Recovery Question in OPS

Hi

I have a Node 1 and a Node 2 . I am running Oracle Parallel server . The 2 instances are called prod1 and prod2.
PROD1 has 3 redologs and also prod2 has 3 redologs with thread1 and thread 2.

My question is if PROD1 instance crashes and I failover to PROD2 . what happens to the redologs of PROD1. how are they read and what happens to all the transactions in them .

How do I recover redologs of thread1 when I failover to instance 2 having its own redologs of thread 2.

Thanks

Instance 2 will read redologs of Thread 1. so you have to place redolog file in a shared disk.