<div id="docs-body">
 <div class="section">
  <div class="titlepage">
   <div>
    <div>
     <h3 class="title">
      <a name="innodb-redo-log">
      </a>
      17.6.5 Redo Log
     </h3>
    </div>
   </div>
  </div>
  <a class="indexterm" name="idm46045164868480">
  </a>
  <a class="indexterm" name="idm46045164867088">
  </a>
  <p>
   The redo log is a disk-based data structure used during crash
      recovery to correct data written by incomplete transactions.
      During normal operations, the redo log encodes requests to change
      table data that result from SQL statements or low-level API calls.
      Modifications that did not finish updating data files before an
      unexpected shutdown are replayed automatically during
      initialization and before connections are accepted. For
      information about the role of the redo log in crash recovery, see
   <a class="xref" href="innodb-recovery.html" title="17.18.2 InnoDB Recovery">
    Section 17.18.2, “InnoDB Recovery”
   </a>
   .
  </p>
  <p>
   The redo log is physically represented on disk by redo log files.
      Data that is written to redo log files is encoded in terms of
      records affected, and this data is collectively referred to as
      redo. The passage of data through redo log files is represented by
      an ever-increasing
   <a class="link" href="glossary.html#glos_lsn" title="LSN">
    LSN
   </a>
   value. Redo
      log data is appended as data modifications occur, and the oldest
      data is truncated as the checkpoint progresses.
  </p>
  <p>
   Information and procedures related to redo logs are described
      under the following topics in the section:
  </p>
  <div class="itemizedlist">
   <ul class="itemizedlist" style="list-style-type: disc; ">
    <li class="listitem">
     <p>
      <a class="xref" href="innodb-redo-log.html#innodb-modifying-redo-log-capacity" title="Configuring Redo Log Capacity">
       Configuring Redo Log Capacity
      </a>
     </p>
    </li>
    <li class="listitem">
     <p>
      <a class="xref" href="innodb-redo-log.html#innodb-redo-log-capacity-automatic-configuration" title="Automatic Redo Log Capacity Configuration">
       Automatic Redo Log Capacity Configuration
      </a>
     </p>
    </li>
    <li class="listitem">
     <p>
      <a class="xref" href="innodb-redo-log.html#innodb-redo-log-archiving" title="Redo Log Archiving">
       Redo Log Archiving
      </a>
     </p>
    </li>
    <li class="listitem">
     <p>
      <a class="xref" href="innodb-redo-log.html#innodb-disable-redo-logging" title="Disabling Redo Logging">
       Disabling Redo Logging
      </a>
     </p>
    </li>
    <li class="listitem">
     <p>
      <a class="xref" href="innodb-redo-log.html#innodb-redo-log-related-topics" title="Related Topics">
       Related Topics
      </a>
     </p>
    </li>
   </ul>
  </div>
  <div class="simplesect">
   <div class="titlepage">
    <div>
     <div class="simple">
      <h4 class="title">
       <a name="innodb-modifying-redo-log-capacity">
       </a>
       Configuring Redo Log Capacity
      </h4>
     </div>
    </div>
   </div>
   <a class="indexterm" name="idm46045164857728">
   </a>
   <a class="indexterm" name="idm46045164856336">
   </a>
   <p>
    The
    <a class="link" href="innodb-parameters.html#sysvar_innodb_redo_log_capacity">
     <code class="literal">
      innodb_redo_log_capacity
     </code>
    </a>
    system variable controls the amount of disk space occupied by
        redo log files. You can set this variable in an option file at
        startup or at runtime using a
    <a class="link" href="set-variable.html" title="15.7.6.1 SET Syntax for Variable Assignment">
     <code class="literal">
      SET
        GLOBAL
     </code>
    </a>
    statement; for example, the following statement
        sets the redo log capacity to 8GB:
   </p>
   <div class="copytoclipboard-wrapper">
    <pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa89019147"><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 keyword">SET</span> <span class="token keyword">GLOBAL</span> innodb_redo_log_capacity <span class="token operator">=</span> <span class="token number">8589934592</span><span class="token punctuation">;</span></code></pre>
   </div>
   <p>
    When set at runtime, the configuration change occurs immediately
        but it may take some time for the new limit to be fully
        implemented. If the redo log files occupy less space than the
        specified value, dirty pages are flushed from the buffer pool to
        tablespace data files less aggressively, eventually increasing
        the disk space occupied by the redo log files. If the redo log
        files occupy more space than the specified value, dirty pages
        are flushed more aggressively, eventually decreasing the disk
        space occupied by redo log files.
   </p>
   <p>
    If
    <code class="literal">
     innodb_redo_log_capacity
    </code>
    is not defined,
        and if neither
    <code class="literal">
     innodb_log_file_size
    </code>
    or
    <code class="literal">
     innodb_log_files_in_group
    </code>
    are defined, then
        the default
    <code class="literal">
     innodb_redo_log_capacity
    </code>
    value is
        used.
   </p>
   <p>
    If
    <code class="literal">
     innodb_redo_log_capacity
    </code>
    is not defined,
        and if
    <code class="literal">
     innodb_log_file_size
    </code>
    and/or
    <code class="literal">
     innodb_log_files_in_group
    </code>
    is defined, then
        the InnoDB redo log capacity is calculated as
    <span class="emphasis">
     <em>
      (innodb_log_files_in_group *
        innodb_log_file_size)
     </em>
    </span>
    . This calculation does not
        modify the unused
    <code class="literal">
     innodb_redo_log_capacity
    </code>
    setting's value.
