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ported kapacitor 1.4
2020-07-30 16:38:32 +00:00
---
title: StateDurationNode (Kapacitor TICKscript node)
description: StateDurationNode computes the duration of a given state (defined using a lambda expression).
note: Auto generated by tickdoc
menu:
kapacitor_1_4:
name: StateDurationNode
identifier: state_duration_node
weight: 270
parent: TICKscript nodes
---
### Constructor
| Chaining Method | Description |
|:---------|:---------|
| **[stateDuration](#descr) ( `expression` `ast.LambdaNode`)** | Create a node that tracks duration in a given state. |
### Property Methods
| Setters | Description |
|:---|:---|
| **[as](#as) ( `value` `string`)** | The new name of the resulting duration field. Default: 'state_duration' |
| **[unit](#unit) ( `value` `time.Duration`)** | The time unit of the resulting duration value. Default: 1s. |
### Chaining Methods
[Alert](/kapacitor/v1.4/nodes/state_duration_node/#alert), [Barrier](/kapacitor/v1.4/nodes/state_duration_node/#barrier), [Bottom](/kapacitor/v1.4/nodes/state_duration_node/#bottom), [Combine](/kapacitor/v1.4/nodes/state_duration_node/#combine), [Count](/kapacitor/v1.4/nodes/state_duration_node/#count), [CumulativeSum](/kapacitor/v1.4/nodes/state_duration_node/#cumulativesum), [Deadman](/kapacitor/v1.4/nodes/state_duration_node/#deadman), [Default](/kapacitor/v1.4/nodes/state_duration_node/#default), [Delete](/kapacitor/v1.4/nodes/state_duration_node/#delete), [Derivative](/kapacitor/v1.4/nodes/state_duration_node/#derivative), [Difference](/kapacitor/v1.4/nodes/state_duration_node/#difference), [Distinct](/kapacitor/v1.4/nodes/state_duration_node/#distinct), [Ec2Autoscale](/kapacitor/v1.4/nodes/state_duration_node/#ec2autoscale), [Elapsed](/kapacitor/v1.4/nodes/state_duration_node/#elapsed), [Eval](/kapacitor/v1.4/nodes/state_duration_node/#eval), [First](/kapacitor/v1.4/nodes/state_duration_node/#first), [Flatten](/kapacitor/v1.4/nodes/state_duration_node/#flatten), [GroupBy](/kapacitor/v1.4/nodes/state_duration_node/#groupby), [HoltWinters](/kapacitor/v1.4/nodes/state_duration_node/#holtwinters), [HoltWintersWithFit](/kapacitor/v1.4/nodes/state_duration_node/#holtwinterswithfit), [HttpOut](/kapacitor/v1.4/nodes/state_duration_node/#httpout), [HttpPost](/kapacitor/v1.4/nodes/state_duration_node/#httppost), [InfluxDBOut](/kapacitor/v1.4/nodes/state_duration_node/#influxdbout), [Join](/kapacitor/v1.4/nodes/state_duration_node/#join), [K8sAutoscale](/kapacitor/v1.4/nodes/state_duration_node/#k8sautoscale), [KapacitorLoopback](/kapacitor/v1.4/nodes/state_duration_node/#kapacitorloopback), [Last](/kapacitor/v1.4/nodes/state_duration_node/#last), [Log](/kapacitor/v1.4/nodes/state_duration_node/#log), [Max](/kapacitor/v1.4/nodes/state_duration_node/#max), [Mean](/kapacitor/v1.4/nodes/state_duration_node/#mean), [Median](/kapacitor/v1.4/nodes/state_duration_node/#median), [Min](/kapacitor/v1.4/nodes/state_duration_node/#min), [Mode](/kapacitor/v1.4/nodes/state_duration_node/#mode), [MovingAverage](/kapacitor/v1.4/nodes/state_duration_node/#movingaverage), [Percentile](/kapacitor/v1.4/nodes/state_duration_node/#percentile), [Sample](/kapacitor/v1.4/nodes/state_duration_node/#sample), [Shift](/kapacitor/v1.4/nodes/state_duration_node/#shift), [Sideload](/kapacitor/v1.4/nodes/state_duration_node/#sideload), [Spread](/kapacitor/v1.4/nodes/state_duration_node/#spread), [StateCount](/kapacitor/v1.4/nodes/state_duration_node/#statecount), [StateDuration