HBASE-11782 Document that hbase.MetaMigrationConvertingToPB needs to be set to true for migrations pre 0.96 (Misty Stanley-Jones)

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Jonathan M Hsieh 2014-08-25 13:52:04 -07:00
parent f96dc97612
commit 7ed832a145
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@ -293,6 +293,21 @@ Successfully completed Log splitting
17:22:15 at Client_4_3_0.main(Client_4_3_0.java:63)</screen>
</section>
</section>
<section>
<title>Upgrading <code>META</code> to use Protocol Buffers (Protobuf)</title>
<para>When you upgrade from versions prior to 0.96, <code>META</code> needs to be
converted to use protocol buffers. This is controlled by the configuration
option <option>hbase.MetaMigrationConvertingToPB</option>, which is set to
<literal>true</literal> by default. Therefore, by default, no action is
required on your part.</para>
<para>The migration is a one-time event. However, every time your cluster starts,
<code>META</code> is scanned to ensure that it does not need to be
converted. If you have a very large number of regions, this scan can take a long
time. Starting in 0.98.5, you can set
<option>hbase.MetaMigrationConvertingToPB</option> to
<literal>false</literal> in <filename>hbase-site.xml</filename>, to disable
this start-up scan. This should be considered an expert-level setting.</para>
</section>
</section>