'Get all performance counters for calculating node utilization.'

def _get_node_utilization_counters(self):

    try:
        return ((self._get_node_utilization_system_counters() + self._get_node_utilization_wafl_counters()) + self._get_node_utilization_processor_counters())
    except netapp_api.NaApiError:
        LOG.exception('Could    not    get    utilization    counters    from    node    %s', self.node_name)
        return None
