Setting Up Failover Slots in PostgreSQL-17
PostgreSQL 17 introduces failover slots that enhance high-availability setups. A replication slot ensures that data remains reliable and consistent between nodes during replication, whereas a failover slot ensures consistency between nodes, specifically during and after a failover.
Failover slots are a powerful feature that ensures logical replication can continue seamlessly, even after a failover to a standby server. Using failover slots allows logical replication slots to be automatically synchronized across primary and standby nodes, significantly reducing downtime and the need for manual intervention during a failover.
This guide will walk you through setting up a high-availability PostgreSQL cluster using the new failover slots feature. By the end, you'll have a robust replication setup capable of seamlessly handling a failover.
Replication Slots Tied to the Primary Node: In PostgreSQL 15, replication slots were only created on the primary server. All logical replication slots were lost if the primary server failed, leading to significant replication delays and data loss.
