Why should you care?

PostgresVerse payment stack must survive AZ loss, operator error, and peak 10x traffic without manual heroics.

See it live — copy this example

Run in pgAdmin or psql.

-- Runbook excerpt as SQL checks
SELECT slot_name, active, pg_size_pretty(pg_wal_lsn_diff(pg_current_wal_lsn(), restart_lsn)) AS retained_wal
FROM pg_replication_slots;

SELECT archived_count, last_failed_time FROM pg_stat_archiver;

What happened?

• Replication slots show WAL retention — lagging subscriber can fill disk.
• pg_stat_archiver confirms WAL archive health for PITR leg of HA architecture.

Practice next

1. Document RPO/RTO per tier-1 vs tier-2 databases.
2. Map each HA component owner on diagram.
3. Automate archiver and slot lag alerts.
4. Add cross-region async replica RPO documentation.
5. Chaos: fill disk on primary in staging observe alerts.

Remember

Enterprise HA = tech + process + measured targets. Slots, archiver, and lag are early warning. Runbooks beat adrenaline at 3 AM.

PostgresVerse enterprise sign-off

Architecture review validates sync replica, PITR, Patroni, quarterly drills, and on-call runbook.

Outcome: CISO approves payment data on PostgreSQL cluster.