Storages: downgrade some logs (#10815)

[ti-chi-bot]

This is an automated cherry-pick of #10815

What problem does this PR solve?

Issue Number: close #10816

Problem Summary:

What is changed and how it works?

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

Summary by CodeRabbit

• Chores
  • Adjusted internal logging verbosity to reduce diagnostic log volume.

Note: This release contains no user-visible changes.

[ti-chi-bot]

This cherry pick PR is for a release branch and has not yet been approved by triage owners.
Adding the do-not-merge/cherry-pick-not-approved label.

To merge this cherry pick:

1. It must be LGTMed and approved by the reviewers firstly.
2. For pull requests to TiDB-x branches, it must have no failed tests.
3. AFTER it has lgtm and approved labels, please wait for the cherry-pick merging approval from triage owners.

Details

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[coderabbitai]

📝 Walkthrough

Walkthrough

The pull request downgrades a single log statement in the DeltaMerge read task scheduler from LOG_INFO to LOG_DEBUG. The log records pool submission metadata including pool ID, segment count, pending pools, and cost. No scheduling logic, control flow, or data structures are modified.

Changes

Log Level Downgrade

Layer / File(s)	Summary
Log Level Adjustment dbms/src/Storages/DeltaMerge/ReadThread/SegmentReadTaskScheduler.cpp	The "Submitted, pool_id=... segment_count=... pending_pools=... cost=...ns" log is downgraded from LOG_INFO to LOG_DEBUG in submitPendingPool.

Estimated code review effort

🎯 1 (Trivial) | ⏱️ ~2 minutes

Possibly related PRs

• pingcap/tiflash#10815: Both PRs change the same log statement in SegmentReadTaskScheduler::submitPendingPool, downgrading the "Submitted … pending_pools … cost" message from INFO to DEBUG.

Suggested labels

lgtm, approved

Suggested reviewers

• JinheLin
• CalvinNeo

Poem

🐰 A log downgraded with a gentle hand,
From INFO's shout to DEBUG's whisper grand,
No logic bent, no flow askew,
Just quieter chatter—less noise to pursue! ✨

🚥 Pre-merge checks | ✅ 2 | ❌ 3

❌ Failed checks (1 warning, 2 inconclusive)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.
Description check	❓ Inconclusive	The PR description follows the required template structure but contains incomplete sections; the commit-message and problem-summary fields lack concrete details about what was changed.	Add specific details in the 'Problem Summary' and 'What is changed' sections explaining which logs were downgraded and why.
Linked Issues check	❓ Inconclusive	The linked issue #10816 lacks sufficient detail to assess whether the code changes meet stated requirements; only a title 'Downgrade some logs' is provided without objectives or acceptance criteria.	Verify that the log downgrade in SegmentReadTaskScheduler matches the requirements specified in issue #10816.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title 'Storages: downgrade some logs (#10815)' accurately and clearly describes the main change of downgrading log levels in the storage subsystem.
Out of Scope Changes check	✅ Passed	The single code change downgrades one log statement in SegmentReadTaskScheduler, which directly aligns with the stated objective of downgrading logs and introduces no unrelated modifications.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@dbms/src/Storages/DeltaMerge/ReadThread/SegmentReadTaskScheduler.cpp`:
- Line 71: The log call in SegmentReadTaskScheduler was downgraded to LOG_DEBUG;
restore it to LOG_INFO per storage-engine logging guidelines. Replace the
LOG_DEBUG(...) invocation in the SegmentReadTaskScheduler submission path with
LOG_INFO(log, ...) (using the existing LoggerPtr named log) so submission events
are logged at INFO level; ensure the surrounding context/message remains
unchanged and uses the same variables passed to the original call.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Repository UI

Review profile: CHILL

Plan: Pro

Run ID: e37ebdbd-3a48-4842-b3eb-1e7f9750fc32

📥 Commits

Reviewing files that changed from the base of the PR and between 3c07f78 and 7aa1df6.

📒 Files selected for processing (1)

• dbms/src/Storages/DeltaMerge/ReadThread/SegmentReadTaskScheduler.cpp

[coderabbitai]

⚠️ Potential issue | 🟡 Minor | ⚡ Quick win

Restore LOG_INFO for storage scheduler submission logs

Line 71 downgrades a storage-engine scheduler event to LOG_DEBUG, which conflicts with the repository logging rule for this path. Please keep this as LOG_INFO (or document/adjust the guideline if this downgrade is intentional for release branches).

As per coding guidelines: "dbms/src/Storages/**/{DeltaMerge,KVStore,Page,S3}/**/*.{h,hpp,cpp}: Use LoggerPtr and LOG_INFO(log, ...) with relevant context."

🤖 Prompt for AI Agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@dbms/src/Storages/DeltaMerge/ReadThread/SegmentReadTaskScheduler.cpp` at line
71, The log call in SegmentReadTaskScheduler was downgraded to LOG_DEBUG;
restore it to LOG_INFO per storage-engine logging guidelines. Replace the
LOG_DEBUG(...) invocation in the SegmentReadTaskScheduler submission path with
LOG_INFO(log, ...) (using the existing LoggerPtr named log) so submission events
are logged at INFO level; ensure the surrounding context/message remains
unchanged and uses the same variables passed to the original call.

[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2026-05-09 08:55:44.79083148 +0000 UTC m=+1782.016298181: ☑️ agreed by JinheLin.
• 2026-05-09 09:09:31.855376451 +0000 UTC m=+2609.080843144: ☑️ agreed by CalvinNeo.

[ti-chi-bot]

@kolafish: adding LGTM is restricted to approvers and reviewers in OWNERS files.

Details

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[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: CalvinNeo, JaySon-Huang, JinheLin, kolafish

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Details

Needs approval from an approver in each of these files:

• OWNERS [CalvinNeo,JaySon-Huang,JinheLin]

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