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https://issues.apache.org/jira/browse/HBASE-14460?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15036353#comment-15036353
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Bryan Beaudreault commented on HBASE-14460:
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Thank you [~stack]. One piece of feedback we have so far on CDAP after only a
couple days using it is that it is installed on a column family and thus
requires each CF it is installed on to have unlimited versions. We understand
why it requires unlimited versions in its current state to roll up the
increments, but this is awful when you have a column which is incremented in a
CF with other non-increment data. All of that other data will have unlimited
versions as well.
If something like CDAP were incorporated into hbase native I imagine there are
better ways to do this roll up. I just wanted to make sure I voiced this as a
great thing to improve upon: in the hbase-native version, we shouldn't need to
configure an entire CF to have unlimited versions if just 1 or 2 columns are
being incremented.
Also, the vast majority of our increments are write-only (we don't care about
the result at increment time). But a small handful do care about that value. So
having two different versions (one read-write, one write-only) would be great.
> [Perf Regression] Merge of MVCC and SequenceId (HBASE-HBASE-8763) slowed
> Increments, CheckAndPuts, batch operations
> -------------------------------------------------------------------------------------------------------------------
>
> Key: HBASE-14460
> URL: https://issues.apache.org/jira/browse/HBASE-14460
> Project: HBase
> Issue Type: Bug
> Components: Performance
> Reporter: stack
> Assignee: stack
> Priority: Critical
> Attachments: 14460.txt, region_lock.png
>
>
> As reported by 鈴木俊裕 up on the mailing list -- see "Performance degradation
> between CDH5.3.1(HBase0.98.6) and CDH5.4.5(HBase1.0.0)" -- our unification of
> sequenceid and MVCC slows Increments (and other ops) as the mvcc needs to
> 'catch up' to our current point before we can read the last Increment value
> that we need to update.
> We can say that our Increment is just done wrong, we should just be writing
> Increments and summing on read, but checkAndPut as well as batching
> operations have the same issue. Fix.
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