PostgreSQL Streaming Standby Creation

Replication / Guide 27 of 47 / Advanced

• OSUbuntu 26.04 LTS
• PostgreSQL18.6-0ubuntu0.26.04.1
• ReplicationPhysical streaming, async, with slots
• TimeAbout 17 min

standby.signal replaced recovery.conf in PostgreSQL 12. Documentation mentioning recovery.conf is describing a file that no longer exists.

This guide includes

Use this when a streaming standby has to exist. This matters because one pg_basebackup -R copies the cluster, writes its connection settings and marks it as a standby - and the standby then refuses writes, which is the proof it worked.

• emptying the standby, and copying the primary onto it
• seeing the two things that one -R flag wrote for you
• starting it, and confirming what Debian reports it as
• proving replication, then trying to write and being refused

Before you start

• The prerequisites guide completed - role, rule and slot.
• A second host whose data you are willing to destroy.

1. 1

   Empty the standby and copy the primary onto it

2. 2

   See what -R wrote

3. 3

   Start it and confirm what it is

4. 4

   Prove replication, then try to write

Official sources

• PostgreSQL 18 Documentation - High Availability and Replication
• PostgreSQL 18 Documentation - Setting Up a Standby Server
• PostgreSQL 18 Documentation - Replication Slots
• PostgreSQL 18 Documentation - pg_stat_replication
• PostgreSQL 18 Documentation - Failover and Timelines