Interface switching speed

I do a test of switching between the master PC and the backup PC interface, but if I disconnect the master PC, it takes a long time to switch the interface to the backup PC. It's about two minutes, and when you reconnect, it's fast to recover to the master PC interface. And as you switch, you lose about 2 to 10 seconds of lost data.
I'd appreciate it if you could tell me how to improve the speed of interface switching and how to make sure there's no lost data.

You can try changing the standby activity level to warm. However understand that this will increase the load on every PLC as all the connections will be active from both servers.

The activity level is already in a warm state. Is there any other way?...

When you say you are missing data, what do you mean? What part of the system is missing data? That will help us narrow things down for you to try.

Yes, you will lose some data. Ignition is not 100% uptime "hot" redundancy. There is a setting for the time delay on the backup after it loses comms with the master before it declares it "dead" and takes over. During that total time, PLC samples aren't being collected.

If there is data in the PLCs that you absolutely cannot lose, then you will need to buffer it in the PLC with logic, and use handshakes with Ignition to confirm delivery to your database.