Here's the default configuration suggested by the official documentation for High Availability Yarn:
[[[ha]]]
resourcemanager_host=<second_resource_manager_host_FQDN>
resourcemanager_api_url=http://<second_resource_manager_host_URL>
proxy_api_url=<second_resource_manager_proxy_URL>
history_server_api_url=<history_server_API_URL>
resourcemanager_port=<port_for_RM_IPC>
security_enabled=false
submit_to=true
logical_name=XXXX