infoschema: fix information_schema.tikv_region_status for nextgen (#67444)

[ti-chi-bot]

This is an automated cherry-pick of #67444

What problem does this PR solve?

Issue Number: close #67442, close #67441

Problem Summary:

1. The information_schema.tikv_region_status usually includes all regions in all keyspaces.
2. The WHERE table_id = xxx condition doesn't include indexes.

What changed and how does it work?

Check List

Tests

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

  • I checked and no code files have been changed.

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

Summary by CodeRabbit

Release Notes

• Tests

  • Enhanced information_schema.tikv_region_status test coverage for region splitting and index regions.
  • Added keyspace isolation verification tests to prevent cross-keyspace region data contamination.

• Chores

  • Refactored region retrieval implementation for improved efficiency.
  • Updated build dependencies.

[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

This PR addresses two bugs in information_schema.tikv_region_status: expanding key-range queries to include index regions when filtering by table ID, and isolating region data to the current keyspace to prevent information leakage. A new helper method retrieves all regions for the store with full key-range coverage, and region-filtering logic is refactored to use this method while enforcing keyspace boundaries.

Changes

Cohort / File(s)	Summary
Build Configuration pkg/executor/BUILD.bazel, tests/realtikvtest/sessiontest/BUILD.bazel	Added Bazel dependency //pkg/ddl/placement to executor targets; increased sessiontest shard count from 16 to 17 and added //pkg/config/kerneltype and //pkg/keyspace dependencies.
Helper Infrastructure pkg/store/helper/helper.go	Added new exported method GetRegions(ctx context.Context) that retrieves all regions for the current store by querying PD with a full-store key-range, encapsulating PD client acquisition and key-range encoding logic.
Region Query Logic pkg/executor/infoschema_reader.go, pkg/executor/memtable_reader.go	Refactored callers to use the new helper GetRegions() method instead of directly accessing PD HTTP client; expanded key-range query in getRegionsInfoForSingleTable from table handle ranges to full table prefix ranges to include both record and index regions.
Test Infrastructure & Coverage pkg/executor/infoschema_cluster_table_test.go, tests/realtikvtest/sessiontest/infoschema_test.go	Extended mocked PD server with region-key lookup, placement rule group, and config endpoints; refactored region mock responses to be parameterized by key ranges; updated TestNextGenTiKVRegionStatus to verify region counts match across table and index splits; added TestNextGenTiKVRegionStatusDoesNotMixOtherKeyspaces to verify keyspace isolation.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~25 minutes

Possibly related PRs

• pingcap/tidb#67444 — Implements identical core changes (Helper.GetRegions, executor refactoring, PD mock updates) addressing the same region-status filtering issues.
• pingcap/tidb#66194 — Modifies helper and executor region key-range handling and PD client interactions.

Suggested labels

cherry-pick-approved, ok-to-test

Suggested reviewers

• tangenta
• tiancaiamao

Poem

🐰 A helper so clever, it gathers them all,
Index and record, no regions fall through,
Keyspaces stay pure, no cross-table sprawl,
The info schema view now speaks truth so true! 📊✨

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

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.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly and specifically describes the main fix: addressing issues with information_schema.tikv_region_status for nextgen, directly matching the PR's core objective.
Description check	✅ Passed	The description includes issue numbers (#67442, #67441), problem summary addressing both index region inclusion and keyspace isolation, checked test boxes (unit and integration), and follows the required template structure.
Linked Issues check	✅ Passed	Code changes comprehensively address both linked issues: #67441 (keyspace isolation via GetRegions and boundary detection) and #67442 (index region inclusion via expanded key-range queries).
Out of Scope Changes check	✅ Passed	All changes are directly related to fixing information_schema.tikv_region_status: PD HTTP client refactoring, region key-range expansion for index coverage, helper method additions, test enhancements, and associated Bazel build configuration updates.

_{✏️ 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]

Caution

Some comments are outside the diff and can’t be posted inline due to platform limitations.

⚠️ Outside diff range comments (1)

pkg/executor/memtable_reader.go (1)

919-924: ⚠️ Potential issue | 🟠 Major

Keep filtered peer lookups on the same keyspace boundary.

