*: add slow log control variables (tidb_slow_log_rules, tidb_slow_log_max_per_sec) and hint write_slow_log

[lilin90]

What is changed, added or deleted? (Required)

pingcap/tidb#64010

Add slow log control variables (tidb_slow_log_rules, tidb_slow_log_max_per_sec) and hint write_slow_log

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

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By default, CHOOSE MASTER ONLY so your changes will be applied to the next TiDB major or minor releases. If your PR involves a product feature behavior change or a compatibility change, CHOOSE THE AFFECTED RELEASE BRANCH(ES) AND MASTER.

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• master (the latest development version)
• v9.0 (TiDB 9.0 versions)
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• v8.1 (TiDB 8.1 versions)
• v7.5 (TiDB 7.5 versions)
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• v6.5 (TiDB 6.5 versions)
• v6.1 (TiDB 6.1 versions)
• v5.4 (TiDB 5.4 versions)

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

• This PR is translated from: *: add slow log control variables (tidb_slow_log_rules, tidb_slow_log_max_per_sec) and hint write_slow_log docs-cn#21009
• Other reference link(s): Slow Log Enhancement: Multi-Dimensional Triggering and Dynamic Scope Control tidb#62959

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

[ti-chi-bot]

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[gemini-code-assist]

Summary of Changes

Hello @lilin90, 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 aims to enhance TiDB's slow log management capabilities. It introduces new system variables for fine-grained configuration of slow log rules and rate limiting, alongside a SQL hint to explicitly manage slow log recording for individual queries. This provides database administrators with improved tools for performance monitoring and debugging.

Highlights

• New Slow Log Control Variables: Introduces tidb_slow_log_rules and tidb_slow_log_max_per_sec to offer more precise control over slow log behavior and generation within TiDB.
• write_slow_log Hint: Adds a new hint, write_slow_log, enabling explicit control over whether a specific query's execution is recorded in the slow log.

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[gemini-code-assist]

Code Review

This pull request is intended to add documentation for tidb_slow_log_rules, tidb_slow_log_max_per_sec, and the write_slow_log hint. However, the only change submitted is the creation of a temporary file, temp.md, which does not contain the relevant documentation. The actual documentation files appear to be missing. Please update the pull request to include the correct files and content as described.

I am having trouble creating individual review comments. Click here to see my feedback.

temp.md (1)

This file appears to be a temporary placeholder and does not contain the documentation for the new slow log features as described in the pull request. This makes the documentation incomplete. Please remove this file and add the correct documentation content.

References

1. Per the style guide, documentation should be complete. This file is a placeholder and does not constitute complete documentation for the features mentioned in the pull request description. ^(link)