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https://issues.apache.org/jira/browse/HBASE-12451?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14212065#comment-14212065
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Qiang Tian commented on HBASE-12451:
------------------------------------
bq. Add a minimum split size will break the first goal, right?
it is configurable, we can set the default minimum size to 0, the calculation
will ignore the minimum size in this case:(Pseudocode)
{code}
long splitSize = tableRegionsCount == 0 || tableRegionsCount > 100 ?
getDesiredMaxFileSize():
Math.min(getDesiredMaxFileSize(),
this.initialSize * tableRegionsCount * tableRegionsCount *
tableRegionsCount);
long minmumSize = conf.getLong("hbase.hregion.split.minimum.size", 0);
return minmumSize > 0 ? Math.max(splitSize, minmumSize) : splitSize;
}
{code}
bq. And actually, there is a "hbase.increasing.policy.initial.size"
configuration in IncreasingToUpperBoundRegionSplitPolicy which specify the
initial(minimum) split size.
beside initial.size, tableRegionsCount is also a variable.
bq. And if you do not like the curve of split size, I think we should introduce
a new split policy instead?
I do not mean I do not like it, it looks to me the case described in the jira
is not a common case? so a simple fix can resolve it quickly...if there are
other issues I am open for ideas :-)
> IncreasingToUpperBoundRegionSplitPolicy may cause unnecessary region splits
> in rolling update of cluster
> --------------------------------------------------------------------------------------------------------
>
> Key: HBASE-12451
> URL: https://issues.apache.org/jira/browse/HBASE-12451
> Project: HBase
> Issue Type: Bug
> Reporter: Liu Shaohui
> Assignee: Liu Shaohui
> Priority: Minor
> Fix For: 2.0.0
>
> Attachments: HBASE-12451-v1.diff
>
>
> Currently IncreasingToUpperBoundRegionSplitPolicy is the default region split
> policy. In this policy, split size is the number of regions that are on this
> server that all are of the same table, cubed, times 2x the region flush size.
> But when unloading regions of a regionserver in a cluster using
> region_mover.rb, the number of regions that are on this server that all are
> of the same table will decrease, and the split size will decrease too, which
> may cause the left region split in the regionsever. Region Splits also
> happens when loading regions of a regionserver in a cluster.
> A improvment may set a minimum split size in
> IncreasingToUpperBoundRegionSplitPolicy
> Suggestions are welcomed. Thanks~
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