   </p>
   <p>
    The
    <a class="link" href="server-status-variables.html#statvar_Innodb_redo_log_capacity_resized">
     <code class="literal">
      Innodb_redo_log_capacity_resized
     </code>
    </a>
    server status variable indicates the total redo log capacity for
        all redo log files.
   </p>
   <p>
    Redo log files reside in the
    <code class="filename">
     #innodb_redo
    </code>
    directory in the data directory unless a different directory was
        specified by the
    <a class="link" href="innodb-parameters.html#sysvar_innodb_log_group_home_dir">
     <code class="literal">
      innodb_log_group_home_dir
     </code>
    </a>
    variable. If
    <a class="link" href="innodb-parameters.html#sysvar_innodb_log_group_home_dir">
     <code class="literal">
      innodb_log_group_home_dir
     </code>
    </a>
    was
        defined, the redo log files reside in the
    <code class="filename">
     #innodb_redo
    </code>
    directory in that directory.
        There are two types of redo log files, ordinary and spare.
        Ordinary redo log files are those being used. Spare redo log
        files are those waiting to be used.
    <code class="literal">
     InnoDB
    </code>
    tries to maintain 32 redo log files in total, with each file
        equal in size to 1/32 *
    <code class="literal">
     innodb_redo_log_capacity
    </code>
    ; however, file sizes
        may differ for a time after modifying the
    <code class="literal">
     innodb_redo_log_capacity
    </code>
    setting.
   </p>
   <p>
    Redo log files use an
    <code class="filename">
     #ib_redo
     <em class="replaceable">
      <code>
       N
      </code>
     </em>
    </code>
    naming
        convention, where
    <em class="replaceable">
     <code>
      N
     </code>
    </em>
    is the redo log
        file number. Spare redo log files are denoted by a
    <code class="filename">
     _tmp
    </code>
    suffix. The following example shows
        the redo log files in an
    <code class="filename">
     #innodb_redo
    </code>
    directory, where there are 21 active redo log files and 11 spare
        redo log files, numbered sequentially.
   </p>
   <div class="copytoclipboard-wrapper">
    <pre class="programlisting language-simple"><div class="docs-select-all right" id="sa11910901"><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">'<span class="token comment" spellcheck="true">#ib_redo582'  '#ib_redo590'  '#ib_redo598'      '#ib_redo606_tmp'</span>
'<span class="token comment" spellcheck="true">#ib_redo583'  '#ib_redo591'  '#ib_redo599'      '#ib_redo607_tmp'</span>
'<span class="token comment" spellcheck="true">#ib_redo584'  '#ib_redo592'  '#ib_redo600'      '#ib_redo608_tmp'</span>
'<span class="token comment" spellcheck="true">#ib_redo585'  '#ib_redo593'  '#ib_redo601'      '#ib_redo609_tmp'</span>
'<span class="token comment" spellcheck="true">#ib_redo586'  '#ib_redo594'  '#ib_redo602'      '#ib_redo610_tmp'</span>
'<span class="token comment" spellcheck="true">#ib_redo587'  '#ib_redo595'  '#ib_redo603_tmp'  '#ib_redo611_tmp'</span>
'<span class="token comment" spellcheck="true">#ib_redo588'  '#ib_redo596'  '#ib_redo604_tmp'  '#ib_redo612_tmp'</span>
'<span class="token comment" spellcheck="true">#ib_redo589'  '#ib_redo597'  '#ib_redo605_tmp'  '#ib_redo613_tmp'</span></code></pre>
   </div>
   <p>
    Each ordinary redo log file is associated with a particular
        range of LSN values; for example, the following query shows the
    <code class="literal">
     START_LSN
    </code>
    and
    <code class="literal">
     END_LSN
    </code>
    values for the active redo log files listed in the previous
        example:
   </p>
   <div class="copytoclipboard-wrapper">
    <pre class="programlisting language-sql"><div class="docs-select-all right" id="sa60101669"><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> FILE_NAME<span class="token punctuation">,</span> START_LSN<span class="token punctuation">,</span> END_LSN <span class="token keyword">FROM</span> performance_schema<span class="token punctuation">.</span>innodb_redo_log_files<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>
<span class="token output"><span class="token punctuation">|</span> FILE_NAME                  <span class="token punctuation">|</span> START_LSN    <span class="token punctuation">|</span> END_LSN      <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>
<span class="token output"><span class="token punctuation">|</span> ./#innodb_redo/#ib_redo582 <span class="token punctuation">|</span> 117654982144 <span class="token punctuation">|</span> 117658256896 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> ./#innodb_redo/#ib_redo583 <span class="token punctuation">|</span> 117658256896 <span class="token punctuation">|</span> 117661531648 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> ./#innodb_redo/#ib_redo584 <span class="token punctuation">|</span> 117661531648 <span class="token punctuation">|</span> 117664806400 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> ./#innodb_redo/#ib_redo585 <span class="token punctuation">|</span> 117664806400 <span class="token punctuation">|</span> 117668081152 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> ./#innodb_redo/#ib_redo586 <span class="token punctuation">|</span> 117668081152 <span class="token punctuation">|</span> 117671355904 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> ./#innodb_redo/#ib_redo587 <span class="token punctuation">|</span> 117671355904 <span class="token punctuation">|</span> 117674630656 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> ./#innodb_redo/#ib_redo588 <span class="token punctuation">|</span> 117674630656 <span class="token punctuation">|</span> 117677905408 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> ./#innodb_redo/#ib_redo589 <span class="token punctuation">|</span> 117677905408 <span class="token punctuation">|</span> 117681180160 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> ./#innodb_redo/#ib_redo590 <span class="token punctuation">|</span> 117681180160 <span class="token punctuation">|</span> 117684454912 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> ./#innodb_redo/#ib_redo591 <span class="token punctuation">|</span> 117684454912 <span class="token punctuation">|</span> 117687729664 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> ./#innodb_redo/#ib_redo592 <span class="token punctuation">|</span> 117687729664 <span class="token punctuation">|</span> 117691004416 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> ./#innodb_redo/#ib_redo593 <span class="token punctuation">|</span> 117691004416 <span class="token punctuation">|</span> 117694279168 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> ./#innodb_redo/#ib_redo594 <span class="token punctuation">|</span> 117694279168 <span class="token punctuation">|</span> 117697553920 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> ./#innodb_redo/#ib_redo595 <span class="token punctuation">|</span> 117697553920 <span class="token punctuation">|</span> 117700828672 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> ./#innodb_redo/#ib_redo596 <span class="token punctuation">|</span> 117700828672 <span class="token punctuation">|</span> 117704103424 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> ./#innodb_redo/#ib_redo597 <span class="token punctuation">|</span> 117704103424 <span class="token punctuation">|</span> 117707378176 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> ./#innodb_redo/#ib_redo598 <span class="token punctuation">|</span> 117707378176 <span class="token punctuation">|</span> 117710652928 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> ./#innodb_redo/#ib_redo599 <span class="token punctuation">|</span> 117710652928 <span class="token punctuation">|</span> 117713927680 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> ./#innodb_redo/#ib_redo600 <span class="token punctuation">|</span> 117713927680 <span class="token punctuation">|</span> 117717202432 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> ./#innodb_redo/#ib_redo601 <span class="token punctuation">|</span> 117717202432 <span class="token punctuation">|</span> 117720477184 <span class="token punctuation">|</span></span>
<span class="token output"><span class="token punctuation">|</span> ./#innodb_redo/#ib_redo602 <span class="token punctuation">|</span> 117720477184 <span class="token punctuation">|</span> 117723751936 <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></code></pre>
   </div>
   <p>
    When doing a checkpoint,
    <code class="literal">
     InnoDB
    </code>
    stores the
        checkpoint LSN in the header of the file which contains this
        LSN. During recovery, all redo log files are checked and
        recovery starts at the latest checkpoint LSN.
   </p>
   <p>
    Several status variables are provided for monitoring the redo
        log and redo log capacity resize operations; for example, you
        can query
    <a class="link" href="server-status-variables.html#statvar_Innodb_redo_log_resize_status">
     <code class="literal">
      Innodb_redo_log_resize_status
     </code>
    </a>
    to view the status of a resize operation:
   </p>
   <div class="copytoclipboard-wrapper">
    <pre class="programlisting language-sql"><div class="docs-select-all right" id="sa918276"><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">SHOW</span> <span class="token keyword">STATUS</span> <span class="token operator">LIKE</span> <span class="token string">'Innodb_redo_log_resize_status'</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>
<span class="token output"><span class="token punctuation">|</span> Variable_name                 <span class="token punctuation">|</span> Value <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>
<span class="token output"><span class="token punctuation">|</span> Innodb_redo_log_resize_status <span class="token punctuation">|</span> OK    <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></code></pre>
   </div>
   <p>
    The
    <a class="link" href="server-status-variables.html#statvar_Innodb_redo_log_capacity_resized">
     <code class="literal">
      Innodb_redo_log_capacity_resized
     </code>
    </a>
    status variable shows the current redo log capacity limit:
   </p>
   <div class="copytoclipboard-wrapper">
    <pre class="programlisting language-sql"><div class="docs-select-all right" id="sa30349956"><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">SHOW</span> <span class="token keyword">STATUS</span> <span class="token operator">LIKE</span> <span class="token string">'Innodb_redo_log_capacity_resized'</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>
<span class="token output"><span class="token punctuation">|</span> Variable_name                    <span class="token punctuation">|</span> Value     <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>
<span class="token output"><span class="token punctuation">|</span> Innodb_redo_log_capacity_resized <span class="token punctuation">|</span> 104857600 <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></code></pre>
   </div>
   <p>
    Other applicable status variables include:
   </p>
   <div class="itemizedlist">
    <ul class="itemizedlist" style="list-style-type: disc; ">
     <li class="listitem">
      <p>
       <a class="link" href="server-status-variables.html#statvar_Innodb_redo_log_checkpoint_lsn">
        <code class="literal">
         Innodb_redo_log_checkpoint_lsn
        </code>
       </a>
      </p>
     </li>
     <li class="listitem">
      <p>
       <a class="link" href="server-status-variables.html#statvar_Innodb_redo_log_current_lsn">
        <code class="literal">
         Innodb_redo_log_current_lsn
        </code>
       </a>
      </p>
     </li>
     <li class="listitem">
      <p>
       <a class="link" href="server-status-variables.html#statvar_Innodb_redo_log_flushed_to_disk_lsn">
        <code class="literal">
         Innodb_redo_log_flushed_to_disk_lsn
        </code>
       </a>
      </p>
     </li>
     <li class="listitem">
      <p>
       <a class="link" href="server-status-variables.html#statvar_Innodb_redo_log_logical_size">
        <code class="literal">
         Innodb_redo_log_logical_size
        </code>
       </a>
      </p>
     </li>
     <li class="listitem">
      <p>
       <a class="link" href="server-status-variables.html#statvar_Innodb_redo_log_physical_size">
        <code class="literal">
         Innodb_redo_log_physical_size
        </code>
       </a>
      </p>
     </li>
     <li class="listitem">
      <p>
       <a class="link" href="server-status-variables.html#statvar_Innodb_redo_log_read_only">
        <code class="literal">
         Innodb_redo_log_read_only
        </code>
       </a>
      </p>
     </li>
     <li class="listitem">
      <p>
       <a class="link" href="server-status-variables.html#statvar_Innodb_redo_log_uuid">
        <code class="literal">
         Innodb_redo_log_uuid
        </code>
       </a>
      </p>
     </li>
    </ul>
   </div>
   <p>
    Refer to the status variable descriptions for more information.
