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table/tables: fix a corner case of renew lease operation on cached table #32643

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merged 11 commits into from
Mar 15, 2022
Merged

table/tables: fix a corner case of renew lease operation on cached table #32643

merged 11 commits into from
Mar 15, 2022

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tiancaiamao
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@tiancaiamao tiancaiamao commented Feb 25, 2022 •
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What problem does this PR solve?

Issue Number: close #32642

Problem Summary:

What is changed and how it works?

Handle the bug that after Read Locked -> Write -> Read Locked state changes, the renew lease operation success mistakenly.
Now I check oldLocalLease != remoteLease to see whether there is another intermediate state change, and prevent the ABA issue.
This change can also reduce the conflict when there are several tidb instances handling renew lease simultaneously.

Check List

Tests

  • Unit test
  • Integration test
  • Manual test (add detailed scripts or steps below)
  • No code

Side effects

  • Performance regression: Consumes more CPU
  • Performance regression: Consumes more Memory
  • Breaking backward compatibility

Documentation

  • Affects user behaviors
  • Contains syntax changes
  • Contains variable changes
  • Contains experimental features
  • Changes MySQL compatibility

Release note

None

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ti-chi-bot commented Feb 25, 2022 •
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[REVIEW NOTIFICATION]

This pull request has been approved by:

  • lcwangchao
  • tangenta

To complete the pull request process, please ask the reviewers in the list to review by filling /cc @reviewer in the comment.
After your PR has acquired the required number of LGTMs, you can assign this pull request to the committer in the list by filling /assign @committer in the comment to help you merge this pull request.

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@ti-chi-bot ti-chi-bot added do-not-merge/needs-triage-completed release-note-none Denotes a PR that doesn't merit a release note. size/XL Denotes a PR that changes 500-999 lines, ignoring generated files. labels Feb 25, 2022
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sre-bot commented Feb 25, 2022 •
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Code Coverage Details: https://codecov.io/github/pingcap/tidb/commit/c5dd83eb758529b5421d1356334b558d32ffeae7

This was referenced Feb 28, 2022
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tiancaiamao added a commit to tiancaiamao/tidb that referenced this pull request Mar 1, 2022
@tiancaiamao
table/tables: fix a corner case of renew lease operation on cached
f482749 
table (pingcap#32643)

close pingcap#32642
@ti-chi-bot ti-chi-bot added size/L Denotes a PR that changes 100-499 lines, ignoring generated files. and removed do-not-merge/needs-triage-completed size/XL Denotes a PR that changes 500-999 lines, ignoring generated files. labels Mar 1, 2022
tiancaiamao
tiancaiamao commented Mar 1, 2022
View reviewed changes
table/tables/cache.go
@@ -52,7 +43,6 @@ type cachedTable struct {
handle StateRemote
totalSize int64

lockingForRead tokenLimit
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Before removing this line, the LockForRead and RenewLease operation may happen at the same time ... but they share the same StateRemote handle instance for executing SQL.
That would cause DATA RACE

@ti-chi-bot ti-chi-bot added the status/LGT1 Indicates that a PR has LGTM 1. label Mar 2, 2022
tangenta
tangenta reviewed Mar 15, 2022
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@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 Mar 15, 2022
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/merge

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

Commit hash: 97171f8

@ti-chi-bot ti-chi-bot added the status/can-merge Indicates a PR has been approved by a committer. label Mar 15, 2022
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/run-unit-test

@ti-chi-bot ti-chi-bot merged commit ecffe84 into pingcap:master Mar 15, 2022
@tiancaiamao tiancaiamao deleted the renew-lease branch March 15, 2022 10:06
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@tangenta tangenta tangenta approved these changes

@lcwangchao lcwangchao lcwangchao approved these changes

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A corner case of renew lease operation on cached table
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