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     <h3 class="title">
      <a name="group-replication-replication-group-member-stats">
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      20.4.4 The replication_group_member_stats Table
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  <p>
   Each member in a replication group certifies and applies
      transactions received by the group. Statistics regarding the
      certifier and applier procedures are useful to understand how the
      applier queue is growing, how many conflicts have been found, how
      many transactions were checked, which transactions are committed
      everywhere, and so on.
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  <p>
   The
   <a class="link" href="performance-schema-replication-group-member-stats-table.html" title="29.12.11.15 The replication_group_member_stats Table">
    <code class="literal">
     performance_schema.replication_group_member_stats
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   table provides group-level information related to the
      certification process, and also statistics for the transactions
      received and originated by each individual member of the
      replication group. The information is shared between all the
      server instances that are members of the replication group, so
      information on all the group members can be queried from any
      member. Note that refreshing of statistics for remote members is
      controlled by the message period specified in the
   <a class="link" href="group-replication-system-variables.html#sysvar_group_replication_flow_control_period">
    <code class="literal">
     group_replication_flow_control_period
    </code>
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   option, so these can differ slightly from the locally collected
      statistics for the member where the query is made. To use this
      table to monitor a Group Replication member, issue the following
      statement:
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  <div class="copytoclipboard-wrapper">
   <pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa61691047"><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>replication_group_member_stats\G</code></pre>
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  <p>
   You can also use the following statement:
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  <div class="copytoclipboard-wrapper">
   <pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa26618271"><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">TABLE</span> performance_schema<span class="token punctuation">.</span>replication_group_member_stats\G</code></pre>
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  <p>
   These columns are important for monitoring the performance of the
      members connected in the group. Suppose that one of the
      group's members always reports a large number of transactions
      in its queue compared to other members. This means that the member
      is delayed and is not able to keep up to date with the other
      members of the group. Based on this information, you could decide
      to either remove the member from the group, or delay the
      processing of transactions on the other members of the group in
      order to reduce the number of queued transactions. This
      information can also help you to decide how to adjust the flow
      control of the Group Replication plugin, see
   <a class="xref" href="group-replication-flow-control.html" title="20.7.2 Flow Control">
    Section 20.7.2, “Flow Control”
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   .
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