release: v8.4.0-DMR

[yinsustart]

Disclaimer The dates published in this issue are for planning purposes only. It is intended solely to help you plan your projects. A date that exists in the future should not be considered a firm release date as the release and timing of releases are subject to change at any time and are at PingCAP's sole discretion.

Release process checklist Candidate SHA: TBD

Working Tags: TBD

Check the diff in the current version:

• [x] 0. Announce the release plan

• [x] 1. Create release-8.4 branch: Oct. 10, 2024

• [x] 2. Code freeze: Oct. 10, 2024

• [x] 3. Qualifying the release.

• [x] 4. Docs preparing for release.

• [ ] 5. The release qualified.

• [ ] 6. Docs ready for release.

release date: Nov. 2024

Do not proceed below until the release date.

• [ ] 7. Publish TiDB Release

fill in Candidate SHA above

fill in Make and Publish Build above

• [ ] 8. Update version numbers

• [ ] 9. Update docs (handled by Docs team)

• [ ] 10. Update the official website

[yinsustart]

We are sorry to announce that TiDB v8.4.0 release will be postponed from October to November.

Reason and next plan: Reason

• We've discovered a TiKV OOM issue related to CDC, Titan, and PiTR during regression testing.While the root cause is still being investigated, we have identified the direct cause as CDC tasks accumulating in the "apply" to "cdc" channel due to slow processing of old_value_cb, which is overloading the CDC thread.

Next plan

• Will use a bisecting approach to identify suspicious commits. Concurrently, the CDC team will take steps to alleviate the OOM issue.

• We are strictly following the release schedule, but the current issue has the potential to introduce OOM issues that carry quality risks. After a careful assessment, it needs more time to resolve it before release.