I have a highly available distributed application which already provides a single point of access to configuration and run-time state information for the resources that comprise and are managed by the application where these resources are scattered across numerous nodes/hosts. This single point of access has HA characteristics in the sense that if the node/host where access to resource information is being provided fails then another node/host takes over providing access to the same resource information.
I want to manage such a logical resource through Enterprise Manager by creating a single target instance and somehow have OEM know which host/node to go through to access the target's configuration and run-time state. Is this possible with OEM? So for example if I have a target X that represents a logical resource that doesn't reside on any particular node/host and initially node A acts as the host for target X. But if node A were to fail, node B would take over and provide access to target X. Can OEM be directed to associate node B as the host for target X after such a failure?
Several possibilities I see are:
1. Floating/virtual IP address
Can I use a floating/virtual IP address in place of the host name when creating such a target in OEM that would point OEM to the current active host/node that provides access to the resource? If yes, what, if any, special actions are required to indicate to OEM that a failover has occurred?
2. Dynamically update the host for a target
Can I change the host for a given target dynamically? In this case that would mean I could direct OEM to use a different host/node if there is a change in the host/node providing access to the resource information.