   </p>
   <p>
    You can view information about active redo log files by querying
        the
    <a class="link" href="performance-schema-innodb-redo-log-files-table.html" title="29.12.22.4 The innodb_redo_log_files Table">
     <code class="literal">
      innodb_redo_log_files
     </code>
    </a>
    Performance Schema table. The following query retrieves data
        from all of the table's columns:
   </p>
   <div class="copytoclipboard-wrapper">
    <pre class="programlisting language-sql"><div class="docs-select-all right" id="sa90470680"><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 keyword">SELECT</span> FILE_ID<span class="token punctuation">,</span> START_LSN<span class="token punctuation">,</span> END_LSN<span class="token punctuation">,</span> SIZE_IN_BYTES<span class="token punctuation">,</span> IS_FULL<span class="token punctuation">,</span> CONSUMER_LEVEL 
<span class="token keyword">FROM</span> performance_schema<span class="token punctuation">.</span>innodb_redo_log_files<span class="token punctuation">;</span></code></pre>
   </div>
  </div>
  <div class="simplesect">
   <div class="titlepage">
    <div>
     <div class="simple">
      <h4 class="title">
       <a name="innodb-redo-log-capacity-automatic-configuration">
       </a>
       Automatic Redo Log Capacity Configuration
      </h4>
     </div>
    </div>
   </div>
   <p>
    When the server is started with
    <a class="link" href="innodb-parameters.html#option_mysqld_innodb-dedicated-server">
     <code class="option">
      --innodb-dedicated-server
     </code>
    </a>
    ,
    <code class="literal">
     InnoDB
    </code>
    automatically calculates and sets the
        values for certain
    <code class="literal">
     InnoDB
    </code>
    parameters,
        including redo log capacity. Automated configuration is intended
        for MySQL instances that reside on a server dedicated to MySQL,
        where the MySQL server can use all available system resources.
        For more information, see
    <a class="xref" href="innodb-dedicated-server.html" title="17.8.12 Enabling Automatic InnoDB Configuration for a Dedicated MySQL Server">
     Section 17.8.12, “Enabling Automatic InnoDB Configuration for a Dedicated MySQL Server”
    </a>
    .
   </p>
  </div>
  <div class="simplesect">
   <div class="titlepage">
    <div>
     <div class="simple">
      <h4 class="title">
       <a name="innodb-redo-log-archiving">
       </a>
       Redo Log Archiving
      </h4>
     </div>
    </div>
   </div>
   <a class="indexterm" name="idm46045164797824">
   </a>
   <p>
    Backup utilities that copy redo log records may sometimes fail
        to keep pace with redo log generation while a backup operation
        is in progress, resulting in lost redo log records due to those
        records being overwritten. This issue most often occurs when
        there is significant MySQL server activity during the backup
        operation, and the redo log file storage media operates at a
        faster speed than the backup storage media. The redo log
        archiving feature addresses this issue by sequentially writing
        redo log records to an archive file in addition to the redo log
        files. Backup utilities can copy redo log records from the
        archive file as necessary, thereby avoiding the potential loss
        of data.
   </p>
   <p>
    If redo log archiving is configured on the server,
    <a class="ulink" href="/doc/mysql-enterprise-backup/en/" target="_top">
     MySQL Enterprise Backup
    </a>
    ,
        available with
    <a class="ulink" href="https://www.mysql.com/products/enterprise/" target="_blank">
     MySQL Enterprise Edition
    </a>
    ,
        uses the redo log archiving feature when backing up a MySQL
        server.
