calc_slope.py

    def calc_slope(self, minuets):
        """
        Calculate the slope of available memory change.

        :param: minuets how long to go back in time
        """

        met = metrics.Metrics(self.cluster_name)
        series = met.read_timeseries('YARNMemoryAvailablePercentage', minuets)
        retlist = []
        x = []
        y = []
        retlist.extend(series[0]['points'])
        i = len(retlist)
        for rl in retlist:
            x.insert(0, rl['value']['doubleValue'])
            y.insert(0, i)
            i = i - 1
        try:
            slope, intercept = np.polyfit(x, y, 1)
            logging.debug('Slope is %s', slope)
        except np.RankWarning:
            # not enough data so add remove by 2
            if self.scaling_direction == 'up':
                slope = 1
            else:
                slope = -1
            logging.debug('No Data slope is %s', slope)

        return slope