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Topic - High availability

High availability writing.

Notes about failover contracts, fencing, ambiguous time, and the operational details that decide whether recovery is trustworthy.

2026-04-12A failover that waited 480 ms longer than plannedThe cluster worked. The service recovered. The ugly part was the half second nobody had budgeted for.High availability6 min

2026-05-20Pacemaker vs Patroni for PostgreSQL high availabilityA practical comparison of Pacemaker and Patroni for PostgreSQL failover, with tradeoffs around fencing, consensus, routing, operations, and recovery.High availability18 min

2026-05-21PostgreSQL failover checklist before maintenanceA practical PostgreSQL failover checklist for maintenance windows: replication lag, fencing assumptions, client routing, rollback conditions, and proof of recovery.High availability9 min