](/kapacitor/v1.4/nodes/state_duration_node/#stateduration), [Stats](/kapacitor/v1.4/nodes/state_duration_node/#stats), [Stddev](/kapacitor/v1.4/nodes/state_duration_node/#stddev), [Sum](/kapacitor/v1.4/nodes/state_duration_node/#sum), [SwarmAutoscale](/kapacitor/v1.4/nodes/state_duration_node/#swarmautoscale), [Top](/kapacitor/v1.4/nodes/state_duration_node/#top), [Union](/kapacitor/v1.4/nodes/state_duration_node/#union), [Where](/kapacitor/v1.4/nodes/state_duration_node/#where), [Window](/kapacitor/v1.4/nodes/state_duration_node/#window)
<a id='descr'/><hr/><br/>
### Description
Compute the duration of a given state.
The state is defined using a lambda expression. For each consecutive point for
which the expression evaluates as true, the state duration will be
incremented by the duration between points. When a point evaluates as false,
the state duration is reset.
The state duration will be added as an additional field to each point. If the
expression evaluates as false, the value will be `-1`. If the expression
generates an error during evaluation, the point is discarded, and does not
affect the state duration.
Example:
```javascript
stream
|from()
.measurement('cpu')
|where(lambda: "cpu" == 'cpu-total')
|groupBy('host')
|stateDuration(lambda: "usage_idle" <= 10)
.unit(1m)
|alert()
// Warn after 1 minute
.warn(lambda: "state_duration" >= 1)
// Critical after 5 minutes
.crit(lambda: "state_duration" >= 5)
```
Note that as the first point in the given state has no previous point, its
state duration will be 0.
<a class="top" href="javascript:document.getElementsByClassName('article-heading')[0].scrollIntoView();" title="top"><span class="icon arrow-up"></span></a>
Properties
----------
Property methods modify state on the calling node.
They do not add another node to the pipeline, and always return a reference to the calling node.
Property methods are marked using the `.` operator.
### As
The new name of the resulting duration field.
Default: 'state_duration'
```javascript
stateDuration.as(value string)
```
<a class="top" href="javascript:document.getElementsByClassName('article-heading')[0].scrollIntoView();" title="top"><span class="icon arrow-up"></span></a>
### Unit
The time unit of the resulting duration value.
Default: 1s.
```javascript
stateDuration.unit(value time.Duration)
```
<a class="top" href="javascript:document.getElementsByClassName('article-heading')[0].scrollIntoView();" title="top"><span class="icon arrow-up"></span></a>
Chaining Methods
----------------
Chaining methods create a new node in the pipeline as a child of the calling node.
They do not modify the calling node.
Chaining methods are marked using the `|` operator.
### Alert
Create an alert node, which can trigger alerts.
```javascript
stateDuration|alert()
```
Returns: [AlertNode](/kapacitor/v1.4/nodes/alert_node/)
<a class="top" href="javascript:document.getElementsByClassName('article-heading')[0].scrollIntoView();" title="top"><span class="icon arrow-up"></span></a>
### Barrier
Create a new Barrier node that emits a BarrierMessage periodically
One BarrierMessage will be emitted every period duration
```javascript
stateDuration|barrier()
```
Returns: [BarrierNode](/kapacitor/v1.4/nodes/barrier_node/)
<a class="top" href="javascript:document.getElementsByClassName('article-heading')[0].scrollIntoView();" title="top"><span class="icon arrow-up"></span></a>
### Bottom
Select the bottom `num` points for `field` and sort by any extra tags or fields.
