PostgreSQL 12 High Availability Cookbook - Third Edition

How to do it…

Assuming we have our old server (pg-old) and a new server (pg-new) to act as the subscriber, follow these instructions to start the subscription:

1. Execute the following query on pg-new to initiate the subscription:

SELECT pglogical.create_subscription(    subscription_name := 'myapp_upgrade',    provider_dsn := 'host=pg-old dbname=myapp user=rep_user');

2. Wait for the subscription to complete by executing this query on pg-new:

SELECT pglogical.wait_for_subscription_sync_complete(    'myapp_upgrade');

3. Check for the following line in the pg-new PostgreSQL log:

LOG:  starting apply for subscription myapp_upgrade

4. Check for the following line in the pg-old PostgreSQL log:

LOG:  exported logical decoding snapshot