DOC-2197: Add Redpanda SQL metrics reference section

[kbatuigas]

Appends a cloud-only section (ifdef::env-cloud[]) documenting 67 Oxla Prometheus metrics across admission, catalog, cluster, executor, kafka, memory, network, query, scheduler, and storage subsystems.

Description

Resolves https://redpandadata.atlassian.net/browse/
Review deadline:

Page previews

Checks

• New feature
• Content gap
• Support Follow-up
• Small fix (typos, links, copyedits, etc)

[coderabbitai]

📝 Walkthrough

Walkthrough

This PR adds a new "Redpanda SQL metrics" documentation section to the public metrics reference guide. The section is conditioned on the cloud environment and introduces oxla_-prefixed metric entries covering SQL engine monitoring areas including admissions, object storage requests, catalog transactions, cluster and node state, data-task execution, executor/scheduler/thread-pool operations, query execution statistics, PostgreSQL wire-protocol connections, and S3 lifecycle events. The documentation is inserted before the existing "Related topics" section.

Estimated code review effort

🎯 1 (Trivial) | ⏱️ ~3 minutes

Possibly related PRs

• redpanda-data/docs#1509: Both PRs expand modules/reference/pages/public-metrics-reference.adoc with new metric documentation entries under the same env-cloud cloud metrics sections.

Suggested reviewers

• micheleRP
• nicolaferraro
• r-vasquez

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 inconclusive)

Check name	Status	Explanation	Resolution
Description check	❓ Inconclusive	The description is largely incomplete. While it mentions the change details, it has unfilled template placeholders and unchecked checklist items.	Fill in the Jira ticket number in the Resolves link, add a review deadline if needed, provide actual page preview links, and check the appropriate checkbox(s) for the type of change.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly and specifically summarizes the main change: adding a Redpanda SQL metrics reference section to documentation.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
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.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch DOC-2197-sql-monitoring

---

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

[netlify]

✅ Deploy Preview for redpanda-docs-preview ready!

Name	Link
🔨 Latest commit	87aa10d
🔍 Latest deploy log	https://app.netlify.com/projects/redpanda-docs-preview/deploys/6a1905bc058af60009900d92
😎 Deploy Preview	https://deploy-preview-1721--redpanda-docs-preview.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify project configuration.

[coderabbitai]

🧹 Nitpick comments (1)

modules/reference/pages/public-metrics-reference.adoc (1)

3541-4142: ⚡ Quick win

Consider adding "Available in Serverless" indicators for consistency.

The SQL metrics section is cloud-only (wrapped in ifdef::env-cloud[]), but unlike other cloud metrics in this file (e.g., Serverless metrics at lines 1434-1502), individual metrics don't include *Available in Serverless*: Yes/No tags. Since the section intro (line 3539) specifies "BYOC clusters," these metrics appear to be unavailable in Serverless.

For consistency with the established pattern throughout this file, consider adding the following after each metric's *Type*: line (and before any *Labels*: or --- separator):

*Available in Serverless*: No

This would match the documentation style used for other cloud metrics and improve clarity for readers.

🤖 Prompt for AI Agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@modules/reference/pages/public-metrics-reference.adoc` around lines 3541 -
4142, This SQL metrics block (metrics named like oxla_admission_active_queries
through oxla_writers_opened_total) is cloud-only but lacks the "Available in
Serverless" tag; add a line "*Available in Serverless*: No" immediately after
each metric's "*Type*:" line (and before any "*Labels*:" or the "---" separator)
for every metric in this section so it matches the established pattern used
elsewhere.

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Nitpick comments:
In `@modules/reference/pages/public-metrics-reference.adoc`:
- Around line 3541-4142: This SQL metrics block (metrics named like
oxla_admission_active_queries through oxla_writers_opened_total) is cloud-only
but lacks the "Available in Serverless" tag; add a line "*Available in
Serverless*: No" immediately after each metric's "*Type*:" line (and before any
"*Labels*:" or the "---" separator) for every metric in this section so it
matches the established pattern used elsewhere.

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: 62a4e0e2-a179-4713-8175-457794e88858

📥 Commits

Reviewing files that changed from the base of the PR and between 5d49714 and 87aa10d.

📒 Files selected for processing (1)

• modules/reference/pages/public-metrics-reference.adoc