Hello!
First of all, let me state that I am no senior InterSystems expert.
In my organization, we have a HealthShare Health Connect setup where each namespace has one code database and one data database, which are both actively mirrored. We have two nodes in the mirror.
We had a controlled failover last night to make sure that the backup node works as intended, which it didn't.It turned out that we had only deployed code onto the primary node in several namespaces causing errors with missing classes after the failover.