Confirm the prerequisites of setup EM in HA scenario

[SAPSupport]

We are referring below link for High Availability Setup for Introscope Enterprise Manager:

For the Prerequisites point 4, it mentions The agents on-the-fly feature is enabled, I don't undestand why this is prerequisites to setup EM HA, it is only one configuration in solman managed system configuration as per my understanding. Would you please clarify on this?
Also for the agents on-the-fly feature, I think it should be enabled for for the HA cluster environment, including solman and managed systems, would you please confirm on this?

Thanks

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[SAPSupport · Accepted solution]

Dear Customer,

For the Introscope EM in HA scenario, Agent on-the-fly is required. After you enabled the Agent on-the-fly, agent node will be generated for logical hostname should be generated, and it should be used for discovering Introscope EM in step Define CA Introscope. When the Introscope EM is switched from host A to host B, the agent failover will be done with it.

For the Agent on-the-fly, it should be done for the Introscope hosts(where the Introscope EM is installed). If the Solution Manager system is in the same hosts/HA scenario with Introscope EM, then the Agent on-the-fly should be enabled for each hosts.
For more details about Agent on-the-fly, please refer to the documentation below:
https://wiki.scn.sap.com/wiki/display/SMSETUP/Diagnostics+Agent+and+HA+Support

 
And about the managed systems(like ECC or S4) which are in HA scenario, it is highly recommended to activate Agent on-the-fly. Because when you perform a failover in HA scenario, the system will be switched with logical hostname from one physical/virtual host to another host. After you enabled the Agent on-the-fly, the agent node of the logical hostname will be switched easily. If Agent on-the-fly is not used, the data collection will be interrupted after failover. And after you switched the logical host from one physical/virtual host to another one, you need to execute all configurations on the second host from the beginning.

Best regards,
Haterm