[AWS] Route 53: DNS, routing policies, health checks

Route 53, Route53, DNS, weighted routing, latency routing, failover routing, geolocation

정의

Route 53 = AWS 의 글로벌 DNS + health check + 라우팅 정책. 단순 DNS 뿐 아니라 글로벌 트래픽 분산.

Hosted Zone

Hosted Zone: example.com
└── Record:
    A      api.example.com   →  192.0.2.1
    CNAME  www.example.com   →  example.com
    MX     example.com       →  mail.example.com
    TXT    _verification     →  "google-site-verification=..."

Alias Record (AWS 전용)

A alias api.example.com → AWS Load Balancer (xx.amazonaws.com)

CNAME 보다:

• root domain 가능 (CNAME 은 root 불가)
• 무료 query
• IP 자동 갱신

라우팅 정책 7가지

flowchart TB
    Q[Routing Policy]
    Q --> Simple[Simple]
    Q --> Weighted[Weighted<br/>10% canary]
    Q --> Latency[Latency<br/>가장 빠른 region]
    Q --> Failover[Failover<br/>primary + secondary]
    Q --> Geo[Geolocation<br/>국가별]
    Q --> GeoProx[Geoproximity<br/>바이어스 적용]
    Q --> MV[Multi-Value Answer<br/>여러 IP 반환]

Weighted (Canary)

api.example.com (200)
  → 10% → 신 ALB
  → 90% → 옛 ALB

Latency-Based

flowchart LR
    Client[Asia 사용자] -->|DNS query| R53[Route 53]
    R53 -->|measure latency| Asian[Asia ALB]
    R53 -->|measure| US[US ALB]
    R53 -->|measure| EU[EU ALB]
    R53 -->|가장 빠른 = Asia| Client
    Client --> Asian

Failover

primary: api-prod.example.com (health check)
secondary: api-dr.example.com (health check)

primary unhealthy → secondary 자동 응답.

Health Check

HealthCheck:
  Type: HTTPS
  ResourcePath: /health
  FullyQualifiedDomainName: api.example.com
  RequestInterval: 30
  FailureThreshold: 3
  Regions: [us-east-1, us-west-2, ap-northeast-1]  # 다중 region 동시 체크

3개 region 의 과반 이상 unhealthy → unhealthy 판정.

DNSSEC

aws route53 enable-hosted-zone-dnssec --hosted-zone-id Z0123

DNS 응답에 디지털 서명 → DNS 위조 (cache poisoning) 방어.

Private Hosted Zone

domain: internal.local
visibility: VPC associated

VPC 안에서만 resolve. 내부 service 명명에 활용.

흔한 함정

관련 위키

• network-dns
• aws-alb-nlb
• aws-cloudfront-cdn
• aws-vpc