PostgreSQL 12 High Availability Cookbook - Third Edition

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If you'd like to read ahead, in Chapter 4, Proxy and Pooling Resources, we explain how to simplify this even further. The process is the same until the final few steps, where applications reconnect to the database. If applications and users are using a virtual address instead of the actual server IP for the old database, they can continue to use the virtual location after the migration.

Simply detach the virtual IP from the old database server and attach it to the new one before informing the users that the migration is complete. As an added benefit, we can use the virtual IP address as a form of security. Until we create it, users will be unable to locate the database. We can take advantage of this and perform database checks ...