If you are using OS clustering, the RA Retail agent should be installed on the clustered file system. In a fall-over situation, the cluster file system and service IP will be moved by the OS from the fail node to the standby node. Then, the cluster service will start the application services on the standby node making it active. The start sequence for the RA Retail agent should be a service in the cluster application service.
Another way to do it would be to install the RA Retail agent on the local file system. Then, you would have 2 RA Retail agent in an Automic Agent Group. Then, you would assign all the Retail job to that group. Using this scenario, you will not have to deal with the OS cluster, Cluster service IP and file system. You must ensure that the workflows does not have re-use agent calculation in the Attributes tab.