We are trying to install Admin servers in Active passive mode in a single domain to manage single set of managed servers (for OAM component). The scenerio is that I have Admin Server + Managed Server on OAMHOST1 and OAMHOST2 both. I can start Admin server on OAMHOST1 and then manage both the managed servers on OAMHOST1 and OAMHOST2. Now in case my Admin Server on OAMHOST1 goes down, the requirement is that secondary Admin Server on OAMHOST2 should be started and use to manage the managed servers on OAMHOST1 and OAMHOST2. So i have stopped the admin server on OAMHOST1 and then tried to start the Admin Server on OAMHOST2 but its not starting up. It is simply throwing the error that port 7001 on OAMHOST1 is in use but i can clearly see that there is no service running on 7001 port on OAMHOST1 and ALSO why its trying to connect OAMHOST1:7001. As per oracle documentation this is feasible (this is mentioned in their HA guide) but they haven't mentioned any step to configure this or test this.
Please advise if anyone has any idea to implement this. Since OAM admin is deployed on Admin server, the HA is crucial for Admin Server unavailability.
From your note, I think OAMHOST1 and OAMHOST2 are physical hostnames of the server. You need to create one virtual ip which will be listened from both the physical servers and change the listen address for admin server to this VIP. Please see below mentioned link. Also there is requirement of shared directory, for that you can refer to the enterprise deployment guide for identity management.