# Incremental Sum (`incremental_sum`) This modules finds the incremental sum of a period, which `last value - first value`. The result may be positive (rising) or negative (falling) depending on the first and last values. ## how to use Use it in alarms like this: ``` alarm: my_alarm on: my_chart lookup: incremental_sum -1m unaligned of my_dimension warn: $this > 1000 ``` `incremental_sum` does not change the units. For example, if the chart units is `requests/sec`, the result will be again expressed in the same units. It can also be used in APIs and badges as `&group=incremental_sum` in the URL. ## Examples Examining last 1 minute `successful` web server responses: -  -  -  -  ## References - none