def _set_metric(self, metric_name, metric_type, value, tags=None):
        """
        Set a metric
        """
        if tags is None:
            tags = []
        if metric_type == GAUGE:
            self.gauge(metric_name, value, tags=tags)
        elif metric_type == COUNT:
            self.count(metric_name, value, tags=tags)
        elif metric_type == MONOTONIC_COUNT:
            self.monotonic_count(metric_name, value, tags=tags)
        else:
            self.log.error('Metric type "{}" unknown'.format(metric_type))