docs(ha): update high availability documentation

[TheMeier]

clarify that --cluster.advertise-address requires
an IP address and port, hostnames are not supported.

Pull Request Checklist

Please check all the applicable boxes.

• Please list all open issue(s) discussed with maintainers related to this change
  • Related to hostname not supported in --cluster.advertise-address #1271
• I have added/updated the required documentation
• I have signed-off my commits
• I will follow best practices for contributing to this project

NONE

Summary by CodeRabbit

• Documentation
  • Updated example startup command to use a fixed advertise IP address.
  • Clarified that the cluster advertise address must be an IP in <ip>:<port> format (hostnames are not supported).
  • Noted that omitting the flag allows auto-detection, but using a hostname will log a warning and can leave the address unset, causing cluster communication failures.
  • Added explicit cloud/NAT example for configuring a routable IP.

[coderabbitai]

📝 Walkthrough

Walkthrough

Docs updated to require --cluster.advertise-address be an IP in <ip>:<port> format (not a hostname); example startup command changed to use a fixed IP and guidance on auto-detection and cloud/NAT scenarios was clarified.

Changes

Cohort / File(s)	Summary
Documentation Update docs/high_availability.md	Changed example to use --cluster.advertise-address=192.0.2.1:9094; clarified flag requires an IP (<ip>:<port>), tightened guidance about auto-detection when omitted, and added note that hostnames are unsupported and can cause cluster communication failures (cloud/NAT example added).

Estimated code review effort

🎯 1 (Trivial) | ⏱️ ~3 minutes

Possibly related issues

• clustering: --cluster.advertise-address implicitly expects an IP address and does not let one use a hostname #5111 — Docs change documents the same advertise-address IP requirement and guidance tightened here.
• #1271: hostname not supported in --cluster.advertise-address — This PR documents and clarifies the behavior reported in the issue (hostnames are unsupported; use an IP).

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 inconclusive)

Check name	Status	Explanation	Resolution
Title check	❓ Inconclusive	The title 'docs(ha): update high availability documentation' is vague and generic, using non-descriptive terms that don't convey the specific change about clarifying IP address requirements.	Consider a more specific title like 'docs(ha): clarify that cluster.advertise-address requires IP addresses not hostnames' to better describe the actual change.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Linked Issues check	✅ Passed	The PR documentation updates directly address issue #1271's primary objective by clarifying that --cluster.advertise-address requires an IP address in : format, not hostnames.
Out of Scope Changes check	✅ Passed	All changes are documentation-only updates to high_availability.md focused on clarifying the IP address requirement, fully aligned with issue #1271 objectives.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Description check	✅ Passed	PR description covers the main objective (clarifying IP requirement for --cluster.advertise-address) and includes most required checklist items (documentation updated, signed-off commits, community guidelines acknowledged), but is missing the release-notes details despite marking completion.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@docs/high_availability.md`:
- Around line 396-397: Update the docs sentence to reflect that hostnames do not
cause a hard startup failure but can lead to misconfiguration: change the claim
that hostnames "will cause a startup error" to language like "will cause the
advertise address to be misconfigured, resulting in cluster communication
failures" and mention that hostname parsing only logs a warning in
calculateAdvertiseAddress() and Peer constructor (functions
calculateAdvertiseAddress and Peer) so startup continues with a potentially
incorrect advertise address.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

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ℹ️ Review info

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📥 Commits

Reviewing files that changed from the base of the PR and between 1d6097c and 2c36654.

📒 Files selected for processing (1)

• docs/high_availability.md

[Spaceman1701]

Lgtm. Read the code and I agree with the conclusion - it'll log a warning and do nothing.

We should probably change that, but it might break some people's deployments.

[SoloJacobs]

I would also like to see this fixed.