docs-v2/content/v2.0/reference/flux/functions/built-in/transformations/statecount.md

title	description	aliases	menu	weight
stateCount() function	The `stateCount()` function computes the number of consecutive records in a given state.	/v2.0/reference/flux/functions/transformations/statecount	v2_0_ref name parent stateCount built-in-transformations	401

The stateCount() function computes the number of consecutive records in a given state. The state is defined via the function fn. For each consecutive point that evaluates as true, the state count is incremented. When a point evaluates as false, the state count is reset. The state count is added as an additional column to each record.

Function type: Transformation
Output data type: Integer

stateCount(fn: (r) => r._field == "state", column: "stateCount")

If the expression generates an error during evaluation, the point is discarded and does not affect the state count.

Parameters

{{% note %}} Make sure fn parameter names match each specified parameter. To learn why, see Match parameter names. {{% /note %}}

fn

A single argument function that evaluates true or false to identify the state of the record. Records are passed to the function. Those that evaluate to true increment the state count. Those that evaluate to false reset the state count.

Data type: Function

column

The name of the column added to each record that contains the incremented state count.

Data type: String

Examples

from("monitor/autogen")
  |> range(start: -1h)
  |> filter(fn: (r) => r._measurement == "http")
  |> stateCount(
    fn: (r) => r.http_response_code == "500",
    column: "server_error_count"
  )