Update the Compatibility changes of release-8.5.4 #22233

Frank945946 · 2025-12-24T10:12:25Z

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gemini-code-assist · 2025-12-24T10:12:47Z

Summary of Changes

Hello @Frank945946, 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 updates the release-8.5.4.md documentation to clearly outline compatibility changes for the TiDB 8.5.4 release. The changes provide a structured overview of system variable and configuration parameter adjustments, including new additions, default value modifications, and deprecations, ensuring users are well-informed about potential impacts on their deployments, especially those with specialized configurations.

Highlights

Upgrade Compatibility Guidance: The documentation now includes explicit guidance for upgrading from v8.5.3 to v8.5.4, emphasizing the need for careful review for clusters with customized performance tuning, TiFlash, or TiKV compaction settings due to default value and behavior adjustments.
System Variable Adjustments and Additions: Key system variables like tidb_mpp_store_fail_ttl (default changed to 0s for faster TiFlash query dispatch) and tidb_replica_read (now strictly for read-only SQL) have been updated. New variables such as tidb_opt_enable_no_decorrelate_in_select, tidb_opt_enable_semi_join_rewrite, and tidb_stats_update_during_ddl have been introduced to enhance query optimization and DDL processes.
Configuration Parameter Overhauls: Several TiKV configuration parameters, including max-manifest-file-size, grpc-raft-conn-num, and grpc-concurrency, have seen their default values or calculation methods updated. A significant change involves the deprecation of older region-compact-* parameters in favor of a new gc.auto-compaction configuration group for improved automatic compaction control.
TiFlash Shutdown Control: A new TiFlash configuration item, flash.graceful_wait_shutdown_timeout, has been added to manage the maximum wait time during graceful shutdowns, ensuring ongoing MPP tasks can complete while preventing new ones.

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Code Review

This pull request refactors the 'Compatibility changes' section of the release notes for v8.5.4. The changes introduce a 'Highlights' section and convert the lists of system variable and configuration parameter changes into tables, which significantly improves readability. My feedback focuses on adjusting the heading structure to comply with the documentation style guide for proper hierarchy and casing.

releases/release-8.5.4.md

Frank945946

LGTM

releases/release-8.5.4.md

ti-chi-bot · 2026-01-13T08:39:13Z

[LGTM Timeline notifier]

Timeline:

2026-01-13 08:39:12.731055822 +0000 UTC m=+346796.792920723: ☑️ agreed by hfxsd.

hfxsd · 2026-01-13T08:47:43Z

/approve

ti-chi-bot · 2026-01-13T08:48:06Z

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: hfxsd

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ti-chi-bot · 2026-01-13T08:52:22Z

In response to a cherrypick label: new pull request created to branch release-8.5: #22316.

* origin/release-8.5: (48 commits) Terraform: remove `cluster_id` in `cluster_id, vpc_peering_id` (#22318) Update the Compatibility changes of release-8.5.4 (#22233) (#22316) cloud: optimize the description of TiDB-X features (#22294) Add FORMAT keyword to import statement options (#22301) (#22304) cloud: delete disaster recovery (#22299) v8.5.4 tikv: update default settings of `server.grpc-concurrency` and `server.grpc-raft-conn-num`. (#22273) (#22298) Update create-tidb-instance-premium.md (#22288) sync-diff-inspector: add PROCESS permission when upstream and downstream are TiDB (#22289) (#22292) sql-faq: fix outdated description about JDBC (#22283) (#22287) master, v8.5: update download URL from pingcap.org to pingcap.com (#22240) (#22280) tikv: fix the default value of `end-point-memory-quota` (#22271) (#22272) v8.5.4: tikv: update auto compaction config (#22251) (#22265) pdf: update year to 2026 in copyright.tex (#22253) (#22260) v8.5.4 tikv: update rocksdb.max-manifest-file-size default value (#21689) (#22250) tidb-cloud: update the RU definition (#22197) cloud: update backup policies and execution rules (#22227) cloud: add release notes for 20251230 (#22247) cloud: add private link connection docs for overview and Confluent (#22246) tiproxy: add tiproxy usage in the tidb cloud doc (#21483) cloud: update the retention note for the latest automatic backup (#22248) ...

Update the Compatibility changes of release-8.5.4

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ti-chi-bot bot added contribution This PR is from a community contributor. missing-translation-status This PR does not have translation status info. size/M Denotes a PR that changes 30-99 lines, ignoring generated files. labels Dec 24, 2025

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qiancai added 3 commits January 12, 2026 13:57

format udpates

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Update release-8.5.4.md

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Merge branch 'upstream-master' into pr/22233

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hfxsd added translation/from-docs-cn This PR is translated from a PR in pingcap/docs-cn. needs-cherry-pick-release-8.5 Should cherry pick this PR to release-8.5 branch. and removed missing-translation-status This PR does not have translation status info. labels Jan 12, 2026

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Update the Compatibility changes of release-8.5.4 (pingcap#22233)

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Update the Compatibility changes of release-8.5.4 (#22233) #22316

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Update the Compatibility changes of release-8.5.4 (#22233) (#22316)

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Update the Compatibility changes of release-8.5.4 #22233

Update the Compatibility changes of release-8.5.4 #22233

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Frank945946 commented Dec 24, 2025 • edited by hfxsd Loading Uh oh! There was an error while loading. Please reload this page.

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[LGTM Timeline notifier]

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Frank945946 commented Dec 24, 2025 •

edited by hfxsd

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