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*: prevent cursor read from being cancelled by GC (#39950) #39990

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ti-chi-bot
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This is an automated cherry-pick of #39950

Signed-off-by: zyguan zhongyangguan@gmail.com

What problem does this PR solve?

Issue Number: close #39447

Problem Summary:

Cursor read might be cancelled by GC since min-start-ts is calculated by min([s.ProcessInfo.CurTxnStartTS for s in all sessions]) however the CurTxnStartTS will be reset once fetch returned.

What is changed and how it works?

  1. Let each session hold a list of pretected timestamps.
  2. Let session manager calculate the min-start-ts (considering protected timestamps).
  3. When start to do cursor read, hold the start-ts until the result set gets close.

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

Please refer to Release Notes Language Style Guide to write a quality release note.

None

Signed-off-by: ti-chi-bot <ti-community-prow-bot@tidb.io>
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ti-chi-bot commented Dec 16, 2022

[REVIEW NOTIFICATION]

This pull request has been approved by:

  • cfzjywxk
  • ekexium

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 release-note-none Denotes a PR that doesn't merit a release note. do-not-merge/cherry-pick-not-approved size/XL Denotes a PR that changes 500-999 lines, ignoring generated files. type/cherry-pick-for-release-6.5 This PR is cherry-picked to release-6.5 from a source PR. labels Dec 16, 2022
@VelocityLight VelocityLight added cherry-pick-approved Cherry pick PR approved by release team. and removed do-not-merge/cherry-pick-not-approved labels Jan 16, 2023
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@zyguan
Need help to resolve the conflicts.

Signed-off-by: zyguan <zhongyangguan@gmail.com>
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@zyguan @ekexium @you06
Need approvements.

@ti-chi-bot ti-chi-bot added the status/LGT1 Indicates that a PR has LGTM 1. label Feb 13, 2023
@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 Feb 13, 2023
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/merge

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

Commit hash: e14b953

@ti-chi-bot ti-chi-bot added the status/can-merge Indicates a PR has been approved by a committer. label Feb 13, 2023
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/retest

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@hawkingrei
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/retest

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zyguan commented Feb 16, 2023

/merge

@zyguan
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zyguan commented Feb 16, 2023

/retest

3 similar comments
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zyguan commented Feb 17, 2023

/retest

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zyguan commented Feb 17, 2023

/retest

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zyguan commented Feb 17, 2023

/retest

@ti-chi-bot ti-chi-bot merged commit 155e3ea into pingcap:release-6.5 Feb 17, 2023
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6 participants