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https://issues.apache.org/jira/browse/HBASE-3149?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13210687#comment-13210687
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Nicolas Spiegelberg commented on HBASE-3149:
--------------------------------------------
@Mubarak: I think you probably are more interested in tuning the compaction
settings. The initial reason for this JIRA was higher network IO. The actual
problem was that the min unconditional compact size was too high & caused bad
compaction decision. We fixed this by lowering the min size from the default
of the flush size (256MB, for us) to 4MB.
{code}
<property>
<name>hbase.hstore.compaction.min.size</name>
<value>4194304</value>
<description>
The "minimum" compaction size. All files below this size are always
included into a compaction, even if outside compaction ratio times
the total size of all files added to compaction so far.
</description>
</property>
{code}
We identified this a while ago and I thought we were going to change the
default for 0.92, but it looks like it's still in the Store.java code :( A
better use of your time would be to verify that this reduces your IO and write
up a JIRA to change the default.
> Make flush decisions per column family
> --------------------------------------
>
> Key: HBASE-3149
> URL: https://issues.apache.org/jira/browse/HBASE-3149
> Project: HBase
> Issue Type: Improvement
> Components: regionserver
> Reporter: Karthik Ranganathan
> Assignee: Nicolas Spiegelberg
>
> Today, the flush decision is made using the aggregate size of all column
> families. When large and small column families co-exist, this causes many
> small flushes of the smaller CF. We need to make per-CF flush decisions.
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