delta Metrics Operator

The delta operator computes the backward difference at each data point in the time series to determine how much the metric has changed from its last value in the series.

The delta operator updates the metric dimension, if present, to delta($metric). If the original time series does not have a metric dimension, it creates metric=delta dimension. Other dimensions remain unaffected.

You can use the increasing or decreasing option, to make delta consider only pairs of consecutive points where the second point is greater or less than the first point. This functionality is useful when you are calculating the positive or the negative difference of a counter over time.

delta syntax

metric query | delta [increasing | decreasing]

delta examples

Difference in a metric value from previous point

This query returns a time series that reflects the difference in the Net_InBytes metric for the eth0 interface between a charted value and the one preceding it.

metric=Net_InBytes Interface=eth0 | delta

Positive difference in a metric over time

This query returns a time series that reflects the difference in the elasticsearch_jvm_mem_heap_used_in_bytes metric between a charted value and the one preceding it, only considering pairs of consecutive points where the second point is greater than the first point.

metric=elasticsearch_jvm_mem_heap_used_in_bytes | delta increasing