   </p>
   <p>
    Enabling redo log archiving on the server requires setting a
        value for the
    <a class="link" href="innodb-parameters.html#sysvar_innodb_redo_log_archive_dirs">
     <code class="literal">
      innodb_redo_log_archive_dirs
     </code>
    </a>
    system variable. The value is specified as a semicolon-separated
        list of labeled redo log archive directories. The
    <code class="literal">
     <em class="replaceable">
      <code>
       label
      </code>
     </em>
     :
     <em class="replaceable">
      <code>
       directory
      </code>
     </em>
    </code>
    pair is separated by a colon (
    <code class="literal">
     :
    </code>
    ). For
        example:
   </p>
   <div class="copytoclipboard-wrapper">
    <pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa43071840"><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">SET</span> <span class="token keyword">GLOBAL</span> innodb_redo_log_archive_dirs<span class="token operator">=</span><span class="token string">'<em class="replaceable">label1</em>:<em class="replaceable">directory_path1</em>[;<em class="replaceable">label2</em>:<em class="replaceable">directory_path2</em>;…]'</span><span class="token punctuation">;</span></code></pre>
   </div>
   <p>
    The
    <em class="replaceable">
     <code>
      label
     </code>
    </em>
    is an arbitrary identifier
        for the archive directory. It can be any string of characters,
        with the exception of colons (:), which are not permitted. An
        empty label is also permitted, but the colon (:) is still
        required in this case. A
    <em class="replaceable">
     <code>
      directory_path
     </code>
    </em>
    must be specified. The
        directory selected for the redo log archive file must exist when
        redo log archiving is activated, or an error is returned. The
        path can contain colons (':'), but semicolons (;) are not
        permitted.
   </p>
   <p>
    The
    <a class="link" href="innodb-parameters.html#sysvar_innodb_redo_log_archive_dirs">
     <code class="literal">
      innodb_redo_log_archive_dirs
     </code>
    </a>
    variable must be configured before redo log archiving can be
        activated. The default value is
    <code class="literal">
     NULL
    </code>
    , which
        does not permit activating redo log archiving.
   </p>
   <div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
    <div class="admon-title">
     Notes
    </div>
    <p>
     The archive directories that you specify must satisfy the
          following requirements. (The requirements are enforced when
          redo log archiving is activated.):
    </p>
    <div class="itemizedlist">
     <ul class="itemizedlist" style="list-style-type: disc; ">
      <li class="listitem">
       <p>
        Directories must exist. Directories are not created by the
              redo log archive process. Otherwise, the following error
              is returned:
       </p>
       <p>
        <span class="errortext">
         ERROR 3844 (HY000): Redo log archive directory
              '
         <em class="replaceable">
          <code>
           directory_path1
          </code>
         </em>
         ' does not
              exist or is not a directory
        </span>
       </p>
      </li>
      <li class="listitem">
       <p>
        Directories must not be world-accessible. This is to
              prevent the redo log data from being exposed to
              unauthorized users on the system. Otherwise, the following
              error is returned:
       </p>
       <p>
        <span class="errortext">
         ERROR 3846 (HY000): Redo log archive directory
              '
         <em class="replaceable">
          <code>
           directory_path1
          </code>
         </em>
         ' is accessible
              to all OS users
        </span>
       </p>
      </li>
      <li class="listitem">
       <p>
        Directories cannot be those defined by
        <a class="link" href="server-system-variables.html#sysvar_datadir">
         <code class="literal">
          datadir
         </code>
        </a>
        ,
        <a class="link" href="innodb-parameters.html#sysvar_innodb_data_home_dir">
         <code class="literal">
          innodb_data_home_dir
         </code>
        </a>
        ,
        <a class="link" href="innodb-parameters.html#sysvar_innodb_directories">
         <code class="literal">
          innodb_directories
         </code>
        </a>
        ,
        <a class="link" href="innodb-parameters.html#sysvar_innodb_log_group_home_dir">
         <code class="literal">
          innodb_log_group_home_dir
         </code>
        </a>
        ,
        <a class="link" href="innodb-parameters.html#sysvar_innodb_temp_tablespaces_dir">
         <code class="literal">
          innodb_temp_tablespaces_dir
         </code>
        </a>
        ,
        <a class="link" href="innodb-parameters.html#sysvar_innodb_tmpdir">
         <code class="literal">
          innodb_tmpdir
         </code>
        </a>
        <a class="link" href="innodb-parameters.html#sysvar_innodb_undo_directory">
         <code class="literal">
          innodb_undo_directory
         </code>
        </a>
        , or
        <a class="link" href="server-system-variables.html#sysvar_secure_file_priv">
         <code class="literal">
          secure_file_priv
         </code>
        </a>
        , nor can
              they be parent directories or subdirectories of those
              directories. Otherwise, an error similar to the following
              is returned:
       </p>
       <p>
        <span class="errortext">
         ERROR 3845 (HY000): Redo log archive directory
              '
         <em class="replaceable">
          <code>
           directory_path1
          </code>
         </em>
         ' is in, under,
              or over server directory 'datadir' -
              '
         <em class="replaceable">
          <code>
           /path/to/data_directory
          </code>
         </em>
         '
        </span>
       </p>
      </li>
     </ul>
    </div>
   </div>
   <p>
    When a backup utility that supports redo log archiving initiates
        a backup, the backup utility activates redo log archiving by
        invoking the
    <code class="literal">
     innodb_redo_log_archive_start()
    </code>
    function.
