Get metrics related to YARN nodes

def _yarn_node_metrics(self, rm_address, instance, addl_tags):
        """
        Get metrics related to YARN nodes
        """
        metrics_json = self._rest_request_to_json(rm_address, instance, YARN_NODES_PATH, addl_tags)

        if metrics_json and metrics_json['nodes'] is not None and metrics_json['nodes']['node'] is not None:

            for node_json in metrics_json['nodes']['node']:
                node_id = node_json['id']

                tags = ['node_id:{}'.format(str(node_id))]
                tags.extend(addl_tags)

                self._set_yarn_metrics_from_json(tags, node_json, YARN_NODE_METRICS)