docs-v2/content/flux/v0.x/stdlib/universe/statetracking.md

---
title: stateTracking() function
description: >
  `stateTracking()` returns the cumulative count and duration of consecutive
  rows that match a predicate function that defines a state.
menu:
  flux_0_x_ref:
    name: stateTracking
    parent: universe
    identifier: universe/stateTracking
weight: 101
flux/v0.x/tags: [transformations]
introduced: 0.7.0
---

<!------------------------------------------------------------------------------

IMPORTANT: This page was generated from comments in the Flux source code. Any
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To make updates to this documentation, update the function comments above the
function definition in the Flux source code:

https://github.com/influxdata/flux/blob/master/stdlib/universe/universe.flux#L2560-L2570

Contributing to Flux: https://github.com/influxdata/flux#contributing
Fluxdoc syntax: https://github.com/influxdata/flux/blob/master/docs/fluxdoc.md

------------------------------------------------------------------------------->

`stateTracking()` returns the cumulative count and duration of consecutive
rows that match a predicate function that defines a state.

To return the cumulative count of consecutive rows that match the predicate,
include the `countColumn` parameter.
To return the cumulative duration of consecutive rows that match the predicate,
include the `durationColumn` parameter.
Rows that do not match the predicate function `fn` return `-1` in the count
and duration columns.

##### Function type signature

```js
(
    <-tables: stream[A],
    fn: (r: A) => bool,
    ?countColumn: string,
    ?durationColumn: string,
    ?durationUnit: duration,
    ?timeColumn: string,
) => stream[B] where A: Record, B: Record
```

{{% caption %}}For more information, see [Function type signatures](/flux/v0.x/function-type-signatures/).{{% /caption %}}

## Parameters

### fn
({{< req >}})
Predicate function to determine state.



### countColumn

Column to store state count in.

If not defined, `stateTracking()` does not return the state count.

### durationColumn

Column to store state duration in.

If not defined, `stateTracking()` does not return the state duration.

### durationUnit

Unit of time to report state duration in. Default is `1s`.



### timeColumn

Column with time values used to calculate state duration.
Default is `_time`.



### tables

Input data. Default is piped-forward data (`<-`).




## Examples

- [Return a cumulative state count](#return-a-cumulative-state-count)
- [Return a cumulative state duration in milliseconds](#return-a-cumulative-state-duration-in-milliseconds)
- [Return a cumulative state count and duration](#return-a-cumulative-state-count-and-duration)

### Return a cumulative state count

```js
data
    |> stateTracking(fn: (r) => r.state == "crit", countColumn: "count")

```

{{< expand-wrapper >}}
{{% expand "View example input and output" %}}

#### Input data

| _time                | _value  | *tag | state  |
| -------------------- | ------- | ---- | ------ |
| 2021-01-01T00:00:00Z | -2      | t1   | ok     |
| 2021-01-01T00:00:10Z | 10      | t1   | crit   |
| 2021-01-01T00:00:20Z | 7       | t1   | crit   |
| 2021-01-01T00:00:30Z | 17      | t1   | crit   |
| 2021-01-01T00:00:40Z | 15      | t1   | crit   |
| 2021-01-01T00:00:50Z | 4       | t1   | ok     |

| _time                | _value  | *tag | state  |
| -------------------- | ------- | ---- | ------ |
| 2021-01-01T00:00:00Z | 19      | t2   | crit   |
| 2021-01-01T00:00:10Z | 4       | t2   | ok     |
| 2021-01-01T00:00:20Z | -3      | t2   | ok     |
| 2021-01-01T00:00:30Z | 19      | t2   | crit   |
| 2021-01-01T00:00:40Z | 13      | t2   | crit   |
| 2021-01-01T00:00:50Z | 1       | t2   | ok     |


#### Output data

| _time                | _value  | *tag | state  | count  |
| -------------------- | ------- | ---- | ------ | ------ |
| 2021-01-01T00:00:00Z | -2      | t1   | ok     | -1     |
| 2021-01-01T00:00:10Z | 10      | t1   | crit   | 1      |
| 2021-01-01T00:00:20Z | 7       | t1   | crit   | 2      |
| 2021-01-01T00:00:30Z | 17      | t1   | crit   | 3      |
| 2021-01-01T00:00:40Z | 15      | t1   | crit   | 4      |
| 2021-01-01T00:00:50Z | 4       | t1   | ok     | -1     |

| _time                | _value  | *tag | state  | count  |
| -------------------- | ------- | ---- | ------ | ------ |
| 2021-01-01T00:00:00Z | 19      | t2   | crit   | 1      |
| 2021-01-01T00:00:10Z | 4       | t2   | ok     | -1     |
| 2021-01-01T00:00:20Z | -3      | t2   | ok     | -1     |
| 2021-01-01T00:00:30Z | 19      | t2   | crit   | 1      |
| 2021-01-01T00:00:40Z | 13      | t2   | crit   | 2      |
| 2021-01-01T00:00:50Z | 1       | t2   | ok     | -1     |

{{% /expand %}}
{{< /expand-wrapper >}}

### Return a cumulative state duration in milliseconds

```js
data
    |> stateTracking(fn: (r) => r.state == "crit", durationColumn: "duration", durationUnit: 1ms)

