---
title: Runbook — CACHE_UNAVAILABLE (캐시 연결 불가)
category: TRANSIENT_DEPENDENCY
error_codes: [CACHE_UNAVAILABLE]
severity: P1
owner: oncall
last_updated: 2026-06-15
status: stub
---

# Runbook: CACHE_UNAVAILABLE (`runbook://cache/unavailable`)

## Symptoms

- HTTP 503 with `error.code=CACHE_UNAVAILABLE`
- Redis connection errors in logs

## Diagnosis

- Check Redis cluster health
- Verify network connectivity from app to Redis

## Action

- Check Redis sentinel/cluster status
- Enable cache degradation path if configured for optional caches

## Escalation

- P1 if required cache is down and no degradation path exists

---

> **Stub**: Phase D2 — author body after domain adoption. (feature-operational-runbook-contract D9)