   </p>
   <p>
    If you are not using a backup utility that supports redo log
        archiving, redo log archiving can also be activated manually, as
        shown:
   </p>
   <div class="copytoclipboard-wrapper">
    <pre class="programlisting language-sql"><div class="docs-select-all right" id="sa65331819"><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> innodb_redo_log_archive_start<span class="token punctuation">(</span><span class="token string">'<em class="replaceable">label</em>'</span><span class="token punctuation">,</span> <span class="token string">'<em class="replaceable">subdir</em>'</span><span class="token punctuation">)</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>
<span class="token output"><span class="token punctuation">|</span> innodb_redo_log_archive_start('<em class="replaceable">label</em>') <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>
<span class="token output"><span class="token punctuation">|</span> 0                                        <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></code></pre>
   </div>
   <p>
    Or:
   </p>
   <div class="copytoclipboard-wrapper">
    <pre class="programlisting language-sql"><div class="docs-select-all right" id="sa88164451"><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">DO</span> innodb_redo_log_archive_start<span class="token punctuation">(</span><span class="token string">'<em class="replaceable">label</em>'</span><span class="token punctuation">,</span> <span class="token string">'<em class="replaceable">subdir</em>'</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token output">Query OK, 0 rows affected (0.09 sec)</span></code></pre>
   </div>
   <div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
    <div class="admon-title">
     Note
    </div>
    <p>
     The MySQL session that activates redo log archiving (using
     <code class="literal">
      innodb_redo_log_archive_start()
     </code>
     ) must
          remain open for the duration of the archiving. The same
          session must deactivate redo log archiving (using
     <code class="literal">
      innodb_redo_log_archive_stop()
     </code>
     ). If the
          session is terminated before the redo log archiving is
          explicitly deactivated, the server deactivates redo log
          archiving implicitly and removes the redo log archive file.
    </p>
   </div>
   <p>
    where
    <em class="replaceable">
     <code>
      label
     </code>
    </em>
    is a label defined by
    <a class="link" href="innodb-parameters.html#sysvar_innodb_redo_log_archive_dirs">
     <code class="literal">
      innodb_redo_log_archive_dirs
     </code>
    </a>
    ;
    <code class="literal">
     subdir
    </code>
    is an optional argument for specifying
        a subdirectory of the directory identified by
    <em class="replaceable">
     <code>
      label
     </code>
    </em>
    for saving the archive file; it
        must be a simple directory name (no slash (/), backslash (\), or
        colon (:) is permitted).
    <code class="literal">
     subdir
    </code>
    can be empty,
        null, or it can be left out.
   </p>
   <p>
    Only users with the
    <a class="link" href="privileges-provided.html#priv_innodb-redo-log-archive">
     <code class="literal">
      INNODB_REDO_LOG_ARCHIVE
     </code>
    </a>
    privilege
        can activate redo log archiving by invoking
    <code class="literal">
     innodb_redo_log_archive_start()
    </code>
    , or
        deactivate it using
    <code class="literal">
     innodb_redo_log_archive_stop()
    </code>
    . The MySQL
        user running the backup utility or the MySQL user activating and
        deactivating redo log archiving manually must have this
        privilege.
   </p>
   <p>
    The redo log archive file path is
    <code class="filename">
     <em class="replaceable">
      <code>
       directory_identified_by_label
      </code>
     </em>
     /[
     <em class="replaceable">
      <code>
       subdir
      </code>
     </em>
     /]archive.
     <em class="replaceable">
      <code>
       serverUUID
      </code>
     </em>
     .000001.log
    </code>
    ,
        where
    <code class="filename">
     <em class="replaceable">
      <code>
       directory_identified_by_label
      </code>
     </em>
    </code>
    is the archive directory identified by the
    <code class="literal">
     <em class="replaceable">
      <code>
       label
      </code>
     </em>
    </code>
    argument for
    <code class="literal">
     innodb_redo_log_archive_start()
    </code>
    .
    <code class="filename">
     <em class="replaceable">
      <code>
       subdir
      </code>
     </em>
    </code>
    is the
        optional argument used for
    <code class="literal">
     innodb_redo_log_archive_start()
    </code>
    .
   </p>
   <p>
    For example, the full path and name for a redo log archive file
        appears similar to the following:
   </p>
   <div class="copytoclipboard-wrapper">
    <pre class="programlisting one-line language-terminal"><div class="docs-select-all right" id="sa27049542"><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-terminal">/<em class="replaceable">directory_path</em>/<em class="replaceable">subdirectory</em>/archive<span class="token punctuation">.</span>e71a47dc-61f8-11e9-a3cb-080027154b4d<span class="token punctuation">.</span>000001<span class="token punctuation">.</span>log</code></pre>
   </div>
   <p>
    After the backup utility finishes copying
    <code class="literal">
     InnoDB
    </code>
    data files, it deactivates redo log
        archiving by calling the
    <code class="literal">
     innodb_redo_log_archive_stop()
    </code>
    function.
   </p>
   <p>
    If you are not using a backup utility that supports redo log
        archiving, redo log archiving can also be deactivated manually,
        as shown:
   </p>
   <div class="copytoclipboard-wrapper">
    <pre class="programlisting language-sql"><div class="docs-select-all right" id="sa62752200"><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> innodb_redo_log_archive_stop<span class="token punctuation">(</span><span class="token punctuation">)</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>
<span class="token output"><span class="token punctuation">|</span> innodb_redo_log_archive_stop() <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>
<span class="token output"><span class="token punctuation">|</span> 0                              <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></code></pre>
   </div>
   <p>
    Or:
   </p>
   <div class="copytoclipboard-wrapper">
    <pre class="programlisting language-sql"><div class="docs-select-all right" id="sa92711235"><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">DO</span> innodb_redo_log_archive_stop<span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token output">Query OK, 0 rows affected (0.01 sec)</span></code></pre>
   </div>
   <p>
    After the stop function completes successfully, the backup
        utility looks for the relevant section of redo log data from the
        archive file and copies it into the backup.