```javascript
stateDuration|bottom(num int64, field string, fieldsAndTags ...string)
```
Returns: [InfluxQLNode](/kapacitor/v1.4/nodes/influx_q_l_node/)
<a class="top" href="javascript:document.getElementsByClassName('article-heading')[0].scrollIntoView();" title="top"><span class="icon arrow-up"></span></a>
### Combine
Combine this node with itself. The data is combined on timestamp.
```javascript
stateDuration|combine(expressions ...ast.LambdaNode)
```
Returns: [CombineNode](/kapacitor/v1.4/nodes/combine_node/)
<a class="top" href="javascript:document.getElementsByClassName('article-heading')[0].scrollIntoView();" title="top"><span class="icon arrow-up"></span></a>
### Count
Count the number of points.
```javascript
stateDuration|count(field string)
```
Returns: [InfluxQLNode](/kapacitor/v1.4/nodes/influx_q_l_node/)
<a class="top" href="javascript:document.getElementsByClassName('article-heading')[0].scrollIntoView();" title="top"><span class="icon arrow-up"></span></a>
### CumulativeSum
Compute a cumulative sum of each point that is received.
A point is emitted for every point collected.
```javascript
stateDuration|cumulativeSum(field string)
```
Returns: [InfluxQLNode](/kapacitor/v1.4/nodes/influx_q_l_node/)
<a class="top" href="javascript:document.getElementsByClassName('article-heading')[0].scrollIntoView();" title="top"><span class="icon arrow-up"></span></a>
### Deadman
Helper function for creating an alert on low throughput, a.k.a. deadman's switch.
- Threshold -- trigger alert if throughput drops below threshold in points/interval.
- Interval -- how often to check the throughput.
- Expressions -- optional list of expressions to also evaluate. Useful for time of day alerting.
Example:
```javascript
var data = stream
|from()...
// Trigger critical alert if the throughput drops below 100 points per 10s and checked every 10s.
data
|deadman(100.0, 10s)
//Do normal processing of data
data...
```
The above is equivalent to this
Example:
```javascript
var data = stream
|from()...
// Trigger critical alert if the throughput drops below 100 points per 10s and checked every 10s.
data
|stats(10s)
.align()
|derivative('emitted')
.unit(10s)
.nonNegative()
|alert()
.id('node \'stream0\' in task \'{{ .TaskName }}\'')
.message('{{ .ID }} is {{ if eq .Level "OK" }}alive{{ else }}dead{{ end }}: {{ index .Fields "emitted" | printf "%0.3f" }} points/10s.')
.crit(lambda: "emitted" <= 100.0)
//Do normal processing of data
data...
```
The `id` and `message` alert properties can be configured globally via the 'deadman' configuration section.
Since the [AlertNode](/kapacitor/v1.4/nodes/alert_node/) is the last piece it can be further modified as usual.
Example:
```javascript
var data = stream
|from()...
// Trigger critical alert if the throughput drops below 100 points per 10s and checked every 10s.
data
|deadman(100.0, 10s)
.slack()
.channel('#dead_tasks')
//Do normal processing of data
data...
```
You can specify additional lambda expressions to further constrain when the deadman's switch is triggered.
Example:
```javascript
var data = stream
|from()...
// Trigger critical alert if the throughput drops below 100 points per 10s and checked every 10s.
// Only trigger the alert if the time of day is between 8am-5pm.
data
|deadman(100.0, 10s, lambda: hour("time") >= 8 AND hour("time") <= 17)
//Do normal processing of data
data...
```
```javascript
stateDuration|deadman(threshold float64, interval time.Duration, expr ...ast.LambdaNode)
```
Returns: [AlertNode](/kapacitor/v1.4/nodes/alert_node/)
<a class="top" href="javascript:document.getElementsByClassName('article-heading')[0].scrollIntoView();" title="top"><span class="icon arrow-up"></span></a>
### Default
Create a node that can set defaults for missing tags or fields.