The no-filter path is now keyspace-scoped, but the StoreIDs / RegionIDs branches below still use global PD lookups and never re-check the returned key range. In nextgen, WHERE store_id = ... or WHERE region_id = ... can still expose peer rows from other keyspaces, so visibility becomes filter-dependent. Filter those PD results against tikvStore.GetCodec().EncodeRegionRange(nil, nil) before packing rows.

🤖 Prompt for AI Agents

Verify each finding against the current code and only fix it if needed.

In `@pkg/executor/memtable_reader.go` around lines 919 - 924, The StoreIDs and
RegionIDs branches (code paths checking e.extractor.StoreIDs and
e.extractor.RegionIDs and calling tikvHelper.GetStores/GetRegions) perform
global PD lookups and must be filtered to the current keyspace before calling
e.packTiKVRegionPeersRows; update those branches to filter the returned
stores/regions by checking each entry’s region key range against the current
keyspace bounds produced by tikvStore.GetCodec().EncodeRegionRange(nil, nil)
(i.e., compute the encoded start/end for the keyspace and drop any store/region
whose region range falls outside those bounds) so that packTiKVRegionPeersRows
only receives peers within the same keyspace.

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Outside diff comments:
In `@pkg/executor/memtable_reader.go`:
- Around line 919-924: The StoreIDs and RegionIDs branches (code paths checking
e.extractor.StoreIDs and e.extractor.RegionIDs and calling
tikvHelper.GetStores/GetRegions) perform global PD lookups and must be filtered
to the current keyspace before calling e.packTiKVRegionPeersRows; update those
branches to filter the returned stores/regions by checking each entry’s region
key range against the current keyspace bounds produced by
tikvStore.GetCodec().EncodeRegionRange(nil, nil) (i.e., compute the encoded
start/end for the keyspace and drop any store/region whose region range falls
outside those bounds) so that packTiKVRegionPeersRows only receives peers within
the same keyspace.

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Repository UI

Review profile: CHILL

Plan: Pro

Run ID: d893763f-aa4c-41a1-a865-8f562333595c

📥 Commits

Reviewing files that changed from the base of the PR and between 5ec8168 and 717cd73.

📒 Files selected for processing (7)

• pkg/executor/BUILD.bazel
• pkg/executor/infoschema_cluster_table_test.go
• pkg/executor/infoschema_reader.go
• pkg/executor/memtable_reader.go
• pkg/store/helper/helper.go
• tests/realtikvtest/sessiontest/BUILD.bazel
• tests/realtikvtest/sessiontest/infoschema_test.go

[YangKeao]

The test will pass after #67505 is merged.

[YangKeao]

/hold

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: tangenta, tiancaiamao

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 [tangenta,tiancaiamao]

Approvers can indicate their approval by writing /approve in a comment
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[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2026-04-02 08:09:11.548292899 +0000 UTC m=+425356.753652956: ☑️ agreed by tiancaiamao.
• 2026-04-02 08:11:12.62184537 +0000 UTC m=+425477.827205427: ☑️ agreed by tangenta.

[YangKeao]

/retest

[codecov]

Codecov Report

❌ Patch coverage is 56.25000% with 7 lines in your changes missing coverage. Please review.
⚠️ Please upload report for BASE (release-nextgen-20251011@5ec8168). Learn more about missing BASE report.

Additional details and impacted files

@@                      Coverage Diff                      @@
##             release-nextgen-20251011     #67509   +/-   ##
=============================================================
  Coverage                            ?   71.8513%           
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  Files                               ?       1833           
  Lines                               ?     492923           
  Branches                            ?          0           
=============================================================
  Hits                                ?     354172           
  Misses                              ?     115415           
  Partials                            ?      23336           

Flag	Coverage Δ
unit	71.8513% <56.2500%> (?)

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

Components	Coverage Δ
dumpling	56.3493% <0.0000%> (?)
parser	∅ <0.0000%> (?)
br	46.5808% <0.0000%> (?)

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[YangKeao]

/unhold