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https://issues.apache.org/jira/browse/HBASE-15453?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Lars Hofhansl updated HBASE-15453:
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Attachment: 15453-0.98.txt
Here's the patch with test.
[~apurtell], [~stack], and anybody else, if you guys have some time, could you
apply this patch and run TestScanFilterPerformance?
Then undo the changes to StoreScanner and ReversedStoreScanner and run the test
again.
The test does some warm up, then runs the perf test 10 times and calculates
mean and standard deviation.
> Considering reverting HBASE-10015 - reinstance synchronized in StoreScanner
> ---------------------------------------------------------------------------
>
> Key: HBASE-15453
> URL: https://issues.apache.org/jira/browse/HBASE-15453
> Project: HBase
> Issue Type: Bug
> Reporter: Lars Hofhansl
> Attachments: 15453-0.98.txt
>
>
> In HBASE-10015 back then I found that intrinsic locks (synchronized) in
> StoreScanner are slower that explicit locks.
> I was surprised by this. To make sure I added a simple perf test and many
> folks ran it on their machines. All found that explicit locks were faster.
> Now... I just ran that test again. On the latest JDK8 I find that now the
> intrinsic locks are significantly faster:
> Explicit locks:
> 10 runs mean:2223.6 sigma:72.29412147609237
> Intrinsic locks:
> 10 runs mean:1865.3 sigma:32.63755505548784
> I confirmed the same with timing some Phoenix scans. We can save a bunch of
> time by changing this back
> Arrghhh... So maybe it's time to revert this now...?
> (Note that in trunk due to [~ram_krish]'s work, we do not lock in
> StoreScanner anymore)
> I'll attach the perf test and a patch that changes lock to synchronized, if
> some folks could run this on 0.98, that'd be great.
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