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https://issues.apache.org/jira/browse/HBASE-14460?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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stack updated HBASE-14460:
--------------------------
    Release Note: Regression addressed narrowly on branch-1 (1.0.3+, 1.1.3+, 
and 1.2.0). You need to set a  "hbase.increment.fast.but.narrow.consistency" 
and rolling restart to enable a 'fast path' for increments only (appends, 
checkAndPut, etc., are not address in branch-1). See the sub-task release notes 
for more detail. On master branch, a more substantial change is done changing 
write path so all check-and-put type operations -- i.e. increment, append, 
checkAnd*, etc. -- have the regression addressed.

> [Perf Regression] Merge of MVCC and SequenceId (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, 
> 1.0.80.flamegraph-7932.svg, 14460.txt, 14460.v0.branch-1.0.patch, 
> 98.80.flamegraph-11428.svg, HBASE-14460-discussion.patch, client.test.patch, 
> 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, 
> hack.flamegraph-16593.svg, hack.uncommitted.patch, 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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