3.2.6 Consolidation display of trend data with dynamic range vectors
When specifying a range vector in promql of metric definition file, specify "$stepTime{minSeconds="minimum-seconds"}" or a fixed value for the range vector selector (the value specified in square brackets [ ]). If you specify anything else that cannot be interpreted as PromQL expression, the panel is not displayed. For minimum-seconds, specify a positive integer.
When "$stepTime{minSeconds="minimum-seconds"}" is specified for the range vector selector, the trend data is dynamically calculated and displayed for the range vector so that all data is included according to the displayed range of the trend data in the dashboard. These are the dashboard panels (Trends, Ranks, Numbers, Gauges) and the trend data you want to view in trend data display function.
For details about trend data display function, see Consolidation display of trend data with dynamic range vectors in 3.15.6(4)(c) About Performance Data to Retrieve. Also, for the procedure for checking graphs of metrics that detected anomalies in alerts when a fixed value is specified or "$stepTime{minSeconds="minimum-seconds"} is specified for the range vector selector in the metric definition file, see Consolidation display of trend data with dynamic range vectors in 3.15.6(4)(c) About Performance Data to Retrieve.
When the trend data is acquired, "$stepTime{minSeconds="minimum-seconds"}" is replaced with the time calculated by the following formula.
If the value obtained by the calculation formula is a decimal, the fractional part is truncated to an integer.
Trend data acquisition range (seconds) / (number of plots - 1)
However, if the value obtained by the calculation expression is smaller than the value specified by minimum-seconds, "$stepTime{minSeconds="minimum-seconds"}" is replaced with the time specified by minimum-seconds.