Momento/monitoring/alerts.yml

groups:
  - name: critical
    rules:
      - alert: MementoAppDown
        expr: up{job="memento-app"} == 0
        for: 2m
        labels:
          severity: critical
        annotations:
          summary: "🔴 Memento app is DOWN"
          description: "The Next.js application has been unreachable for 2+ minutes."

      - alert: PostgresDown
        expr: up{job="postgres"} == 0
        for: 1m
        labels:
          severity: critical
        annotations:
          summary: "🔴 PostgreSQL is DOWN"
          description: "Database has been unreachable for 1+ minute."

      - alert: RedisDown
        expr: up{job="redis"} == 0
        for: 1m
        labels:
          severity: critical
        annotations:
          summary: "🔴 Redis is DOWN"
          description: "Redis cache/quota store has been unreachable for 1+ minute."

  - name: resources
    rules:
      - alert: DiskSpaceLow
        expr: (node_filesystem_avail_bytes{mountpoint="/"} / node_filesystem_size_bytes{mountpoint="/"}) < 0.15
        for: 5m
        labels:
          severity: warning
        annotations:
          summary: "⚠️ Disk space below 15%"
          description: "Only {{ humanizePercentage (div (node_filesystem_avail_bytes{mountpoint='/'}) (node_filesystem_size_bytes{mountpoint='/'})) }} disk space remaining."

      - alert: DiskSpaceCritical
        expr: (node_filesystem_avail_bytes{mountpoint="/"} / node_filesystem_size_bytes{mountpoint="/"}) < 0.05
        for: 1m
        labels:
          severity: critical
        annotations:
          summary: "🔴 Disk space CRITICAL (< 5%)"

      - alert: HighMemoryUsage
        expr: (1 - node_memory_MemAvailable_bytes / node_memory_MemTotal_bytes) > 0.90
        for: 5m
        labels:
          severity: warning
        annotations:
          summary: "⚠️ Memory usage above 90%"

      - alert: HighCPUUsage
        expr: 100 - (avg by(instance) (rate(node_cpu_seconds_total{mode="idle"}[5m])) * 100) > 85
        for: 10m
        labels:
          severity: warning
        annotations:
          summary: "⚠️ CPU usage above 85% for 10 minutes"

  - name: database
    rules:
      - alert: PostgresConnectionsHigh
        expr: pg_stat_activity_count > 80
        for: 5m
        labels:
          severity: warning
        annotations:
          summary: "⚠️ PostgreSQL connections above 80"

      - alert: PostgresSlowQueries
        expr: pg_stat_statements_mean_exec_seconds > 5
        for: 5m
        labels:
          severity: warning
        annotations:
          summary: "⚠️ PostgreSQL slow queries detected (avg > 5s)"

      - alert: RedisMemoryHigh
        expr: redis_memory_used_bytes / redis_memory_max_bytes > 0.85
        for: 5m
        labels:
          severity: warning
        annotations:
          summary: "⚠️ Redis memory above 85% of limit"

  - name: application
    rules:
      - alert: HighErrorRate
        expr: rate(http_requests_total{status=~"5.."}[5m]) > 0.05
        for: 3m
        labels:
          severity: warning
        annotations:
          summary: "⚠️ HTTP 5xx error rate above 5%"

      - alert: AppHighHeapMemory
        expr: memento_process_heap_used_bytes / memento_process_heap_total_bytes > 0.90
        for: 5m
        labels:
          severity: warning
        annotations:
          summary: "⚠️ Next.js heap usage above 90%"

      - alert: ContainerRestarted
        expr: increase(container_restart_count[1h]) > 0
        for: 1m
        labels:
          severity: warning
        annotations:
          summary: "⚠️ Container restarted in the last hour"
          description: "Container {{ $labels.name }} restarted unexpectedly."

  # ── Business Alerts ──────────────────────────────────────────────────────────
  - name: business
    rules:
      - alert: HighChurnRate
        expr: memento_churn_this_month > 10
        for: 0m
        labels:
          severity: warning
        annotations:
          summary: "📉 Churn élevé ce mois : {{ $value }} désabonnements"
          description: "Plus de 10 désabonnements enregistrés ce mois. Investiguer les raisons."

      - alert: NoNewUsersLast7Days
        expr: memento_new_users_7d == 0
        for: 1h
        labels:
          severity: warning
        annotations:
          summary: "📊 Aucune nouvelle inscription depuis 7 jours"
          description: "Vérifier le funnel d'onboarding et les canaux d'acquisition."

      - alert: AgentRunsHighErrorRate
        expr: |
          memento_agent_runs_30d{status="error"} /
          (memento_agent_runs_30d{status="success"} + memento_agent_runs_30d{status="error"} + 1) > 0.2
        for: 5m
        labels:
          severity: warning
        annotations:
          summary: "🤖 Taux d'erreur agents IA > 20% ce mois"
          description: "{{ $value | humanizePercentage }} des runs d'agents échouent."

      - alert: BusinessMetricsCollectionFailed
        expr: memento_business_metrics_error == 1
        for: 5m
        labels:
          severity: warning
        annotations:
          summary: "⚠️ Collecte métriques business en erreur"
          description: "L'endpoint /api/metrics ne peut pas interroger la base pour les métriques business."