We have a system with 2 central Ignition gateways participating in redundancy. We have several Edge gateways connecting to the active node via OPC-UA. What is the best way to redirect the OPC-UA connections on the Edge gateways to the alternative node if the active gateway goes down ?
Is there a way to monitor the [System]Gateway/Redundancy/Role central gateway tag from the Edge gateway ?
First of all, I think it would be easier on the Central gateway to just use remote tag providers pointing to your Edge Gateways rather than OPC Connections. The remote tag provider engine is designed to be used in this scenario, whereas OPC connections are typically for 3rd party OPC Servers. Those remote tag providers will automatically be available on both Master and Backup Central Gateway.
That being said, if you did want to stick with OPC connections, all you should need to do would be to setup the Failover settings on your OPC Client Connection on the Edge side, following this manual page.