        <tr>
         <th>
          Restart Type
         </th>
         <td>
          <p>
           <span class="bold">
            <strong>
             Node Restart:
            </strong>
           </span>
           Requires a
           <a class="link" href="mysql-cluster-rolling-restart.html" title="25.6.5 Performing a Rolling Restart of an NDB Cluster">
            rolling
                    restart
           </a>
           of the cluster. (NDB 8.4.0)
          </p>
         </td>
        </tr>
       </tbody>
      </table>
     </div>
     <p>
      Set the scheduling policy and priority of heartbeat threads
            for management and API nodes.
     </p>
     <p>
      The syntax for setting this parameter is shown here:
     </p>
     <div class="copytoclipboard-wrapper">
      <pre class="programlisting language-ini"><div class="docs-select-all right" id="sa23080046"><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-ini"><span class="token constant">HeartbeatThreadPriority</span> <span class="token attr-value"><span class="token punctuation">=</span> <em class="replaceable">policy</em>[, <em class="replaceable">priority</em>]</span>

<em class="replaceable">policy</em>:
  {FIFO | RR}</code></pre>
     </div>
     <p>
      When setting this parameter, you must specify a policy. This
            is one of
      <code class="literal">
       FIFO
      </code>
      (first in, first out) or
      <code class="literal">
       RR
      </code>
      (round robin). The policy value is
            followed optionally by the priority (an integer).
     </p>
    </li>
    <li class="listitem">
     <p>
      <a name="ndbparam-mgmd-extrasendbuffermemory">
      </a>
      <code class="literal">
       ExtraSendBufferMemory
      </code>
     </p>
     <a class="indexterm" name="idm46045120105072">
     </a>
     <div class="informaltable">
      <a name="extrasendbuffermemory-mgmd-table">
      </a>
      <table frame="box" rules="all" summary="ExtraSendBufferMemory management node configuration parameter type and value information" width="35%">
       <colgroup>
        <col style="width: 50%"/>
        <col style="width: 50%"/>
       </colgroup>
       <tbody>
        <tr>
         <th>
          Version (or later)
         </th>
         <td>
          NDB 8.4.0
         </td>
        </tr>
        <tr>
         <th>
          Type or units
         </th>
         <td>
          bytes
         </td>
        </tr>
        <tr>
         <th>
          Default
         </th>
         <td>
          0
         </td>
        </tr>
        <tr>
         <th>
          Range
         </th>
         <td>
          0 - 32G
         </td>
        </tr>
        <tr>
         <th>
          Restart Type
         </th>
         <td>
          <p>
           <span class="bold">
            <strong>
             Node Restart:
            </strong>
           </span>
           Requires a
           <a class="link" href="mysql-cluster-rolling-restart.html" title="25.6.5 Performing a Rolling Restart of an NDB Cluster">
            rolling
                    restart
           </a>
           of the cluster. (NDB 8.4.0)
          </p>
         </td>
        </tr>
       </tbody>
      </table>
     </div>
     <p>
      This parameter specifies the amount of transporter send
            buffer memory to allocate in addition to any that has been
            set using
      <a class="link" href="mysql-cluster-mgm-definition.html#ndbparam-mgmd-totalsendbuffermemory">
       <code class="literal">
        TotalSendBufferMemory
       </code>
      </a>
      ,
      <a class="link" href="mysql-cluster-tcp-definition.html#ndbparam-tcp-sendbuffermemory">
       <code class="literal">
        SendBufferMemory
       </code>
      </a>
      , or
            both.
     </p>
    </li>
    <li class="listitem">
     <p>
      <a name="ndbparam-mgmd-requiretls">
      </a>
      <code class="literal">
       RequireTls
      </code>
     </p>
     <a class="indexterm" name="idm46045120082176">
     </a>
     <div class="informaltable">
      <a name="requiretls-mgmd-table">
      </a>
      <table frame="box" rules="all" summary="RequireTls management node configuration parameter type and value information" width="35%">
       <colgroup>
        <col style="width: 50%"/>
        <col style="width: 50%"/>
       </colgroup>
       <tbody>
        <tr>
         <th>
          Version (or later)
         </th>
         <td>
          NDB 8.4.0
         </td>
        </tr>
        <tr>
         <th>
          Type or units
         </th>
         <td>
          boolean
         </td>
        </tr>
        <tr>
         <th>
          Default
         </th>
         <td>
          false
         </td>
        </tr>
        <tr>
         <th>
          Range
         </th>
         <td>
          ...
