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util, executor: use a individual rowContainer for each probeWorker in HashJoinExec #27577

Merged
merged 5 commits into from
Sep 7, 2021
Merged

util, executor: use a individual rowContainer for each probeWorker in HashJoinExec #27577

merged 5 commits into from
Sep 7, 2021

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XuHuaiyu
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What problem does this PR solve?

Issue Number: close #27576

Problem Summary:

What is changed and how it works?

Proposal: xxx

What's Changed:
Use an individual rowContainer for each probeWorker in HashJoinExec to eliminate the contention when accessing rowContainer.Mutex.

How it Works:

Check List

Tests

  • Unit test
  • Integration test
  • Manual test (add detailed scripts or steps below)
tidb_executor_concurrency lantency
2 20.78s
4 13.93s
8 8.18s
16 5.56s
32 3.42s

截屏2021-08-25 下午3 32 35

Side effects

N/A

Documentation

N/A

Release note 

Improve the query performance for HashJoin.

@XuHuaiyu XuHuaiyu added type/enhancement The issue or PR belongs to an enhancement. sig/execution SIG execution component/executor labels Aug 25, 2021
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ti-chi-bot commented Aug 25, 2021 •
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[REVIEW NOTIFICATION]

This pull request has been approved by:

  • guo-shaoge
  • wshwsh12

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@ti-chi-bot ti-chi-bot added release-note Denotes a PR that will be considered when it comes time to generate release notes. size/L Denotes a PR that changes 100-499 lines, ignoring generated files. labels Aug 25, 2021
@XuHuaiyu XuHuaiyu force-pushed the refine_rowcontainer_2 branch 3 times, most recently from 3377cae to 6cd3123 Compare August 31, 2021 09:56
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XuHuaiyu commented Sep 1, 2021

The failed cases: TestShowGrantsForCurrentUserUsingRole and TestIterator have nothing to do with this commit.

wshwsh12
wshwsh12 reviewed Sep 1, 2021
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util/chunk/row_container.go Outdated
Comment on lines 48 to 49
// spillError stores the error when spilling.
spillError error
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Should we put spillError into rowContainerRecord? When there is a spilling error, all goroutions can observe the error and exit.

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spillError is of the interface type, it seems we do not need to put it in rowContainerRecord

executor/hash_table.go Show resolved Hide resolved
guo-shaoge
guo-shaoge reviewed Sep 6, 2021
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executor/hash_table.go
@@ -115,7 +125,7 @@ func (c *hashRowContainer) GetMatchedRowsAndPtrs(probeKey uint64, probeRow chunk
return
}
if !ok {
c.stat.probeCollision++
atomic.AddInt64(&c.stat.probeCollision, 1)
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Guess this can be a new hotspot. Myabe we can let user control the HashTalbe's bucket size to fix.

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Actually, the collision should be small probability event

@ti-chi-bot ti-chi-bot added the status/LGT1 Indicates that a PR has LGTM 1. label Sep 6, 2021
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/run-common-test
/run-integration-copr-test
/run-integration-common-test

wshwsh12
wshwsh12 approved these changes Sep 6, 2021
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LGTM

@ti-chi-bot ti-chi-bot added status/LGT2 Indicates that a PR has LGTM 2. and removed status/LGT1 Indicates that a PR has LGTM 1. labels Sep 6, 2021
@ti-chi-bot ti-chi-bot added size/XL Denotes a PR that changes 500-999 lines, ignoring generated files. and removed size/L Denotes a PR that changes 100-499 lines, ignoring generated files. labels Sep 7, 2021
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XuHuaiyu commented Sep 7, 2021

/merge

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This pull request has been accepted and is ready to merge.

Commit hash: 2c15078

@ti-chi-bot ti-chi-bot added the status/can-merge Indicates a PR has been approved by a committer. label Sep 7, 2021
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@XuHuaiyu: Your PR was out of date, I have automatically updated it for you.

At the same time I will also trigger all tests for you:

/run-all-tests

If the CI test fails, you just re-trigger the test that failed and the bot will merge the PR for you after the CI passes.

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@ti-chi-bot ti-chi-bot merged commit 6b9d0c5 into pingcap:master Sep 7, 2021
@jingshanglu jingshanglu mentioned this pull request Sep 8, 2021
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@ichn-hu ichn-hu mentioned this pull request Sep 8, 2021
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@wshwsh12 wshwsh12 wshwsh12 approved these changes

@guo-shaoge guo-shaoge guo-shaoge approved these changes

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Successfully merging this pull request may close these issues.

bottleneck when accessing rowContainer.m.Mutex in HashJoinExec
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@XuHuaiyu @ti-chi-bot @guo-shaoge @wshwsh12