--- title: GroupByNode (Kapacitor TICKscript node) description: GroupByNode groups incoming data. Each group is then processed independently for the rest of the pipeline. Only tags that are dimensions in the grouping will be preserved; all other tags are dropped. note: Auto generated by tickdoc menu: kapacitor_1_4: name: GroupByNode identifier: group_by_node weight: 120 parent: TICKscript nodes --- ### Constructor | Chaining Method | Description | |:---------|:---------| | **[groupBy](#descr) ( `tag` `...interface{}`)** | Group the data by a set of tags. | ### Property Methods | Setters | Description | |:---|:---| | **[byMeasurement](#bymeasurement) ( )** | If set will include the measurement name in the group ID. Along with any other group by dimensions. | ### Chaining Methods [Alert](/kapacitor/v1.4/nodes/group_by_node/#alert), [Barrier](/kapacitor/v1.4/nodes/group_by_node/#barrier), [Bottom](/kapacitor/v1.4/nodes/group_by_node/#bottom), [Combine](/kapacitor/v1.4/nodes/group_by_node/#combine), [Count](/kapacitor/v1.4/nodes/group_by_node/#count), [CumulativeSum](/kapacitor/v1.4/nodes/group_by_node/#cumulativesum), [Deadman](/kapacitor/v1.4/nodes/group_by_node/#deadman), [Default](/kapacitor/v1.4/nodes/group_by_node/#default), [Delete](/kapacitor/v1.4/nodes/group_by_node/#delete), [Derivative](/kapacitor/v1.4/nodes/group_by_node/#derivative), [Difference](/kapacitor/v1.4/nodes/group_by_node/#difference), [Distinct](/kapacitor/v1.4/nodes/group_by_node/#distinct), [Ec2Autoscale](/kapacitor/v1.4/nodes/group_by_node/#ec2autoscale), [Elapsed](/kapacitor/v1.4/nodes/group_by_node/#elapsed), [Eval](/kapacitor/v1.4/nodes/group_by_node/#eval), [Exclude](/kapacitor/v1.4/nodes/group_by_node/#exclude), [First](/kapacitor/v1.4/nodes/group_by_node/#first), [Flatten](/kapacitor/v1.4/nodes/group_by_node/#flatten), [GroupBy](/kapacitor/v1.4/nodes/group_by_node/#groupby), [HoltWinters](/kapacitor/v1.4/nodes/group_by_node/#holtwinters), [HoltWintersWithFit](/kapacitor/v1.4/nodes/group_by_node/#holtwinterswithfit), [HttpOut](/kapacitor/v1.4/nodes/group_by_node/#httpout), [HttpPost](/kapacitor/v1.4/nodes/group_by_node/#httppost), [InfluxDBOut](/kapacitor/v1.4/nodes/group_by_node/#influxdbout), [Join](/kapacitor/v1.4/nodes/group_by_node/#join), [K8sAutoscale](/kapacitor/v1.4/nodes/group_by_node/#k8sautoscale), [KapacitorLoopback](/kapacitor/v1.4/nodes/group_by_node/#kapacitorloopback), [Last](/kapacitor/v1.4/nodes/group_by_node/#last), [Log](/kapacitor/v1.4/nodes/group_by_node/#log), [Max](/kapacitor/v1.4/nodes/group_by_node/#max), [Mean](/kapacitor/v1.4/nodes/group_by_node/#mean), [Median](/kapacitor/v1.4/nodes/group_by_node/#median), [Min](/kapacitor/v1.4/nodes/group_by_node/#min), [Mode](/kapacitor/v1.4/nodes/group_by_node/#mode), [MovingAverage](/kapacitor/v1.4/nodes/group_by_node/#movingaverage), [Percentile](/kapacitor/v1.4/nodes/group_by_node/#percentile), [Sample](/kapacitor/v1.4/nodes/group_by_node/#sample), [Shift](/kapacitor/v1.4/nodes/group_by_node/#shift), [Sideload](/kapacitor/v1.4/nodes/group_by_node/#sideload), [Spread](/kapacitor/v1.4/nodes/group_by_node/#spread), [StateCount](/kapacitor/v1.4/nodes/group_by_node/#statecount), [StateDuration](/kapacitor/v1.4/nodes/group_by_node/#stateduration), [Stats](/kapacitor/v1.4/nodes/group_by_node/#stats), [Stddev](/kapacitor/v1.4/nodes/group_by_node/#stddev), [Sum](/kapacitor/v1.4/nodes/group_by_node/#sum), [SwarmAutoscale](/kapacitor/v1.4/nodes/group_by_node/#swarmautoscale), [Top](/kapacitor/v1.4/nodes/group_by_node/#top), [Union](/kapacitor/v1.4/nodes/group_by_node/#union), [Where](/kapacitor/v1.4/nodes/group_by_node/#where), [Window](/kapacitor/v1.4/nodes/group_by_node/#window)

### Description A [GroupBy node](/kapacitor/v1.4/nodes/group_by_node/) will group the incoming data. Each group is then processed independently for the rest of the pipeline. Only tags that are dimensions in the grouping will be preserved; all other tags are dropped. Example: ```javascript stream |groupBy('service', 'datacenter') ... ``` The above example groups the data along two dimensions `service` and `datacenter`. Groups are dynamically created as new data arrives and each group is processed independently.
