We have a validated 3-tier system (Client, Application server and DB).
Now we are planning to introduce a secondary Application server in the system. This secondary Application server will be identical to the primary server.
Note: We will be using a load balancer which will include the two Application servers.
Now the question is how much validation is needed to validate the secondary server in the system? I think the full validation that was done for the system with the primary server is not needed. Any thoughts?