```javascript
stateDuration|default()
```
Returns: [DefaultNode](/kapacitor/v1.4/nodes/default_node/)
<a class="top" href="javascript:document.getElementsByClassName('article-heading')[0].scrollIntoView();" title="top"><span class="icon arrow-up"></span></a>
### Delete
Create a node that can delete tags or fields.
```javascript
stateDuration|delete()
```
Returns: [DeleteNode](/kapacitor/v1.4/nodes/delete_node/)
<a class="top" href="javascript:document.getElementsByClassName('article-heading')[0].scrollIntoView();" title="top"><span class="icon arrow-up"></span></a>
### Derivative
Create a new node that computes the derivative of adjacent points.
```javascript
stateDuration|derivative(field string)
```
Returns: [DerivativeNode](/kapacitor/v1.4/nodes/derivative_node/)
<a class="top" href="javascript:document.getElementsByClassName('article-heading')[0].scrollIntoView();" title="top"><span class="icon arrow-up"></span></a>
### Difference
Compute the difference between points independent of elapsed time.
```javascript
stateDuration|difference(field string)
```
Returns: [InfluxQLNode](/kapacitor/v1.4/nodes/influx_q_l_node/)
<a class="top" href="javascript:document.getElementsByClassName('article-heading')[0].scrollIntoView();" title="top"><span class="icon arrow-up"></span></a>
### Distinct
Produce batch of only the distinct points.
```javascript
stateDuration|distinct(field string)
```
Returns: [InfluxQLNode](/kapacitor/v1.4/nodes/influx_q_l_node/)
<a class="top" href="javascript:document.getElementsByClassName('article-heading')[0].scrollIntoView();" title="top"><span class="icon arrow-up"></span></a>
### Ec2Autoscale
Create a node that can trigger autoscale events for a ec2 autoscalegroup.
```javascript
stateDuration|ec2Autoscale()
```
Returns: [Ec2AutoscaleNode](/kapacitor/v1.4/nodes/ec2_autoscale_node/)
<a class="top" href="javascript:document.getElementsByClassName('article-heading')[0].scrollIntoView();" title="top"><span class="icon arrow-up"></span></a>
### Elapsed
Compute the elapsed time between points
```javascript
stateDuration|elapsed(field string, unit time.Duration)
```
Returns: [InfluxQLNode](/kapacitor/v1.4/nodes/influx_q_l_node/)
<a class="top" href="javascript:document.getElementsByClassName('article-heading')[0].scrollIntoView();" title="top"><span class="icon arrow-up"></span></a>
### Eval
Create an eval node that will evaluate the given transformation function to each data point.
A list of expressions may be provided and will be evaluated in the order they are given.
The results are available to later expressions.
```javascript
stateDuration|eval(expressions ...ast.LambdaNode)
```
Returns: [EvalNode](/kapacitor/v1.4/nodes/eval_node/)
<a class="top" href="javascript:document.getElementsByClassName('article-heading')[0].scrollIntoView();" title="top"><span class="icon arrow-up"></span></a>
### First
Select the first point.
```javascript
stateDuration|first(field string)
```
Returns: [InfluxQLNode](/kapacitor/v1.4/nodes/influx_q_l_node/)
<a class="top" href="javascript:document.getElementsByClassName('article-heading')[0].scrollIntoView();" title="top"><span class="icon arrow-up"></span></a>
### Flatten
Flatten points with similar times into a single point.
```javascript
stateDuration|flatten()
```
Returns: [FlattenNode](/kapacitor/v1.4/nodes/flatten_node/)
<a class="top" href="javascript:document.getElementsByClassName('article-heading')[0].scrollIntoView();" title="top"><span class="icon arrow-up"></span></a>
### GroupBy
Group the data by a set of tags.
Can pass literal * to group by all dimensions.
