PostgreSQL 12 High Availability Cookbook - Third Edition

How it works...

The first step is clearly the most critical. We need to determine which node has the most recent valid data. In almost all cases, there should be sufficient logs to make this determination. However, in some network disruption scenarios coupled with automated failover solutions, this may not be obvious. Unfortunately, resolving this step is too varied to adequately express in a simple guide.

If you are unsure of how to continue following an extremely complicated failure scenario, we strongly recommend contacting Linbit, which maintains the DRBD software. Their support information is available at https://www.linbit.com/en/support/.

For our example, we manually promoted the pg2 node, so it should be the new primary. With that ...