         </td>
        </tr>
        <tr>
         <th>
          Restart Type
         </th>
         <td>
          <p>
           <span class="bold">
            <strong>
             Node Restart:
            </strong>
           </span>
           Requires a
           <a class="link" href="mysql-cluster-rolling-restart.html" title="25.6.5 Performing a Rolling Restart of an NDB Cluster">
            rolling
                    restart
           </a>
           of the cluster. (NDB 8.4.0)
          </p>
         </td>
        </tr>
       </tbody>
      </table>
     </div>
     <p>
      If this parameter is set to
      <code class="literal">
       true
      </code>
      , a
            client, once connected to this management node, must be
            authenticated using TLS before the connection can be used
            for anything else.
     </p>
    </li>
    <li class="listitem">
     <p>
      <a name="ndbparam-mgmd-totalsendbuffermemory">
      </a>
      <code class="literal">
       TotalSendBufferMemory
      </code>
     </p>
     <a class="indexterm" name="idm46045120061120">
     </a>
     <div class="informaltable">
      <a name="totalsendbuffermemory-mgmd-table">
      </a>
      <table frame="box" rules="all" summary="TotalSendBufferMemory management node configuration parameter type and value information" width="35%">
       <colgroup>
        <col style="width: 50%"/>
        <col style="width: 50%"/>
       </colgroup>
       <tbody>
        <tr>
         <th>
          Version (or later)
         </th>
         <td>
          NDB 8.4.0
         </td>
        </tr>
        <tr>
         <th>
          Type or units
         </th>
         <td>
          bytes
         </td>
        </tr>
        <tr>
         <th>
          Default
         </th>
         <td>
          0
         </td>
        </tr>
        <tr>
         <th>
          Range
         </th>
         <td>
          256K - 4294967039 (0xFFFFFEFF)
         </td>
        </tr>
        <tr>
         <th>
          Restart Type
         </th>
         <td>
          <p>
           <span class="bold">
            <strong>
             Node Restart:
            </strong>
           </span>
           Requires a
           <a class="link" href="mysql-cluster-rolling-restart.html" title="25.6.5 Performing a Rolling Restart of an NDB Cluster">
            rolling
                    restart
           </a>
           of the cluster. (NDB 8.4.0)
          </p>
         </td>
        </tr>
       </tbody>
      </table>
     </div>
     <p>
      This parameter is used to determine the total amount of
            memory to allocate on this node for shared send buffer
            memory among all configured transporters.
     </p>
     <p>
      If this parameter is set, its minimum permitted value is
            256KB; 0 indicates that the parameter has not been set. For
            more detailed information, see
      <a class="xref" href="mysql-cluster-config-send-buffers.html" title="25.4.3.14 Configuring NDB Cluster Send Buffer Parameters">
       Section 25.4.3.14, “Configuring NDB Cluster Send Buffer Parameters”
      </a>
      .