   </p>
   <p>
    After the backup utility finishes copying the redo log data and
        no longer needs the redo log archive file, it deletes the
        archive file.
   </p>
   <p>
    Removal of the archive file is the responsibility of the backup
        utility in normal situations. However, if the redo log archiving
        operation quits unexpectedly before
    <code class="literal">
     innodb_redo_log_archive_stop()
    </code>
    is called, the
        MySQL server removes the file.
   </p>
   <h5>
    <a name="idm46045164734160">
    </a>
    Performance Considerations
   </h5>
   <p>
    Activating redo log archiving typically has a minor performance
        cost due to the additional write activity.
   </p>
   <p>
    On Unix and Unix-like operating systems, the performance impact
        is typically minor, assuming there is not a sustained high rate
        of updates. On Windows, the performance impact is typically a
        bit higher, assuming the same.
   </p>
   <p>
    If there is a sustained high rate of updates and the redo log
        archive file is on the same storage media as the redo log files,
        the performance impact may be more significant due to compounded
        write activity.
   </p>
   <p>
    If there is a sustained high rate of updates and the redo log
        archive file is on slower storage media than the redo log files,
        performance is impacted arbitrarily.
   </p>
   <p>
    Writing to the redo log archive file does not impede normal
        transactional logging except in the case that the redo log
        archive file storage media operates at a much slower rate than
        the redo log file storage media, and there is a large backlog of
        persisted redo log blocks waiting to be written to the redo log
        archive file. In this case, the transactional logging rate is
        reduced to a level that can be managed by the slower storage
        media where the redo log archive file resides.
   </p>
  </div>
  <div class="simplesect">
   <div class="titlepage">
    <div>
     <div class="simple">
      <h4 class="title">
       <a name="innodb-disable-redo-logging">
       </a>
       Disabling Redo Logging
      </h4>
     </div>
    </div>
   </div>
   <p>
    You can disable redo logging using the
    <a class="link" href="alter-instance.html" title="15.1.5 ALTER INSTANCE Statement">
     <code class="literal">
      ALTER INSTANCE
        DISABLE INNODB REDO_LOG
     </code>
    </a>
    statement. This functionality
        is intended for loading data into a new MySQL instance.
        Disabling redo logging speeds up data loading by avoiding redo
        log writes and doublewrite buffering.
   </p>
   <div class="warning" style="margin-left: 0.5in; margin-right: 0.5in;">
    <div class="admon-title">
     Warning
    </div>
    <p>
     This feature is intended only for loading data into a new
          MySQL instance.
     <span class="emphasis">
      <em>
       Do not disable redo logging on a
          production system.
      </em>
     </span>
     It is permitted to shutdown and
          restart the server while redo logging is disabled, but an
          unexpected server stoppage while redo logging is disabled can
          cause data loss and instance corruption.
    </p>
    <p>
     Attempting to restart the server after an unexpected server
          stoppage while redo logging is disabled is refused with the
          following error:
    </p>
    <div class="copytoclipboard-wrapper">
     <pre class="programlisting language-terminal"><div class="docs-select-all right" id="sa93178817"><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-terminal"><span class="token property"><span class="token punctuation">[</span>ERROR<span class="token punctuation">]</span></span> <span class="token punctuation">[</span>MY-013598<span class="token punctuation">]</span> <span class="token punctuation">[</span>InnoDB<span class="token punctuation">]</span> Server was killed when Innodb Redo 
logging was disabled<span class="token punctuation">.</span> Data files could be corrupt<span class="token punctuation">.</span> You can try 
to restart the database with innodb_force_recovery<span class="token attr-value"><span class="token punctuation">=</span>6</span></code></pre>
    </div>
    <p>
     In this case, initialize a new MySQL instance and start the
          data loading procedure again.
    </p>
   </div>
   <p>
    The
    <a class="link" href="privileges-provided.html#priv_innodb-redo-log-enable">
     <code class="literal">
      INNODB_REDO_LOG_ENABLE
     </code>
    </a>
    privilege is required to enable and disable redo logging.
   </p>
   <p>
    The
    <a class="link" href="server-status-variables.html#statvar_Innodb_redo_log_enabled">
     <code class="literal">
      Innodb_redo_log_enabled
     </code>
    </a>
    status variable permits monitoring redo logging status.
   </p>
   <p>
    Cloning operations and redo log archiving are not permitted
        while redo logging is disabled and vice versa.
   </p>
   <p>
    An
    <a class="link" href="alter-instance.html" title="15.1.5 ALTER INSTANCE Statement">
     <code class="literal">
      ALTER
        INSTANCE [ENABLE|DISABLE] INNODB REDO_LOG
     </code>
    </a>
    operation
        requires an exclusive backup metadata lock, which prevents other
    <a class="link" href="alter-instance.html" title="15.1.5 ALTER INSTANCE Statement">
     <code class="literal">
      ALTER INSTANCE
     </code>
    </a>
    operations from
        executing concurrently. Other
    <a class="link" href="alter-instance.html" title="15.1.5 ALTER INSTANCE Statement">
     <code class="literal">
      ALTER
        INSTANCE
     </code>
    </a>
    operations must wait for the lock to be
        released before executing.
