feat(monitoring): Sprint 5.2 Plan B — 資料庫詳細告警規則

新增 database_detail_alerts 規則群組:
  PostgreSQL:
    - PostgreSQLSlowQueries: 慢查詢 >60s
    - PostgreSQLDeadlocks: 死鎖發生
    - PostgreSQLTooManyConnections: 連接數 >50
  Redis:
    - RedisKeyEviction: Key 驅逐
    - RedisConnectionsHigh: 連接數 >100
    - RedisCommandLatencyHigh: 命令延遲 >10ms

前置: postgres-exporter:9187 + redis-exporter:9121 已在 188 部署 ✅
Prometheus scrape 已更新 ✅

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

ops/monitoring/alerts-unified.yml

@@ -204,6 +204,99 @@ groups:
           summary: "Redis 記憶體使用過高"
           description: "Redis 記憶體使用率超過 80%"
 
+  # =========================================================================
+  # Sprint 5.2 Plan B: 資料庫詳細指標告警 (database_detail_alerts)
+  # 前置: postgres-exporter:9187 + redis-exporter:9121 on 192.168.0.188
+  # 2026-04-08 Claude Sonnet 4.6 Asia/Taipei
+  # =========================================================================
+  - name: database_detail_alerts
+    rules:
+      # ---- PostgreSQL 詳細指標 ----
+      - alert: PostgreSQLSlowQueries
+        expr: pg_stat_activity_max_tx_duration{datname="awoooi_prod"} > 60
+        for: 5m
+        labels:
+          severity: warning
+          layer: systemd-188
+          component: postgres
+          host: "188"
+          team: ops
+          auto_repair: "false"
+        annotations:
+          summary: "PostgreSQL 有慢查詢 (>60s)"
+          description: "awoooi_prod 資料庫最長事務超過 60 秒"
+
+      - alert: PostgreSQLDeadlocks
+        expr: increase(pg_stat_database_deadlocks{datname="awoooi_prod"}[5m]) > 0
+        for: 1m
+        labels:
+          severity: warning
+          layer: systemd-188
+          component: postgres
+          host: "188"
+          team: ops
+          auto_repair: "false"
+        annotations:
+          summary: "PostgreSQL 死鎖發生"
+          description: "過去 5 分鐘 awoooi_prod 資料庫有死鎖"
+
+      - alert: PostgreSQLTooManyConnections
+        expr: pg_stat_activity_count{datname="awoooi_prod"} > 50
+        for: 5m
+        labels:
+          severity: warning
+          layer: systemd-188
+          component: postgres
+          host: "188"
+          team: ops
+          auto_repair: "false"
+        annotations:
+          summary: "PostgreSQL 連接數過高 ({{ $value }})"
+          description: "awoooi_prod 連接數超過 50"
+
+      # ---- Redis 詳細指標 ----
+      - alert: RedisKeyEviction
+        expr: increase(redis_evicted_keys_total[5m]) > 0
+        for: 1m
+        labels:
+          severity: warning
+          layer: systemd-188
+          component: redis
+          host: "188"
+          team: ops
+          auto_repair: "false"
+        annotations:
+          summary: "Redis 發生 Key 驅逐"
+          description: "過去 5 分鐘有 Key 被驅逐，可能記憶體不足"
+
+      - alert: RedisConnectionsHigh
+        expr: redis_connected_clients > 100
+        for: 5m
+        labels:
+          severity: warning
+          layer: systemd-188
+          component: redis
+          host: "188"
+          team: ops
+          auto_repair: "false"
+        annotations:
+          summary: "Redis 連接數過高 ({{ $value }})"
+          description: "Redis 連接數超過 100"
+
+      - alert: RedisCommandLatencyHigh
+        expr: redis_commands_duration_seconds_total / redis_commands_processed_total > 0.01
+        for: 5m
+        labels:
+          severity: warning
+          layer: systemd-188
+          component: redis
+          host: "188"
+          team: ops
+          auto_repair: "false"
+        annotations:
+          summary: "Redis 命令平均延遲過高 (>10ms)"
+          description: "Redis 命令平均延遲超過 10ms"
+
   # =========================================================================
   # 服務可用性告警 (service_alerts) — 含 layer 標籤決定修復路徑
   # =========================================================================