PostgreSQL Logical Replication Lag: Big Transactions and Reorder Buffer Spills
One huge transaction can pin logical replication for hours. Runbook to detect the blocker, tune decoding safely, and enforce bounded transactions in prod.
#replication
5 posts
hot_standby_feedback Bloat Trap: Fixing Replica Conflicts by Slowly Killing the Primary
hot_standby_feedback stops replica query cancellations but can bloat the primary over days. Detect xmin pinning, mitigate safely, and add guardrails.
Logical Replication Slot WAL Bloat: When Subscribers Go Offline
Disk filling up with WAL files. The cause: a logical replication slot consumer went offline, and PostgreSQL retains all WAL since then because it might be needed.
PostgreSQL Replication Slot Bloat: How One Inactive Slot Filled 500GB Disk
Disk is 95% full, WAL directory has 400GB. I'll show how replication slots prevent WAL cleanup and a playbook for prevention and recovery.
PostgreSQL Read Replica Conflicts: Why Your Queries Get Canceled
Queries on read replicas fail with 'canceling statement due to conflict with recovery'. The fix depends on which of the 5 conflict types you have - here's how to diagnose and solve each one.