[Load Balancing] Document regional health

[ncrouch-cflare]

Add a concept page for regional health, covering the reasons per-region health decisions exist, the local/regional/global health sources, how health_sources differs from check_regions, two worked examples, the recommended pool configuration, and when not to use the feature.

Every behavioral claim is validated against the Load Balancing source tree (ctm-topology, ctm-director, ctm-health).

The launch changelog entry is deliberately not included in this commit. It will land in a follow-up once the public launch date is confirmed.

Validated locally:
pnpm run check PASS (0 errors, 0 warnings)
pnpm run build PASS (8732 pages)
pnpm run lint PASS
pnpm run format:core:check PASS

Summary

Screenshots (optional)

Documentation checklist

• Is there a changelog entry (guidelines)? If you don't add one for something awesome and new (however small) — how will our customers find out? Changelogs are automatically posted to RSS feeds, the Discord, and X.
• The change adheres to the documentation style guide.
• If a larger change - such as adding a new page- an issue has been opened in relation to any incorrect or out of date information that this PR fixes.
• Files which have changed name or location have been allocated redirects.

[cloudflare-docs-bot]

Review

⚠️ 1 warning found in commit 1d765d7.

👉 Fix in your agent 👈

Fix the following review findings in PR #32373 (https://github.com/cloudflare/cloudflare-docs/pull/32373).

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---

## Code Review

### Warnings (1)

#### CR-7752a6f895c2 · Inconsistent default health_sources behavior
- **File:** `src/content/docs/load-balancing/understand-basics/regional-health.mdx` line 61
- **Issue:** The doc first states that default behavior is a single global decision (line 19) and labels `global` as the default Load Balancing behavior (line 55). It then says an unset `health_sources` is equivalent to `["local", "global"]` (line 61). However, `local` applies only when `check_regions` is unset (line 53) and represents a per-data-center decision, not the global decision described earlier. The existing health-details page also notes that the All Data Centers case uses a majority-of-data-centers decision, which is still an aggregate, not a per-data-center `local` decision.
- **Fix:** Reconcile the default description. If unset truly preserves the existing single global/majority decision, state that explicitly and either remove `local` from the supported-sources table or clearly mark it as an internal-only fallback rather than a user-configurable source.

Code Review

This code review is in beta and may not always be helpful — use your judgment.

Warnings (1)

File

Issue

load-balancing/understand-basics/regional-health.mdx line 61

Inconsistent default health_sources behavior — The doc first states that default behavior is a single global decision (line 19) and labels global as the default Load Balancing behavior (line 55). It then says an unset health_sources is equivalent to ["local", "global"] (line 61). However, local applies only when check_regions is unset (line 53) and represents a per-data-center decision, not the global decision described earlier. The existing health-details page also notes that the All Data Centers case uses a majority-of-data-centers decision, which is still an aggregate, not a per-data-center local decision. Fix: Reconcile the default description. If unset truly preserves the existing single global/majority decision, state that explicitly and either remove local from the supported-sources table or clearly mark it as an internal-only fallback rather than a user-configurable source.

Conventions

_{No convention issues found.}

Style Guide Review

_{No style-guide issues found.}

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[github-actions]

This pull request requires reviews from CODEOWNERS as it changes files that match the following patterns:

Pattern	Owners
/src/content/docs/load-balancing/	@cloudflare/cf1-reviewers, @elithrar, @cloudflare/product-owners, @ncrouch-cflare

[github-actions]

Preview URL: https://1d765d7f.preview.developers.cloudflare.com
Preview Branch URL: https://docs-lb-regional-health.preview.developers.cloudflare.com

Files with changes (up to 15)

Original Link	Updated Link
https://developers.cloudflare.com/load-balancing/understand-basics/regional-health/	https://docs-lb-regional-health.preview.developers.cloudflare.com/load-balancing/understand-basics/regional-health/