postgresql-replication

name	postgresql-replication
description	PostgreSQL streaming replication - setup, monitoring, failover
version	3.0.0
sasmp_version	1.3.0
bonded_agent	08-postgresql-devops
bond_type	SECONDARY_BOND
category	database
difficulty	advanced
estimated_time	4h

PostgreSQL Replication Skill

Atomic skill for streaming replication

Overview

Production-ready patterns for streaming replication, monitoring, and failover with Patroni.

Prerequisites

• PostgreSQL 16+
• Multiple server nodes
• Network connectivity

Parameters

parameters:
  operation:
    type: string
    required: true
    enum: [setup_primary, setup_replica, monitor, failover]
  replication_mode:
    type: string
    enum: [async, sync]
    default: async

Quick Reference

Primary Setup

-- postgresql.conf
wal_level = replica
max_wal_senders = 10
max_replication_slots = 10

-- Create replication user
CREATE ROLE replicator WITH REPLICATION LOGIN PASSWORD 'secret';

-- Create slot
SELECT pg_create_physical_replication_slot('replica1');

Replica Setup

pg_basebackup -h primary -D /data -U replicator -v -P -R

Monitor Lag

-- On primary
SELECT client_addr, state,
    pg_size_pretty(pg_wal_lsn_diff(sent_lsn, replay_lsn)) as lag
FROM pg_stat_replication;


 pg_is_in_recovery(), pg_last_wal_replay_lsn();