{
  "schema": "pg36-ch20-ha-requirements-v1",
  "release": "1.0-sandbox",
  "status": "planned-switchover-contract-not-production-slo",
  "target": {
    "id": "pg36-l2-vagrant/pg-test",
    "pigsty_release": "v4.4.0",
    "postgresql_major": 18,
    "patroni_version": "4.1.3",
    "cluster": "pg-test",
    "system_identifier_source": "live chapter-19 evidence",
    "production_data_permitted": false,
    "production_traffic_permitted": false
  },
  "members": {
    "pg-test-1": {
      "address": "10.10.10.11",
      "initial_role": "primary",
      "forward_role": "replica",
      "restored_role": "primary"
    },
    "pg-test-2": {
      "address": "10.10.10.12",
      "initial_role": "replica",
      "forward_role": "primary",
      "restored_role": "replica"
    },
    "pg-test-3": {
      "address": "10.10.10.13",
      "initial_role": "replica",
      "forward_role": "replica",
      "restored_role": "replica",
      "offline_query": true
    }
  },
  "planned_actions": {
    "forward": {
      "leader": "pg-test-1",
      "candidate": "pg-test-2",
      "kind": "planned-switchover",
      "executor": "patronictl"
    },
    "restore_teaching_baseline": {
      "leader": "pg-test-2",
      "candidate": "pg-test-1",
      "kind": "planned-switchover",
      "executor": "patronictl"
    }
  },
  "client_probe": {
    "database": "test",
    "user": "test",
    "service_host": "10.10.10.11",
    "service_port": 5433,
    "target_session_attrs": "read-write",
    "sslmode": "prefer",
    "duration_seconds": 24,
    "interval_seconds": 0.2,
    "warmup_seconds": 3,
    "minimum_acknowledged_attempts": 30,
    "maximum_observed_write_gap_ms": 15000,
    "maximum_acknowledged_rows_missing": 0,
    "maximum_duplicate_tokens": 0,
    "maximum_unreconciled_unknown_outcomes": 0,
    "measurement_resolution_note": "write-gap includes one probe interval and is not a production RTO SLI"
  },
  "topology_acceptance": {
    "maximum_pre_switch_replay_lag_bytes": 1048576,
    "stable_timeout_seconds": 45,
    "same_system_identifier_on_all_members": true,
    "timeline_must_advance_on_forward": true,
    "timeline_must_advance_on_restore": true,
    "all_nonleaders_must_be_streaming": true,
    "final_leader_must_return_to": "pg-test-1"
  },
  "expected_dynamic_policy": {
    "ttl_seconds": 30,
    "loop_wait_seconds": 5,
    "retry_timeout_seconds": 10,
    "maximum_lag_on_failover_bytes": 1048576,
    "synchronous_mode": false,
    "synchronous_mode_strict": false,
    "failsafe_mode": true,
    "use_pg_rewind": true,
    "use_slots": true,
    "watchdog_mode": "off",
    "dcs_kind": "etcd3",
    "dcs_member_count": 1
  },
  "required_exception_ids": [
    "EX19-SHARED-HYPERVISOR",
    "EX19-SINGLE-ETCD",
    "EX19-SINGLE-BACKUP-TARGET",
    "EX19-VIRTUAL-STORAGE",
    "EX19-INVENTORY-SECRETS",
    "EX19-LAB-RESOURCE-FLOOR",
    "EX20-ASYNC-BASELINE",
    "EX20-WATCHDOG-OFF",
    "EX20-CLIENT-PROXY-NO-TLS",
    "EX20-PLANNED-ONLY"
  ],
  "exceptions": [
    {
      "id": "EX20-ASYNC-BASELINE",
      "reason": "pg-test uses asynchronous streaming replication and synchronous_mode=false",
      "claim_blocked": "zero RPO and synchronous-commit durability"
    },
    {
      "id": "EX20-WATCHDOG-OFF",
      "reason": "Patroni watchdog mode is off in the Vagrant guests",
      "claim_blocked": "hardware-watchdog fencing and automatic isolation of a stalled old primary"
    },
    {
      "id": "EX20-CLIENT-PROXY-NO-TLS",
      "reason": "the sandbox port-5433 PgBouncer service does not accept TLS from the external probe",
      "claim_blocked": "production transport-security acceptance for the client service path"
    },
    {
      "id": "EX20-PLANNED-ONLY",
      "reason": "this formal drill performs healthy planned switchovers and no unplanned process, host, storage, network, or DCS fault",
      "claim_blocked": "automatic failover, fencing, split-brain exclusion, and failure-time RPO/RTO"
    }
  ],
  "decision_boundary": {
    "sandbox_planned_switchover": "may-pass-with-exceptions",
    "production_ch20_gate": "pending",
    "unplanned_failure_drill": "deferred-to-a-separately-authorized-chapter-33-exercise",
    "backup_recovery": "chapter-21",
    "client_routing_contract": "chapter-22",
    "security": "chapter-23"
  }
}