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. ### ByMeasurement If set will include the measurement name in the group ID. Along with any other group by dimensions. Example: ```javascript ... |groupBy('host') .byMeasurement() ``` The above example groups points by their host tag and measurement name. If you want to remove the measurement name from the group ID, then groupBy all existing dimensions but without specifying 'byMeasurement'. Example: ```javascript |groupBy(*) ``` The above removes the group by measurement name if any. ```javascript groupBy.byMeasurement() ``` 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 groupBy|alert() ``` Returns: [AlertNode](/kapacitor/v1.4/nodes/alert_node/) ### Barrier Create a new Barrier node that emits a BarrierMessage periodically One BarrierMessage will be emitted every period duration ```javascript groupBy|barrier() ``` Returns: [BarrierNode](/kapacitor/v1.4/nodes/barrier_node/) ### Bottom Select the bottom `num` points for `field` and sort by any extra tags or fields. ```javascript groupBy|bottom(num int64, field string, fieldsAndTags ...string) ``` Returns: [InfluxQLNode](/kapacitor/v1.4/nodes/influx_q_l_node/) ### Combine Combine this node with itself. The data is combined on timestamp. ```javascript groupBy|combine(expressions ...ast.LambdaNode) ``` Returns: [CombineNode](/kapacitor/v1.4/nodes/combine_node/) ### Count Count the number of points. ```javascript groupBy|count(field string) ``` Returns: [InfluxQLNode](/kapacitor/v1.4/nodes/influx_q_l_node/) ### CumulativeSum Compute a cumulative sum of each point that is received. A point is emitted for every point collected. ```javascript groupBy|cumulativeSum(field string) ``` Returns: [InfluxQLNode](/kapacitor/v1.4/nodes/influx_q_l_node/) ### 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 groupBy|deadman(threshold float64, interval time.Duration, expr ...ast.LambdaNode) ``` Returns: [AlertNode](/kapacitor/v1.4/nodes/alert_node/) ### Default Create a node that can set defaults for missing tags or fields. ```javascript groupBy|default() ``` Returns: [DefaultNode](/kapacitor/v1.4/nodes/default_node/) ### Delete Create a node that can delete tags or fields. ```javascript groupBy|delete() ``` Returns: [DeleteNode](/kapacitor/v1.4/nodes/delete_node/) ### Derivative Create a new node that computes the derivative of adjacent points. ```javascript groupBy|derivative(field string) ``` Returns: [DerivativeNode](/kapacitor/v1.4/nodes/derivative_node/) ### Difference Compute the difference between points independent of elapsed time. ```javascript groupBy|difference(field string) ``` Returns: [InfluxQLNode](/kapacitor/v1.4/nodes/influx_q_l_node/) ### Distinct Produce batch of only the distinct points. ```javascript groupBy|distinct(field string) ``` Returns: [InfluxQLNode](/kapacitor/v1.4/nodes/influx_q_l_node/) ### Ec2Autoscale Create a node that can trigger autoscale events for a ec2 autoscalegroup. ```javascript groupBy|ec2Autoscale() ``` Returns: [Ec2AutoscaleNode](/kapacitor/v1.4/nodes/ec2_autoscale_node/) ### Elapsed Compute the elapsed time between points ```javascript groupBy|elapsed(field string, unit time.Duration) ``` Returns: [InfluxQLNode](/kapacitor/v1.4/nodes/influx_q_l_node/) ### 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 groupBy|eval(expressions ...ast.LambdaNode) ``` Returns: [EvalNode](/kapacitor/v1.4/nodes/eval_node/) ### Exclude