Example:
```javascript
|groupBy(*)
```
```javascript
stateDuration|groupBy(tag ...interface{})
```
Returns: [GroupByNode](/kapacitor/v1.4/nodes/group_by_node/)
<a class="top" href="javascript:document.getElementsByClassName('article-heading')[0].scrollIntoView();" title="top"><span class="icon arrow-up"></span></a>
### HoltWinters
updated all latest links with latest shortcode, refactored related partial
2020-08-19 22:43:31 +00:00
Compute the holt-winters (/{{< latest "influxdb" "v1" >}}/query_language/functions/#holt-winters) forecast of a data set.
ported kapacitor 1.4
2020-07-30 16:38:32 +00:00
```javascript
stateDuration|holtWinters(field string, h int64, m int64, interval time.Duration)
```
Returns: [InfluxQLNode](/kapacitor/v1.4/nodes/influx_q_l_node/)
<a class="top" href="javascript:document.getElementsByClassName('article-heading')[0].scrollIntoView();" title="top"><span class="icon arrow-up"></span></a>
### HoltWintersWithFit
updated all latest links with latest shortcode, refactored related partial
2020-08-19 22:43:31 +00:00
Compute the holt-winters (/{{< latest "influxdb" "v1" >}}/query_language/functions/#holt-winters) forecast of a data set.
ported kapacitor 1.4
2020-07-30 16:38:32 +00:00
This method also outputs all the points used to fit the data in addition to the forecasted data.
```javascript
stateDuration|holtWintersWithFit(field string, h int64, m int64, interval time.Duration)
```
Returns: [InfluxQLNode](/kapacitor/v1.4/nodes/influx_q_l_node/)
<a class="top" href="javascript:document.getElementsByClassName('article-heading')[0].scrollIntoView();" title="top"><span class="icon arrow-up"></span></a>
### HttpOut
Create an HTTP output node that caches the most recent data it has received.
The cached data is available at the given endpoint.
The endpoint is the relative path from the API endpoint of the running task.
For example, if the task endpoint is at `/kapacitor/v1/tasks/<task_id>` and endpoint is
`top10`, then the data can be requested from `/kapacitor/v1/tasks/<task_id>/top10`.
```javascript
stateDuration|httpOut(endpoint string)
```
Returns: [HTTPOutNode](/kapacitor/v1.4/nodes/http_out_node/)
<a class="top" href="javascript:document.getElementsByClassName('article-heading')[0].scrollIntoView();" title="top"><span class="icon arrow-up"></span></a>
### HttpPost
Creates an HTTP Post node that POSTS received data to the provided HTTP endpoint.
HttpPost expects 0 or 1 arguments. If 0 arguments are provided, you must specify an
endpoint property method.
```javascript
stateDuration|httpPost(url ...string)
```
Returns: [HTTPPostNode](/kapacitor/v1.4/nodes/http_post_node/)
<a class="top" href="javascript:document.getElementsByClassName('article-heading')[0].scrollIntoView();" title="top"><span class="icon arrow-up"></span></a>
### InfluxDBOut
Create an influxdb output node that will store the incoming data into InfluxDB.
```javascript
stateDuration|influxDBOut()
```
Returns: [InfluxDBOutNode](/kapacitor/v1.4/nodes/influx_d_b_out_node/)
<a class="top" href="javascript:document.getElementsByClassName('article-heading')[0].scrollIntoView();" title="top"><span class="icon arrow-up"></span></a>
### Join
Join this node with other nodes. The data is joined on timestamp.
```javascript
stateDuration|join(others ...Node)
```
Returns: [JoinNode](/kapacitor/v1.4/nodes/join_node/)
<a class="top" href="javascript:document.getElementsByClassName('article-heading')[0].scrollIntoView();" title="top"><span class="icon arrow-up"></span></a>
### K8sAutoscale
Create a node that can trigger autoscale events for a kubernetes cluster.
```javascript
stateDuration|k8sAutoscale()
```
Returns: [K8sAutoscaleNode](/kapacitor/v1.4/nodes/k8s_autoscale_node/)
<a class="top" href="javascript:document.getElementsByClassName('article-heading')[0].scrollIntoView();" title="top"><span class="icon arrow-up"></span></a>
### KapacitorLoopback
Create an kapacitor loopback node that will send data back into Kapacitor as a stream.
