PostgreSQL HA Risks, Replication Internals, & Rapid Branching

PostgreSQL HA Risks, Replication Internals, & Rapid Branching Today's Highlights Today's highlights include critical insights into Patroni's replication slot management, an architectural deep dive into PostgreSQL's synchronous commit behavior, and a look at achieving sub-second database branching for enhanced developer workflows. When Patroni Silently Deletes Your Replication Slots (Planet PostgreSQL) Source: https://postgr.es/p/9lM This article uncovers a critical operational pitfall when using Patroni, a popular high-availability solution for PostgreSQL, with logical replication. It details how Patroni, under specific failure scenarios or configuration changes, can silently remove replication slots without warning. Replication slots are vital for ensuring that standbys or logical replication consumers do not miss any changes, making their deletion a potentially severe data integrity issue. The author explains the underlying reasons for this behavior, often related to how Patroni manages pg_basebackup or restores, and how it might not re-create logical replication slots automatically. The post provides concrete scenarios where this can occur, such as when a new primary is elected and old slots aren't re-established, or during certain recovery operations. It emphasizes the importance of diligent monitoring of replication slot status and proposes strategies to mitigate the risk of silent deletion, including careful Patroni configuration and robust alerting mechanisms. This insight is crucial for database administrators and developers relying on Patroni for resilient PostgreSQL deployments, highlighting a subtle but dangerous interaction between these two powerful components. Comment: This is a must-read for anyone running Patroni with PostgreSQL, especially if using logical replication. Understanding this specific behavior of Patroni deleting replication slots silently is essential to prevent unexpected data loss or integrity issues in production. Why Postgres Doesn'