On my MapR-5.2 version 7 node cluster, stand by resource manager is down with this error on HUE,
Failed to contact an active Resource Manager: YARN RM returned a failed response: HTTPConnectionPool(host='SAN2LPMR02.', port=8088): Max retries exceeded with url: /ws/v1/cluster/apps?user=mapr (Caused by NewConnectionError(': Failed to establish a new connection: [Errno 111] Connection refused',))
and also please find the attached for Resource manager log.
Really appreciate your assistance to resolve this issue.