B システム設計/インフラ — campaign-event-worker Pub/Subバックログ駆動オートスケーリング（KEDA gcp-pubsubスケーラー × PodDisruptionBudget × topologySpreadConstraintsによるゾーン分散 × graceful shutdown(SIGTERM+preStop+ack完了待ち) × VPA推奨値によるrequests適正化 × minReplicas冗長性 × liveness/readiness責務分離）（MOps キャンペーンイベントワーカー Bad→Good）

📋 コピー# ── Deployment ──────────────────────────────────────────────
apiVersion: apps/v1
kind: Deployment
metadata:
  name: campaign-event-worker
spec:
  replicas: 2   # 修正②: KEDAが上書き管理するが初期値として冗長性を持たせる
  selector:
    matchLabels: { app: campaign-event-worker }
  template:
    metadata:
      labels: { app: campaign-event-worker }
    spec:
      # 修正⑤: ack完了を待つための猶予を確保
      terminationGracePeriodSeconds: 90
      # 修正④: ゾーンを跨いでPodを分散配置
      topologySpreadConstraints:
        - maxSkew: 1
          topologyKey: topology.kubernetes.io/zone
          whenUnsatisfiable: DoNotSchedule
          labelSelector:
            matchLabels: { app: campaign-event-worker }
      containers:
        - name: worker
          image: asia-northeast1-docker.pkg.dev/PROJECT_ID/mops/campaign-event-worker:latest
          resources:
            # 修正⑥: VPA推奨値(0.3vCPU/512MiB)を踏まえ適正化
            # Autopilotは0.25vCPU刻みで量子化されるため0.5vCPUに切り上げ
            requests: { cpu: "500m", memory: "512Mi" }
            limits:   { cpu: "1000m", memory: "1Gi" }
          # 修正⑦: livenessはプロセス生存確認のみ
          livenessProbe:
            httpGet: { path: /livez, port: 8080 }
            periodSeconds: 15
            failureThreshold: 3
          # 修正⑦: readinessはPub/Sub接続込みの依存先確認
          readinessProbe:
            httpGet: { path: /readyz, port: 8080 }
            periodSeconds: 10
            failureThreshold: 2
          lifecycle:
            # 修正⑤: 新規pull停止 → ack完了待ち → 正常終了
            preStop:
              exec:
                command: ["/bin/sh", "-c", "kill -SIGUSR1 1 && sleep 60"]

---
# ── PodDisruptionBudget（修正③）───────────────────────────────
apiVersion: policy/v1
kind: PodDisruptionBudget
metadata:
  name: campaign-event-worker-pdb
spec:
  minAvailable: 1
  selector:
    matchLabels: { app: campaign-event-worker }

---
# ── KEDA ScaledObject（修正①②）────────────────────────────────
apiVersion: keda.sh/v1alpha1
kind: ScaledObject
metadata:
  name: campaign-event-worker
spec:
  scaleTargetRef: { name: campaign-event-worker }
  minReplicaCount: 2
  maxReplicaCount: 30
  cooldownPeriod: 120
  triggers:
    - type: gcp-pubsub
      authenticationRef: { name: keda-pubsub-auth }
      metadata:
        subscriptionName: campaign-event-sub
        mode: SubscriptionSize
        value: "100"

---
# ── TriggerAuthentication（Workload Identity経由）───────────────
apiVersion: keda.sh/v1alpha1
kind: TriggerAuthentication
metadata:
  name: keda-pubsub-auth
spec:
  podIdentity:
    provider: gcp