```javascript
stateDuration|kapacitorLoopback()
```
Returns: [KapacitorLoopbackNode](/kapacitor/v1.4/nodes/kapacitor_loopback_node/)
<a class="top" href="javascript:document.getElementsByClassName('article-heading')[0].scrollIntoView();" title="top"><span class="icon arrow-up"></span></a>
### Last
Select the last point.
```javascript
stateDuration|last(field string)
```
Returns: [InfluxQLNode](/kapacitor/v1.4/nodes/influx_q_l_node/)
<a class="top" href="javascript:document.getElementsByClassName('article-heading')[0].scrollIntoView();" title="top"><span class="icon arrow-up"></span></a>
### Log
Create a node that logs all data it receives.
```javascript
stateDuration|log()
```
Returns: [LogNode](/kapacitor/v1.4/nodes/log_node/)
<a class="top" href="javascript:document.getElementsByClassName('article-heading')[0].scrollIntoView();" title="top"><span class="icon arrow-up"></span></a>
### Max
Select the maximum point.
```javascript
stateDuration|max(field string)
```
Returns: [InfluxQLNode](/kapacitor/v1.4/nodes/influx_q_l_node/)
<a class="top" href="javascript:document.getElementsByClassName('article-heading')[0].scrollIntoView();" title="top"><span class="icon arrow-up"></span></a>
### Mean
Compute the mean of the data.
```javascript
stateDuration|mean(field string)
```
Returns: [InfluxQLNode](/kapacitor/v1.4/nodes/influx_q_l_node/)
<a class="top" href="javascript:document.getElementsByClassName('article-heading')[0].scrollIntoView();" title="top"><span class="icon arrow-up"></span></a>
### Median
Compute the median of the data. Note, this method is not a selector,
if you want the median point use `.percentile(field, 50.0)`.
```javascript
stateDuration|median(field string)
```
Returns: [InfluxQLNode](/kapacitor/v1.4/nodes/influx_q_l_node/)
<a class="top" href="javascript:document.getElementsByClassName('article-heading')[0].scrollIntoView();" title="top"><span class="icon arrow-up"></span></a>
### Min
Select the minimum point.
```javascript
stateDuration|min(field string)
```
Returns: [InfluxQLNode](/kapacitor/v1.4/nodes/influx_q_l_node/)
<a class="top" href="javascript:document.getElementsByClassName('article-heading')[0].scrollIntoView();" title="top"><span class="icon arrow-up"></span></a>
### Mode
Compute the mode of the data.
```javascript
stateDuration|mode(field string)
```
Returns: [InfluxQLNode](/kapacitor/v1.4/nodes/influx_q_l_node/)
<a class="top" href="javascript:document.getElementsByClassName('article-heading')[0].scrollIntoView();" title="top"><span class="icon arrow-up"></span></a>
### MovingAverage
Compute a moving average of the last window points.
No points are emitted until the window is full.
```javascript
stateDuration|movingAverage(field string, window int64)
```
Returns: [InfluxQLNode](/kapacitor/v1.4/nodes/influx_q_l_node/)
<a class="top" href="javascript:document.getElementsByClassName('article-heading')[0].scrollIntoView();" title="top"><span class="icon arrow-up"></span></a>
### Percentile
Select a point at the given percentile. This is a selector function, no interpolation between points is performed.
```javascript
stateDuration|percentile(field string, percentile float64)
```
Returns: [InfluxQLNode](/kapacitor/v1.4/nodes/influx_q_l_node/)
<a class="top" href="javascript:document.getElementsByClassName('article-heading')[0].scrollIntoView();" title="top"><span class="icon arrow-up"></span></a>
### Sample
Create a new node that samples the incoming points or batches.
One point will be emitted every count or duration specified.
```javascript
stateDuration|sample(rate interface{})
```
Returns: [SampleNode](/kapacitor/v1.4/nodes/sample_node/)
<a class="top" href="javascript:document.getElementsByClassName('article-heading')[0].scrollIntoView();" title="top"><span class="icon arrow-up"></span></a>
### Shift
Create a new node that shifts the incoming points or batches in time.
