logservice,event: stop capturing tidb_ddl_history

[wlwilliamx]

What problem does this PR solve?

Issue Number: close #2272

What is changed and how it works?

This PR removes TiCDC's remaining upstream capture path for tidb_ddl_history.

• stop subscribing to tidb_ddl_history in the schema-store DDL fetcher
• stop initializing tidb_ddl_history metadata for DDL parsing
• parse DDL jobs only from tidb_ddl_job
• accept only JobStateDone jobs from tidb_ddl_job and drop the old JobStateSynced compatibility path
• add regression tests for DDL span subscription and job parsing behavior

This aligns TiCDC with the TiDB v8.3+ / v8.5 GA behavior targeted by issue #2272, where CREATE TABLE no longer requires tidb_ddl_history capture.

Check List

Tests

• Unit test
• Manual test

Questions

Will it cause performance regression or break compatibility?

No performance regression is expected.

This intentionally drops compatibility with older TiDB behavior where CREATE TABLE could be emitted only through tidb_ddl_history. That is the behavior cleanup requested by issue #2272.

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

No.

Release note

TiCDC no longer captures DDLs from `tidb_ddl_history` and relies on `tidb_ddl_job` for accelerated table creation.

Summary by CodeRabbit

• Refactor
  • Simplified DDL job handling to use only the main DDL job table and removed legacy history-table handling; parsing now focuses on completed jobs for a normalized DDL lifecycle.
• Tests
  • Added unit tests validating the consolidated span discovery and the updated job-parsing behavior for various DDL job states.

[ti-chi-bot]

Skipping CI for Draft Pull Request.
If you want CI signal for your change, please convert it to an actual PR.
You can still manually trigger a test run with /test all

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: a6e5c789-dd70-41c5-8c88-e3312cba40d4

📥 Commits

Reviewing files that changed from the base of the PR and between 4e95396 and 7a960ab.

📒 Files selected for processing (1)

• logservice/schemastore/ddl_job_fetcher_test.go

🚧 Files skipped from review as they are similar to previous changes (1)

• logservice/schemastore/ddl_job_fetcher_test.go

---

📝 Walkthrough

Walkthrough

This PR removes capture and parsing logic for tidb_ddl_history, consolidating DDL job discovery and parsing to tidb_ddl_job only; constants, metadata fields, and conditional history-path logic were deleted and tests updated to assert the new single-span behavior.

Changes

Cohort / File(s)	Summary
DDL Job Fetcher logservice/schemastore/ddl_job_fetcher.go, logservice/schemastore/ddl_job_fetcher_test.go	Dropped metadef dependency and history-table initialization. getAllDDLSpan now returns a single heartbeatpb.TableSpan for common.JobTableID. Added TestGetAllDDLSpan to validate one-span result.
Event Mounter pkg/common/event/mounter.go, pkg/common/event/mounter_test.go	Removed DDLHistoryTable and JobMetaColumnIDinHistoryTable from DDLTableInfo. Simplified ParseDDLJob/parseJob (removed fromHistoryTable path) to only accept jobs where job.IsDone(). Added tests (TestParseJobFromDDLJob) covering Done/state behaviors.
Span Operations pkg/common/span_op.go	Removed exported JobHistoryID constant that referenced tidb_ddl_history.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Suggested labels

size/XL

Suggested reviewers

• lidezhu
• hongyunyan

Poem

🐰 I hopped through tables, sniffed the past,

Found one that holds the jobs at last.
No history chase, one span to see,
Clean and brisk — a simple key.
🥕 Hop, commit, and off I flee!

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 28.57% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly and concisely summarizes the main change: stopping capture of tidb_ddl_history, which is the primary objective of this PR.
Description check	✅ Passed	The PR description covers the required sections: issue reference (#2272), detailed explanation of changes, test coverage, compatibility considerations, and a release note.
Linked Issues check	✅ Passed	The PR successfully removes tidb_ddl_history capture across multiple components: stops subscribing in DDL fetcher, removes metadata initialization, parses only from tidb_ddl_job, and adds regression tests, fully addressing issue #2272.
Out of Scope Changes check	✅ Passed	All changes are directly scoped to removing tidb_ddl_history capture paths from DDL fetching and parsing logic, with supporting test additions, with no extraneous modifications.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

Warning

There were issues while running some tools. Please review the errors and either fix the tool's configuration or disable the tool if it's a critical failure.

🔧 golangci-lint (2.11.4)

Command failed

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[gemini-code-assist]

Code Review

This pull request simplifies DDL job fetching by removing support for the tidb_ddl_history table, as TiDB v8.3+ now emits all DDL jobs through tidb_ddl_job. The changes refactor the fetcher and mounter to subscribe to and parse only the job table. Feedback indicates that using job.IsDone() is incorrect because it accepts JobStateSynced jobs, which contradicts the goal of only accepting JobStateDone and would cause the new compatibility tests to fail.

[gemini-code-assist]

The use of job.IsDone() here contradicts the PR description ("accept only JobStateDone jobs") and the new test case ignores synced create table compatibility jobs in mounter_test.go. Since IsDone() returns true for JobStateSynced, this implementation will still accept jobs in the Synced state, causing the test to fail. To align with the goal of dropping the JobStateSynced compatibility path, you should check for model.JobStateDone explicitly.

Suggested change

	if !job.IsDone() {
	return nil, nil
	}
	if job.State != model.JobStateDone {
	return nil, nil
	}

[wlwilliamx]

/test all

[wlwilliamx]

/retest

[wlwilliamx]

/retest

[wlwilliamx]

/test pull-cdc-kafka-integration-light

[wlwilliamx]

/test pull-cdc-mysql-integration-light

[wlwilliamx]

/retest

[wlwilliamx]

/retest

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: hongyunyan, wk989898

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Needs approval from an approver in each of these files:

• OWNERS [hongyunyan,wk989898]

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[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2026-04-13 04:23:04.482133649 +0000 UTC m=+1362189.687493705: ☑️ agreed by wk989898.
• 2026-04-14 16:38:03.004131067 +0000 UTC m=+1492688.209491124: ☑️ agreed by hongyunyan.

[wlwilliamx]

/retest

[ti-chi-bot]

@wlwilliamx: The following tests failed, say /retest to rerun all failed tests or /retest-required to rerun all mandatory failed tests:

Test name	Commit	Details	Required	Rerun command
pull-cdc-mysql-integration-heavy	4e95396	link	unknown	/test pull-cdc-mysql-integration-heavy
pull-unit-test-next-gen	4e95396	link	unknown	/test pull-unit-test-next-gen

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[ti-chi-bot]

In response to a cherrypick label: new pull request created to branch release-8.5: #4905.
But this PR has conflicts, please resolve them!