We as an Integrator are new to using Ignition and would like to know if anyone has experience with our redundancy scenario.
We have 2 servers set up as a redundant pair each with a PostgrSQL database running. If the connection to the database failes on the master gateway - we would like the backup to take over and become active.
Is there somewhere to configure this setting?
Thanks in advance.
No, nothing like this exists.
I suggest you handle database redundancy external to Ignition. Host the database on its own server(s), using your database of choice's replication/redundancy mechanism. It should appear and be configured as a single connection to Ignition.
This is how a customer of ours does it with SQL Servers and a Availability Group. They create one "listener port" that Ignition connects to, so we only have one db connection to it, but behind that connection port, they have a redundant pair of database servers that failover as needed.
If you wish to follow Kevin's advice, and don't want to pay EnterpriseDB to set it up for you, look at PostgreSQL's Replication Manager and Backup and Recovery Manager tools.
PostgreSQL can do replication natively, but it doesn't have built-in tools to manage failover. Theoretically, you could script it all yourself with HAProxy or something similar, but repmgr and barman are well-known and supportable tools.
(EnterpriseDB offers support for PostgreSQL and these tools. EDB is the largest employer of contributors to these projects, IIRC.)