PostgreSQL 12 High Availability Cookbook - Third Edition

How to do it...

For this recipe, we should already have three PostgreSQL servers. As usual, we'll assume they are named pgha1, pgha2, and pgha3. If pgha1 is the current primary, follow these steps to switch to ZooKeeper:

1. Locate the myid file in the ZooKeeper configuration directory for each server. This is usually /etc/zookeeper/conf. It should contain a single-digit number. Keep this for reference.
2. Assuming the server number in myid corresponds to the server name we've assigned (pgha1 and so on), ensure the zoo.cfg configuration file on each server contains the following lines:

server.1=pgha1:2888:3888 
server.2=pgha2:2888:3888 
server.3=pgha3:2888:3888 

3. If necessary, reload the ZooKeeper configuration file with the following command: