---
title: Runbook — DB_SERIALIZATION_FAILURE (직렬화 실패)
category: CONFLICT
error_codes: [DB_SERIALIZATION_FAILURE]
severity: P3
owner: oncall
last_updated: 2026-06-15
status: stub
---

# Runbook: DB_SERIALIZATION_FAILURE (`runbook://db/serialization-failure`)

## Symptoms

- HTTP 409 with `error.code=DB_SERIALIZATION_FAILURE`
- SQLState 40001; high concurrent transaction contention

## Diagnosis

- Check DB transaction isolation level
- Identify hot rows / hot tables under high concurrency

## Action

- Client should retry with exponential backoff (retryable=true)
- Optimize transaction scope if spike is sustained

## Escalation

- Escalate to DBA if sustained serialization failure rate > 5%

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