HBASE-11324 Update 2.5.2.8. Managed Compactions (Misty Stanley-Jones)

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stack 2014-06-24 17:15:55 -07:00
parent b26fb383cf
commit 05c1b27e6f
2 changed files with 14 additions and 9 deletions

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@ -3205,7 +3205,7 @@ myHtd.setValue(HTableDescriptor.SPLIT_POLICY, MyCustomSplitPolicy.class.getName(
</listitem>
</varlistentry>
</variablelist>
<table>
<table xlink:id="compaction.parameters">
<title>Parameters Used by Compaction Algorithm</title>
<textobject>
<para>This table contains the main configuration parameters for compaction. This

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@ -1387,14 +1387,19 @@ index e70ebc6..96f8c27 100644
<section
xml:id="managed.compactions">
<title>Managed Compactions</title>
<para>A common administrative technique is to manage major compactions manually, rather than
letting HBase do it. By default, <varname>HConstants.MAJOR_COMPACTION_PERIOD</varname> is
one day and major compactions may kick in when you least desire it - especially on a busy
system. To turn off automatic major compactions set the value to <varname>0</varname>. </para>
<para>It is important to stress that major compactions are absolutely necessary for
StoreFile cleanup, the only variant is when they occur. They can be administered through
the HBase shell, or via <link
xlink:href="http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/client/HBaseAdmin.html#majorCompact%28java.lang.String%29">HBaseAdmin</link>. </para>
<para>By default, major compactions are scheduled to run once in a 7-day period. Prior to HBase 0.96.x, major
compactions were scheduled to happen once per day by default.</para>
<para>If you need to control exactly when and how often major compaction runs, you can
disable managed major compactions. See the entry for
<varname>hbase.hregion.majorcompaction</varname> in the <xref
linkend="compaction.parameters" /> table for details.</para>
<warning>
<title>Do Not Disable Major Compactions</title>
<para>Major compactions are absolutely necessary for StoreFile clean-up. Do not disable
them altogether. You can run major compactions manually via the HBase shell or via the <link
xlink:href="http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/client/HBaseAdmin.html#majorCompact%28java.lang.String%29">HBaseAdmin
API</link>.</para>
</warning>
<para>For more information about compactions and the compaction file selection process, see <xref
linkend="compaction" /></para>
</section>