Exclude removes any tags from the group. ```javascript groupBy|exclude(dims ...string) ``` Returns: [GroupByNode](/kapacitor/v1.4/nodes/group_by_node/) ### First Select the first point. ```javascript groupBy|first(field string) ``` Returns: [InfluxQLNode](/kapacitor/v1.4/nodes/influx_q_l_node/) ### Flatten Flatten points with similar times into a single point. ```javascript groupBy|flatten() ``` Returns: [FlattenNode](/kapacitor/v1.4/nodes/flatten_node/) ### GroupBy Group the data by a set of tags. Can pass literal * to group by all dimensions. Example: ```javascript |groupBy(*) ``` ```javascript groupBy|groupBy(tag ...interface{}) ``` Returns: [GroupByNode](/kapacitor/v1.4/nodes/group_by_node/) ### HoltWinters Compute the holt-winters (/{{< latest "influxdb" "v1" >}}/query_language/functions/#holt-winters) forecast of a data set. ```javascript groupBy|holtWinters(field string, h int64, m int64, interval time.Duration) ``` Returns: [InfluxQLNode](/kapacitor/v1.4/nodes/influx_q_l_node/) ### HoltWintersWithFit Compute the holt-winters (/{{< latest "influxdb" "v1" >}}/query_language/functions/#holt-winters) forecast of a data set. This method also outputs all the points used to fit the data in addition to the forecasted data. ```javascript groupBy|holtWintersWithFit(field string, h int64, m int64, interval time.Duration) ``` Returns: [InfluxQLNode](/kapacitor/v1.4/nodes/influx_q_l_node/) ### 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/` and endpoint is `top10`, then the data can be requested from `/kapacitor/v1/tasks//top10`. ```javascript groupBy|httpOut(endpoint string) ``` Returns: [HTTPOutNode](/kapacitor/v1.4/nodes/http_out_node/) ### 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 groupBy|httpPost(url ...string) ``` Returns: [HTTPPostNode](/kapacitor/v1.4/nodes/http_post_node/) ### InfluxDBOut Create an influxdb output node that will store the incoming data into InfluxDB. ```javascript groupBy|influxDBOut() ``` Returns: [InfluxDBOutNode](/kapacitor/v1.4/nodes/influx_d_b_out_node/) ### Join Join this node with other nodes. The data is joined on timestamp. ```javascript groupBy|join(others ...Node) ``` Returns: [JoinNode](/kapacitor/v1.4/nodes/join_node/) ### K8sAutoscale Create a node that can trigger autoscale events for a kubernetes cluster. ```javascript groupBy|k8sAutoscale() ``` Returns: [K8sAutoscaleNode](/kapacitor/v1.4/nodes/k8s_autoscale_node/) ### KapacitorLoopback Create an kapacitor loopback node that will send data back into Kapacitor as a stream. ```javascript groupBy|kapacitorLoopback() ``` Returns: [KapacitorLoopbackNode](/kapacitor/v1.4/nodes/kapacitor_loopback_node/) ### Last Select the last point. ```javascript groupBy|last(field string) ``` Returns: [InfluxQLNode](/kapacitor/v1.4/nodes/influx_q_l_node/) ### Log Create a node that logs all data it receives. ```javascript groupBy|log() ``` Returns: [LogNode](/kapacitor/v1.4/nodes/log_node/) ### Max Select the maximum point. ```javascript groupBy|max(field string) ``` Returns: [InfluxQLNode](/kapacitor/v1.4/nodes/influx_q_l_node/) ### Mean Compute the mean of the data. ```javascript groupBy|mean(field string) ``` Returns: [InfluxQLNode](/kapacitor/v1.4/nodes/influx_q_l_node/) ### 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 groupBy|median(field string) ``` Returns: [InfluxQLNode](/kapacitor/v1.4/nodes/influx_q_l_node/) ### Min Select the minimum point. ```javascript