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https://issues.apache.org/jira/browse/HBASE-14460?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15055467#comment-15055467
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Heng Chen commented on HBASE-14460:
-----------------------------------
{quote}
If I run a test that has 100 threads each updating their own rows – i.e. no
contention on a row – then I see master branch completing before 0.94 does;
i.e. master is faster.
{quote}
are all the rows in one region?
> [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: 0.94.test.patch, 0.98.test.patch, 14460.txt,
> flamegraph-13120.svg.master.singlecell.svg, flamegraph-26636.094.100.svg,
> flamegraph-28066.098.singlecell.svg, flamegraph-28767.098.100.svg,
> flamegraph-31647.master.100.svg, flamegraph-9466.094.singlecell.svg,
> m.test.patch, region_lock.png, testincrement.094.patch,
> testincrement.098.patch, testincrement.master.patch
>
>
> 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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