     </p>
    </li>
    <li class="listitem">
     <p>
      <a name="ndbparam-mgmd-heartbeatintervalmgmdmgmd">
      </a>
      <code class="literal">
       HeartbeatIntervalMgmdMgmd
      </code>
     </p>
     <a class="indexterm" name="idm46045120039280">
     </a>
     <div class="informaltable">
      <a name="heartbeatintervalmgmdmgmd-mgmd-table">
      </a>
      <table frame="box" rules="all" summary="HeartbeatIntervalMgmdMgmd management node configuration parameter type and value information" width="35%">
       <colgroup>
        <col style="width: 50%"/>
        <col style="width: 50%"/>
       </colgroup>
       <tbody>
        <tr>
         <th>
          Version (or later)
         </th>
         <td>
          NDB 8.4.0
         </td>
        </tr>
        <tr>
         <th>
          Type or units
         </th>
         <td>
          milliseconds
         </td>
        </tr>
        <tr>
         <th>
          Default
         </th>
         <td>
          1500
         </td>
        </tr>
        <tr>
         <th>
          Range
         </th>
         <td>
          100 - 4294967039 (0xFFFFFEFF)
         </td>
        </tr>
        <tr>
         <th>
          Restart Type
         </th>
         <td>
          <p>
           <span class="bold">
            <strong>
             Node Restart:
            </strong>
           </span>
           Requires a
           <a class="link" href="mysql-cluster-rolling-restart.html" title="25.6.5 Performing a Rolling Restart of an NDB Cluster">
            rolling
                    restart
           </a>
           of the cluster. (NDB 8.4.0)
          </p>
         </td>
        </tr>
       </tbody>
      </table>
     </div>
     <p>
      Specify the interval between heartbeat messages used to
            determine whether another management node is on contact with
            this one. The management node waits after 3 of these
            intervals to declare the connection dead; thus, the default
            setting of 1500 milliseconds causes the management node to
            wait for approximately 1600 ms before timing out.
     </p>
    </li>
   </ul>
  </div>
  <div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
   <div class="admon-title">
    Note
   </div>
   <p>
    After making changes in a management node's
          configuration, it is necessary to perform a rolling restart of
          the cluster for the new configuration to take effect.
   </p>
   <p>
    To add new management servers to a running NDB Cluster, it is
          also necessary to perform a rolling restart of all cluster
          nodes after modifying any existing
    <code class="filename">
     config.ini
    </code>
    files. For more information
          about issues arising when using multiple management nodes, see
    <a class="xref" href="mysql-cluster-limitations-multiple-nodes.html" title="25.2.7.10 Limitations Relating to Multiple NDB Cluster Nodes">
     Section 25.2.7.10, “Limitations Relating to Multiple NDB Cluster Nodes”
    </a>
    .
   </p>
  </div>
  <p>
   <a name="mysql-cluster-mgm-definition-restart-types">
   </a>
   <b>
    Restart types.
   </b>
   Information about the restart types used by the parameter
          descriptions in this section is shown in the following table:
  </p>
  <div class="table">
   <a name="idm46045120015136">
   </a>
   <p class="title">
    <b>
     Table 25.8 NDB Cluster restart types
    </b>
   </p>
   <div class="table-contents">
    <table>
     <colgroup>
      <col style="width: 10%"/>
      <col style="width: 30%"/>
      <col style="width: 60%"/>
     </colgroup>
     <thead>
      <tr>
       <th scope="col">
        Symbol
       </th>
       <th scope="col">
        Restart Type
       </th>
       <th scope="col">
        Description
       </th>
      </tr>
     </thead>
     <tbody>
      <tr>
       <th scope="row">
        N
       </th>
       <td>
        Node
       </td>
       <td>
        The parameter can be updated using a rolling restart (see
        <a class="xref" href="mysql-cluster-rolling-restart.html" title="25.6.5 Performing a Rolling Restart of an NDB Cluster">
         Section 25.6.5, “Performing a Rolling Restart of an NDB Cluster”
        </a>
        )
       </td>
      </tr>
      <tr>
       <th scope="row">
        S
       </th>
       <td>
        System
       </td>
       <td>
        All cluster nodes must be shut down completely, then restarted, to
              effect a change in this parameter
       </td>
      </tr>
      <tr>
       <th scope="row">
        I
       </th>
       <td>
        Initial
       </td>
       <td>
        Data nodes must be restarted using the
        <a class="link" href="mysql-cluster-programs-ndbd.html#option_ndbd_initial">
         <code class="option">
          --initial
         </code>
        </a>
        option
       </td>
      </tr>
     </tbody>
    </table>
   </div>
  </div>
  <br class="table-break"/>
 </div>
 <br/>
</div>
