Set thresholds to highlight metric values that are outside normal operating ranges. Set maximum vertical axis ranges to limit the range of values displayed for selected metrics. After a metric threshold is set in the Settings view, the threshold line is displayed across the graph with the threshold value to the right of the graph when you select a metric plot line. As you hover over the selected plot line, information balloons display the data point value and the minimum and maximum performance envelope values. The plot line and information balloons change to red when the threshold is exceeded during the time frame. Threshold settings are optional and can be set any time after the metric has been configured.