```javascript
stateDuration|shift(shift time.Duration)
```
Returns: [ShiftNode](/kapacitor/v1.4/nodes/shift_node/)
<a class="top" href="javascript:document.getElementsByClassName('article-heading')[0].scrollIntoView();" title="top"><span class="icon arrow-up"></span></a>
### Sideload
Create a node that can load data from external sources
```javascript
stateDuration|sideload()
```
Returns: [SideloadNode](/kapacitor/v1.4/nodes/sideload_node/)
<a class="top" href="javascript:document.getElementsByClassName('article-heading')[0].scrollIntoView();" title="top"><span class="icon arrow-up"></span></a>
### Spread
Compute the difference between `min` and `max` points.
```javascript
stateDuration|spread(field string)
```
Returns: [InfluxQLNode](/kapacitor/v1.4/nodes/influx_q_l_node/)
<a class="top" href="javascript:document.getElementsByClassName('article-heading')[0].scrollIntoView();" title="top"><span class="icon arrow-up"></span></a>
### StateCount
Create a node that tracks number of consecutive points in a given state.
```javascript
stateDuration|stateCount(expression ast.LambdaNode)
```
Returns: [StateCountNode](/kapacitor/v1.4/nodes/state_count_node/)
<a class="top" href="javascript:document.getElementsByClassName('article-heading')[0].scrollIntoView();" title="top"><span class="icon arrow-up"></span></a>
### StateDuration
Create a node that tracks duration in a given state.
```javascript
stateDuration|stateDuration(expression ast.LambdaNode)
```
Returns: [StateDurationNode](/kapacitor/v1.4/nodes/state_duration_node/)
<a class="top" href="javascript:document.getElementsByClassName('article-heading')[0].scrollIntoView();" title="top"><span class="icon arrow-up"></span></a>
### Stats
Create a new stream of data that contains the internal statistics of the node.
The interval represents how often to emit the statistics based on real time.
This means the interval time is independent of the times of the data points the source node is receiving.
```javascript
stateDuration|stats(interval time.Duration)
```
Returns: [StatsNode](/kapacitor/v1.4/nodes/stats_node/)
<a class="top" href="javascript:document.getElementsByClassName('article-heading')[0].scrollIntoView();" title="top"><span class="icon arrow-up"></span></a>
### Stddev
Compute the standard deviation.
```javascript
stateDuration|stddev(field string)
```
Returns: [InfluxQLNode](/kapacitor/v1.4/nodes/influx_q_l_node/)
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### Sum
Compute the sum of all values.
```javascript
stateDuration|sum(field string)
```
Returns: [InfluxQLNode](/kapacitor/v1.4/nodes/influx_q_l_node/)
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### SwarmAutoscale
Create a node that can trigger autoscale events for a docker swarm cluster.
```javascript
stateDuration|swarmAutoscale()
```
Returns: [SwarmAutoscaleNode](/kapacitor/v1.4/nodes/swarm_autoscale_node/)
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### Top
Select the top `num` points for `field` and sort by any extra tags or fields.
```javascript
stateDuration|top(num int64, field string, fieldsAndTags ...string)
```
Returns: [InfluxQLNode](/kapacitor/v1.4/nodes/influx_q_l_node/)
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### Union
Perform the union of this node and all other given nodes.
```javascript
stateDuration|union(node ...Node)
```
Returns: [UnionNode](/kapacitor/v1.4/nodes/union_node/)
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### Where
Create a new node that filters the data stream by a given expression.
```javascript
stateDuration|where(expression ast.LambdaNode)
```
Returns: [WhereNode](/kapacitor/v1.4/nodes/where_node/)
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### Window
Create a new node that windows the stream by time.
NOTE: Window can only be applied to stream edges.
```javascript
stateDuration|window()
```
Returns: [WindowNode](/kapacitor/v1.4/nodes/window_node/)
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