Add doc of since removed hbase.bucketcache.percentage.in.combinedcache
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@ -2263,6 +2263,23 @@ rs.close();
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<emphasis>Server Metrics: Memory</emphasis> tab in the UI.
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</para>
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</note>
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<note xml:id="hbase.bucketcache.percentage.in.combinedcache"><title>hbase.bucketcache.percentage.in.combinedcache</title>
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<para>This is a pre-HBase 1.0 configuration removed because it
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was confusing. It was a float that you would set to some value
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between 0.0 and 1.0. Its default was 0.9. If the deploy was using
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CombinedBlockCache, then the LruBlockCache L1 size was calculated to
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be (1 - <varname>hbase.bucketcache.percentage.in.combinedcache</varname>) * <varname>size-of-bucketcache</varname>
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and the BucketCache size was <varname>hbase.bucketcache.percentage.in.combinedcache</varname> * size-of-bucket-cache.
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where size-of-bucket-cache itself is EITHER the value of the configuration hbase.bucketcache.size
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IF it was specified as megabytes OR <varname>hbase.bucketcache.size</varname> * <varname>-XX:MaxDirectMemorySize</varname> if
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<varname>hbase.bucketcache.size</varname> between 0 and 1.0.
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</para>
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<para>In 1.0, it should be more straight-forward. L1 LruBlockCache size
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is set as a fraction of java heap using hfile.block.cache.size setting
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(not the best name) and L2 is set as above either in absolute
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megabytes or as a fraction of allocated maximum direct memory.
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</para>
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</note>
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</section>
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</section>
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</section>
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