"Patroni"
- PostgreSQL Patroni HA：從 leader 失聯到 client 重連的 5 段 failover lifecycle Patroni 把 PostgreSQL HA 拆成 detection / election / promotion / reconfiguration / recovery 五段 lifecycle、每段都有獨立配置跟 failure mode；DCS quorum + watchdog 防 split-brain、async/sync replication 取捨、5 個 production 踩雷、跟 PgBouncer / HAProxy / cert-manager 整合