dm/syncer: advance checkpoint on rotate events (#12405) by ti-chi-bot · Pull Request #12525 · pingcap/tiflow

ti-chi-bot · 2026-02-13T02:42:44Z

This is an automated cherry-pick of #12405

What problem does this PR solve?

Issue Number: close #12339

What is changed and how it works?

Advance global checkpoint position based on end location of rotate events.

Check List

Tests

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

Questions

Will it cause performance regression or break compatibility?

Do you need to update user documentation, design documentation or monitoring documentation?

Release note

Please refer to [Release Notes Language Style Guide](https://pingcap.github.io/tidb-dev-guide/contribute-to-tidb/release-notes-style-guide.html) to write a quality release note.

If you don't think this PR needs a release note then fill it with `None`.

gemini-code-assist · 2026-02-13T02:42:57Z

Summary of Changes

Hello @ti-chi-bot, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request addresses an issue where the global checkpoint was not being consistently updated during binlog rotate events. By explicitly saving the global checkpoint position when a non-fake rotate event occurs, the change ensures more accurate and reliable progress tracking, which is crucial for data consistency and disaster recovery scenarios. The addition of a dedicated unit test further validates this critical behavior.

Highlights

Global Checkpoint Advancement: The system now correctly advances the global checkpoint position based on the end location of non-fake rotate events, ensuring that the checkpoint accurately reflects the processed binlog position.
Unit Test Coverage: A new unit test has been added to specifically verify that the global checkpoint is updated as expected when a rotate event is handled, improving the robustness of the checkpointing mechanism.

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Changelog

dm/syncer/syncer.go
- Modified handleRotateEvent to save the global checkpoint using s.saveGlobalPoint(ec.endLocation) when processing non-fake rotate events.
dm/syncer/syncer_test.go
- Added TestHandleRotateEventUpdatesGlobalCheckpoint to test the correct advancement of the global checkpoint during rotate events.

Activity

This pull request is an automated cherry-pick of dm/syncer: advance checkpoint on rotate events #12405.

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Code Review

The pull request correctly implements the advancement of the global checkpoint position when a rotate event is received. This is a valuable improvement that ensures the syncer's progress is tracked even during periods of inactivity in the binlog stream (e.g., when rotating through empty or filtered binlog files). The implementation correctly handles both normal and sharding resync modes and appropriately skips fake rotate events. A unit test has been added to verify the core functionality.

gemini-code-assist · 2026-02-13T02:49:36Z

dm/syncer/syncer.go

+		if !utils.IsFakeRotateEvent(ec.header) {
+			s.saveGlobalPoint(ec.endLocation)
+		}


The logic to save the global point on a non-fake rotate event is duplicated here and at the end of the function. While correct, it could be refactored for better maintainability. However, since this is a cherry-pick and the logic is sound, this is a minor observation.

OliverS929 · 2026-02-13T04:25:23Z

/retest

codecov · 2026-02-13T04:36:57Z

Codecov Report

❌ Patch coverage is 50.00000% with 3 lines in your changes missing coverage. Please review.
⚠️ Please upload report for BASE (release-8.5@f18090a). Learn more about missing BASE report.

Additional details and impacted files

Components	Coverage Δ
cdc	`57.8263% <0.0000%> (?)`
dm	`48.7081% <0.0000%> (?)`
engine	`50.7332% <0.0000%> (?)`

Flag	Coverage Δ
unit	`53.4431% <50.0000%> (?)`

Flags with carried forward coverage won't be shown. Click here to find out more.

@@               Coverage Diff                @@
##             release-8.5     #12525   +/-   ##
================================================
  Coverage               ?   53.4431%           
================================================
  Files                  ?       1045           
  Lines                  ?     137142           
  Branches               ?          0           
================================================
  Hits                   ?      73293           
  Misses                 ?      58394           
  Partials               ?       5455

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Benjamin2037

LGTM

OliverS929 · 2026-02-27T07:38:54Z

/retest

OliverS929 · 2026-03-04T09:09:44Z

/retest

OliverS929 · 2026-03-04T10:03:46Z

/retest

OliverS929 · 2026-03-04T23:40:59Z

/retest

OliverS929 · 2026-03-05T02:44:18Z

/retest

ti-chi-bot · 2026-03-05T08:37:17Z

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: 3AceShowHand, Benjamin2037, D3Hunter

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Details

Needs approval from an approver in each of these files:

~~OWNERS~~ [3AceShowHand,Benjamin2037,D3Hunter]
~~dm/OWNERS~~ [Benjamin2037,D3Hunter]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

3AceShowHand · 2026-03-05T09:52:55Z

/retest

OliverS929 · 2026-03-05T10:54:39Z

/retest

OliverS929 · 2026-03-05T11:24:42Z

/retest

OliverS929 · 2026-03-05T14:15:22Z

/retest

OliverS929 · 2026-03-05T15:26:27Z

/retest

OliverS929 · 2026-03-05T15:46:46Z

/retest

OliverS929 · 2026-03-05T16:35:06Z

/retest

3AceShowHand · 2026-03-06T02:46:16Z

/test all

… algorithm (pingcap#12525) Add a new `checksum-algorithm` configuration flag to sync-diff-inspector to support FIPS-compliant environments where MD5 is disabled. Supported options: "md5" (default) and "sha256". Cherry-picked from pingcap/tidb-tools#886 Close pingcap/tidb-tools#885 Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

OliverS929 · 2026-03-06T07:13:24Z

/retest

OliverS929 · 2026-03-06T09:11:31Z

/retest

OliverS929 · 2026-03-06T11:16:40Z

/retest

OliverS929 · 2026-03-07T01:58:36Z

/retest

OliverS929 · 2026-03-07T03:17:19Z

/retest

OliverS929 added 2 commits February 13, 2026 02:42

dm/syncer: advance checkpoint on rotate events

d06af5d

Don't sync on fake rotate event.

e0ae12c

ti-chi-bot mentioned this pull request Feb 13, 2026

dm/syncer: advance checkpoint on rotate events #12405

Merged

1 task

ti-chi-bot bot added the do-not-merge/cherry-pick-not-approved label Feb 13, 2026

ti-chi-bot assigned OliverS929 Feb 13, 2026

gemini-code-assist bot reviewed Feb 13, 2026

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D3Hunter approved these changes Feb 13, 2026

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ti-chi-bot bot added the approved label Feb 13, 2026

Benjamin2037 approved these changes Feb 13, 2026

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ti-chi-bot bot added cherry-pick-approved Cherry pick PR approved by release team. and removed do-not-merge/cherry-pick-not-approved labels Feb 14, 2026

Fix static.

68f656e

fix cdc unstable ut.

8cedd8d

3AceShowHand approved these changes Mar 5, 2026

View reviewed changes

fix unstable test

8b92e7a

ti-chi-bot bot merged commit aa5c32c into pingcap:release-8.5 Mar 7, 2026
25 of 29 checks passed

ti-chi-bot bot deleted the cherry-pick-12405-to-release-8.5 branch March 7, 2026 03:59

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ti-chi-bot commented Feb 13, 2026

What problem does this PR solve?

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