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

# Runbook: DB_UNAVAILABLE (`runbook://db/unavailable`)

## Symptoms

- HTTP 503 with `error.code=DB_UNAVAILABLE`
- SQLState 08* connection errors in logs

## Diagnosis

- Check DB server health and connection pool exhaustion
- Review network connectivity from app pods to DB

## Action

- Check DB primary health; failover to replica if available
- Drain connection pool and reconnect

## Escalation

- P1: immediate if DB primary is down

---

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