   </p>
   <p>
    The following procedure demonstrates how to disable redo logging
        when loading data into a new MySQL instance.
   </p>
   <div class="orderedlist">
    <ol class="orderedlist" type="1">
     <li class="listitem">
      <p>
       On the new MySQL instance, grant the
       <a class="link" href="privileges-provided.html#priv_innodb-redo-log-enable">
        <code class="literal">
         INNODB_REDO_LOG_ENABLE
        </code>
       </a>
       privilege to the user account responsible for disabling redo
            logging.
      </p>
      <div class="copytoclipboard-wrapper">
       <pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa20906141"><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">GRANT</span> INNODB_REDO_LOG_ENABLE <span class="token keyword">ON</span> <span class="token operator">*</span><span class="token punctuation">.</span><span class="token operator">*</span> <span class="token keyword">to</span> <span class="token string">'data_load_admin'</span><span class="token punctuation">;</span></code></pre>
      </div>
     </li>
     <li class="listitem">
      <p>
       As the
       <code class="literal">
        data_load_admin
       </code>
       user, disable redo
            logging:
      </p>
      <div class="copytoclipboard-wrapper">
       <pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa86241723"><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">ALTER</span> <span class="token keyword">INSTANCE</span> <span class="token keyword">DISABLE</span> INNODB REDO_LOG<span class="token punctuation">;</span></code></pre>
      </div>
     </li>
     <li class="listitem">
      <p>
       Check the
       <a class="link" href="server-status-variables.html#statvar_Innodb_redo_log_enabled">
        <code class="literal">
         Innodb_redo_log_enabled
        </code>
       </a>
       status variable to ensure that redo logging is disabled.
      </p>
      <div class="copytoclipboard-wrapper">
       <pre class="programlisting language-sql"><div class="docs-select-all right" id="sa6442225"><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">SHOW</span> <span class="token keyword">GLOBAL</span> <span class="token keyword">STATUS</span> <span class="token operator">LIKE</span> <span class="token string">'Innodb_redo_log_enabled'</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>
<span class="token output"><span class="token punctuation">|</span> Variable_name           <span class="token punctuation">|</span> Value <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>
<span class="token output"><span class="token punctuation">|</span> Innodb_redo_log_enabled <span class="token punctuation">|</span> OFF   <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></code></pre>
      </div>
     </li>
     <li class="listitem">
      <p>
       Run the data load operation.
      </p>
     </li>
     <li class="listitem">
      <p>
       As the
       <code class="literal">
        data_load_admin
       </code>
       user, enable redo
            logging after the data load operation finishes:
      </p>
      <div class="copytoclipboard-wrapper">
       <pre class="programlisting one-line language-sql"><div class="docs-select-all right" id="sa76572622"><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">ALTER</span> <span class="token keyword">INSTANCE</span> <span class="token keyword">ENABLE</span> INNODB REDO_LOG<span class="token punctuation">;</span></code></pre>
      </div>
     </li>
     <li class="listitem">
      <p>
       Check the
       <a class="link" href="server-status-variables.html#statvar_Innodb_redo_log_enabled">
        <code class="literal">
         Innodb_redo_log_enabled
        </code>
       </a>
       status variable to ensure that redo logging is enabled.
      </p>
      <div class="copytoclipboard-wrapper">
       <pre class="programlisting language-sql"><div class="docs-select-all right" id="sa65695399"><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">SHOW</span> <span class="token keyword">GLOBAL</span> <span class="token keyword">STATUS</span> <span class="token operator">LIKE</span> <span class="token string">'Innodb_redo_log_enabled'</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>
<span class="token output"><span class="token punctuation">|</span> Variable_name           <span class="token punctuation">|</span> Value <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>
<span class="token output"><span class="token punctuation">|</span> Innodb_redo_log_enabled <span class="token punctuation">|</span> ON    <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></code></pre>
      </div>
     </li>
    </ol>
   </div>
  </div>
  <div class="simplesect">
   <div class="titlepage">
    <div>
     <div class="simple">
      <h4 class="title">
       <a name="innodb-redo-log-related-topics">
       </a>
       Related Topics
      </h4>
     </div>
    </div>
   </div>
   <div class="itemizedlist">
    <ul class="itemizedlist" style="list-style-type: disc; ">
     <li class="listitem">
      <p>
       <a class="xref" href="innodb-init-startup-configuration.html#innodb-startup-log-file-configuration" title="Redo Log Configuration">
        Redo Log Configuration
       </a>
      </p>
     </li>
     <li class="listitem">
      <p>
       <a class="xref" href="optimizing-innodb-logging.html" title="10.5.4 Optimizing InnoDB Redo Logging">
        Section 10.5.4, “Optimizing InnoDB Redo Logging”
       </a>
      </p>
     </li>
     <li class="listitem">
      <p>
       <a class="xref" href="innodb-data-encryption.html#innodb-data-encryption-redo-log" title="Redo Log Encryption">
        Redo Log Encryption
       </a>
      </p>
     </li>
    </ul>
   </div>
  </div>
 </div>
 <br/>
</div>