```

{{< expand-wrapper >}}
{{% expand "View example input and output" %}}

#### Input data

| _time                | _value  | *tag | state  |
| -------------------- | ------- | ---- | ------ |
| 2021-01-01T00:00:00Z | -2      | t1   | ok     |
| 2021-01-01T00:00:10Z | 10      | t1   | crit   |
| 2021-01-01T00:00:20Z | 7       | t1   | crit   |
| 2021-01-01T00:00:30Z | 17      | t1   | crit   |
| 2021-01-01T00:00:40Z | 15      | t1   | crit   |
| 2021-01-01T00:00:50Z | 4       | t1   | ok     |

| _time                | _value  | *tag | state  |
| -------------------- | ------- | ---- | ------ |
| 2021-01-01T00:00:00Z | 19      | t2   | crit   |
| 2021-01-01T00:00:10Z | 4       | t2   | ok     |
| 2021-01-01T00:00:20Z | -3      | t2   | ok     |
| 2021-01-01T00:00:30Z | 19      | t2   | crit   |
| 2021-01-01T00:00:40Z | 13      | t2   | crit   |
| 2021-01-01T00:00:50Z | 1       | t2   | ok     |


#### Output data

| _time                | _value  | *tag | state  | duration  |
| -------------------- | ------- | ---- | ------ | --------- |
| 2021-01-01T00:00:00Z | -2      | t1   | ok     | -1        |
| 2021-01-01T00:00:10Z | 10      | t1   | crit   | 0         |
| 2021-01-01T00:00:20Z | 7       | t1   | crit   | 10000     |
| 2021-01-01T00:00:30Z | 17      | t1   | crit   | 20000     |
| 2021-01-01T00:00:40Z | 15      | t1   | crit   | 30000     |
| 2021-01-01T00:00:50Z | 4       | t1   | ok     | -1        |

| _time                | _value  | *tag | state  | duration  |
| -------------------- | ------- | ---- | ------ | --------- |
| 2021-01-01T00:00:00Z | 19      | t2   | crit   | 0         |
| 2021-01-01T00:00:10Z | 4       | t2   | ok     | -1        |
| 2021-01-01T00:00:20Z | -3      | t2   | ok     | -1        |
| 2021-01-01T00:00:30Z | 19      | t2   | crit   | 0         |
| 2021-01-01T00:00:40Z | 13      | t2   | crit   | 10000     |
| 2021-01-01T00:00:50Z | 1       | t2   | ok     | -1        |

{{% /expand %}}
{{< /expand-wrapper >}}

### Return a cumulative state count and duration

```js
data
    |> stateTracking(fn: (r) => r.state == "crit", countColumn: "count", durationColumn: "duration")

```

{{< expand-wrapper >}}
{{% expand "View example input and output" %}}

#### Input data

| _time                | _value  | *tag | state  |
| -------------------- | ------- | ---- | ------ |
| 2021-01-01T00:00:00Z | -2      | t1   | ok     |
| 2021-01-01T00:00:10Z | 10      | t1   | crit   |
| 2021-01-01T00:00:20Z | 7       | t1   | crit   |
| 2021-01-01T00:00:30Z | 17      | t1   | crit   |
| 2021-01-01T00:00:40Z | 15      | t1   | crit   |
| 2021-01-01T00:00:50Z | 4       | t1   | ok     |

| _time                | _value  | *tag | state  |
| -------------------- | ------- | ---- | ------ |
| 2021-01-01T00:00:00Z | 19      | t2   | crit   |
| 2021-01-01T00:00:10Z | 4       | t2   | ok     |
| 2021-01-01T00:00:20Z | -3      | t2   | ok     |
| 2021-01-01T00:00:30Z | 19      | t2   | crit   |
| 2021-01-01T00:00:40Z | 13      | t2   | crit   |
| 2021-01-01T00:00:50Z | 1       | t2   | ok     |


#### Output data

| _time                | _value  | *tag | state  | count  | duration  |
| -------------------- | ------- | ---- | ------ | ------ | --------- |
| 2021-01-01T00:00:00Z | -2      | t1   | ok     | -1     | -1        |
| 2021-01-01T00:00:10Z | 10      | t1   | crit   | 1      | 0         |
| 2021-01-01T00:00:20Z | 7       | t1   | crit   | 2      | 10        |
| 2021-01-01T00:00:30Z | 17      | t1   | crit   | 3      | 20        |
| 2021-01-01T00:00:40Z | 15      | t1   | crit   | 4      | 30        |
| 2021-01-01T00:00:50Z | 4       | t1   | ok     | -1     | -1        |

| _time                | _value  | *tag | state  | count  | duration  |
| -------------------- | ------- | ---- | ------ | ------ | --------- |
| 2021-01-01T00:00:00Z | 19      | t2   | crit   | 1      | 0         |
| 2021-01-01T00:00:10Z | 4       | t2   | ok     | -1     | -1        |
| 2021-01-01T00:00:20Z | -3      | t2   | ok     | -1     | -1        |
| 2021-01-01T00:00:30Z | 19      | t2   | crit   | 1      | 0         |
| 2021-01-01T00:00:40Z | 13      | t2   | crit   | 2      | 10        |
| 2021-01-01T00:00:50Z | 1       | t2   | ok     | -1     | -1        |

{{% /expand %}}
{{< /expand-wrapper >}}