add v7.5.8 release notes

[doc-claw-bot]

What is changed, added or deleted? (Required)

• Add releases/release-7.5.8.md for the TiDB 7.5.8 patch release notes.
• Add the TiDB 7.5.8 entry to TOC-tidb-releases.md, releases/_index.md, and releases/release-timeline.md.
• Fill in the TiDB 7.5.8 release date.
• This release-notes update is prepared on release-8.5 because the release-notes directory is maintained there and will be cherry-picked to master.

Which TiDB version(s) do your changes apply to? (Required)

• master (the latest development version)
• v8.5 (TiDB 8.5 versions)
• v8.4 (TiDB 8.4 versions)
• v8.3 (TiDB 8.3 versions)
• v8.2 (TiDB 8.2 versions)
• v8.1 (TiDB 8.1 versions)
• v7.5 (TiDB 7.5 versions)
• v7.1 (TiDB 7.1 versions)
• v6.5 (TiDB 6.5 versions)

What is the related PR or file link(s)?

• This PR is translated from:
• Other reference link(s): add v7.5.8 release notes docs-cn#21930 ; generated from doc_4afdcdb19e49_release-7.5.8-updated-by-ai.md

AI agent involvement

• The changes in this PR were primarily made by an AI agent on behalf of the PR author.

Do your changes match any of the following descriptions?

• Delete files
• Change aliases
• Need modification after applied to another branch
• Might cause conflicts after applied to another branch

[coderabbitai]

Note

Reviews paused

It looks like this branch is under active development. To avoid overwhelming you with review comments due to an influx of new commits, CodeRabbit has automatically paused this review. You can configure this behavior by changing the reviews.auto_review.auto_pause_after_reviewed_commits setting.

Use the following commands to manage reviews:

• @coderabbitai resume to resume automatic reviews.
• @coderabbitai review to trigger a single review.

Use the checkboxes below for quick actions:

• ▶️ Resume reviews
• 🔍 Trigger review

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: ASSERTIVE

Plan: Team

Run ID: c9c77402-5b01-4e63-a835-ba0b11a17daa

📥 Commits

Reviewing files that changed from the base of the PR and between edadae6 and fd560fc.

📒 Files selected for processing (1)

• releases/release-7.5.8.md

Included review availability: Your plan provides up to 4 included reviews per hour; 1 remains after this review.

---

📝 Walkthrough

Walkthrough

The release page adds TiDB 7.5.8 metadata, one PD improvement, and bug fixes across TiDB, TiKV, PD, TiFlash, and TiCDC.

Changes

TiDB 7.5.8 release notes

Layer / File(s)	Summary
Release metadata and PD improvement releases/release-7.5.8.md	Adds release information, quick-access links, and the store label for the pd_cluster_status metric.
Component bug fixes releases/release-7.5.8.md	Documents fixes for executor shutdowns, planner CPU usage, statistics loading, safepoints, CDC connections, ingestion, PD stability, TiFlash nullability results, and TiCDC Kafka resource leaks.

Estimated code review effort: 2 (Simple) | ~10 minutes

Suggested reviewers: qiancai

Merge Risk: ⚪ Minimal · up to fd560

This release-notes update documents TiDB 7.5.8 improvements and fixes without changing runtime behavior. No merge-readiness risk remains.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check. Docstring coverage is scoped to functions touched by this diff. Analyzed 0 functions across 0…
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Title check	✅ Passed	The title clearly identifies the main change: adding TiDB v7.5.8 release notes.
Description check	✅ Passed	The description covers the required change, affected TiDB version, reference link, AI involvement, and change categories. It is consistent with the stated release-notes objective.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}

[coderabbitai]

Actionable comments posted: 1

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: ASSERTIVE

Plan: Team

Run ID: 0262028b-df7f-4cbc-986b-9efc3ef1b7b0

📥 Commits

Reviewing files that changed from the base of the PR and between 94afa8e and 1f82b2f.

📒 Files selected for processing (1)

• releases/release-7.5.8.md

Included review availability: Your plan provides up to 4 included reviews per hour; 3 remain after this review.

[lidezhu]

LGTM for CDC

[ti-chi-bot]

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

Details

In response to this:

LGTM for CDC

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.

[windtalker]

lgtm

[ti-chi-bot]

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

Details

In response to this:

lgtm

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.

[qw4990]

LGTM for the planner part

[ti-chi-bot]

@qw4990: adding LGTM is restricted to approvers and reviewers in OWNERS files.

Details

In response to this:

LGTM for the planner part

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.

[ti-chi-bot]

@JaySon-Huang: adding LGTM is restricted to approvers and reviewers in OWNERS files.

Details

In response to this:

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.

[YuhaoZhang00]

LGTM for PD

[ti-chi-bot]

@YuhaoZhang00: adding LGTM is restricted to approvers and reviewers in OWNERS files.

Details

In response to this:

LGTM for PD

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.

[ti-chi-bot]

@JaySon-Huang: adding LGTM is restricted to approvers and reviewers in OWNERS files.

Details

In response to this:

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.

[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2026-09-17 06:40:35.958690794 +0000 UTC m=+273681.896348398: ☑️ agreed by qiancai.

[qiancai]

/approve

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: qiancai

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 [qiancai]

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

[ti-chi-bot]

In response to a cherrypick label: new pull request created to branch master: #23902.