groupBy|min(field string) ``` Returns: [InfluxQLNode](/kapacitor/v1.4/nodes/influx_q_l_node/) ### Mode Compute the mode of the data. ```javascript groupBy|mode(field string) ``` Returns: [InfluxQLNode](/kapacitor/v1.4/nodes/influx_q_l_node/) ### MovingAverage Compute a moving average of the last window points. No points are emitted until the window is full. ```javascript groupBy|movingAverage(field string, window int64) ``` Returns: [InfluxQLNode](/kapacitor/v1.4/nodes/influx_q_l_node/) ### Percentile Select a point at the given percentile. This is a selector function, no interpolation between points is performed. ```javascript groupBy|percentile(field string, percentile float64) ``` Returns: [InfluxQLNode](/kapacitor/v1.4/nodes/influx_q_l_node/) ### Sample Create a new node that samples the incoming points or batches. One point will be emitted every count or duration specified. ```javascript groupBy|sample(rate interface{}) ``` Returns: [SampleNode](/kapacitor/v1.4/nodes/sample_node/) ### Shift Create a new node that shifts the incoming points or batches in time. ```javascript groupBy|shift(shift time.Duration) ``` Returns: [ShiftNode](/kapacitor/v1.4/nodes/shift_node/) ### Sideload Create a node that can load data from external sources ```javascript groupBy|sideload() ``` Returns: [SideloadNode](/kapacitor/v1.4/nodes/sideload_node/) ### Spread Compute the difference between `min` and `max` points. ```javascript groupBy|spread(field string) ``` Returns: [InfluxQLNode](/kapacitor/v1.4/nodes/influx_q_l_node/) ### StateCount Create a node that tracks number of consecutive points in a given state. ```javascript groupBy|stateCount(expression ast.LambdaNode) ``` Returns: [StateCountNode](/kapacitor/v1.4/nodes/state_count_node/) ### StateDuration Create a node that tracks duration in a given state. ```javascript groupBy|stateDuration(expression ast.LambdaNode) ``` Returns: [StateDurationNode](/kapacitor/v1.4/nodes/state_duration_node/) ### 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 groupBy|stats(interval time.Duration) ``` Returns: [StatsNode](/kapacitor/v1.4/nodes/stats_node/) ### Stddev Compute the standard deviation. ```javascript groupBy|stddev(field string) ``` Returns: [InfluxQLNode](/kapacitor/v1.4/nodes/influx_q_l_node/) ### Sum Compute the sum of all values. ```javascript groupBy|sum(field string) ``` Returns: [InfluxQLNode](/kapacitor/v1.4/nodes/influx_q_l_node/) ### SwarmAutoscale Create a node that can trigger autoscale events for a docker swarm cluster. ```javascript groupBy|swarmAutoscale() ``` Returns: [SwarmAutoscaleNode](/kapacitor/v1.4/nodes/swarm_autoscale_node/) ### Top Select the top `num` points for `field` and sort by any extra tags or fields. ```javascript groupBy|top(num int64, field string, fieldsAndTags ...string) ``` Returns: [InfluxQLNode](/kapacitor/v1.4/nodes/influx_q_l_node/) ### Union Perform the union of this node and all other given nodes. ```javascript groupBy|union(node ...Node) ``` Returns: [UnionNode](/kapacitor/v1.4/nodes/union_node/) ### Where Create a new node that filters the data stream by a given expression. ```javascript groupBy|where(expression ast.LambdaNode) ``` Returns: [WhereNode](/kapacitor/v1.4/nodes/where_node/) ### Window Create a new node that windows the stream by time. NOTE: Window can only be applied to stream edges. ```javascript groupBy|window() ``` Returns: [WindowNode](/kapacitor/v1.4/nodes/window_node/)