I was looking through the docs for Ignition 8.1 and it seems that OPC UA Server Redundancy is now supported but I've had no luck getting it working so far. The specific issue I'm running into is the client doesn't like the URN returned by the server in the redundant server set array; it's expecting a normal opc.tpc endpoint, but instead Ignition returns the server URN.
I'm imagining I'm doing something wrong, so I'm going to take a look through the docs again -- but wanted to check here and ask if anyone has had any success getting server redundancy set up and using third party OPC UA clients.
So, just to be clear, all that really changed is that the server publishes that it only supports non-transparent redundancy, and now sets the ServiceLevel and ServerUriArray values as appropriate.
This client is broken. The redundant server set is a set of URIs, not endpoint URLs. It's the responsibility of the client to be able to map these to endpoint URLs. Servers are identified by a URI in the discovery services, so a client can either be configured with the mapping ahead of time or figure it out using discovery services.
In theory, OPC UA redundancy works best when using a centralized discovery server of some kind, but this practice hasn't really taken off quite yet. There are commercial GDS (Global Discovery Server) products starting to hit the market now so hopefully we see this become more common. If all servers support registration and there's a central discovery server, the Server URI lookup becomes a lot easier.