--- title: EC2AutoscaleNode (Kapacitor TICKscript node) description: EC2AutoscaleNode triggers autoscale events on an AWS Autoscaling group. The node also outputs points for the triggered events. note: Auto generated by tickdoc menu: kapacitor_1_4: name: EC2AutoscaleNode identifier: ec2_autoscale_node weight: 80 parent: TICKscript nodes --- ### Constructor | Chaining Method | Description | |:---------|:---------| | **[ec2Autoscale](#descr) ( )** | Create a node that can trigger autoscale events for an EC2 Autoscale group. | ### Property Methods | Setters | Description | |:---|:---| | **[cluster](#cluster) ( `value` `string`)** | Cluster is the ID of EC2 Autoscale group to use. The ID of the cluster is specified in the kapacitor configuration. | | **[currentField](#currentfield) ( `value` `string`)** | CurrentField is the name of a field into which the current replica count will be set as an int. If empty no field will be set. Useful for computing deltas on the current state. | | **[decreaseCooldown](#decreasecooldown) ( `value` `time.Duration`)** | Only one decrease event can be triggered per resource every DecreaseCooldown interval. | | **[groupName](#groupname) ( `value` `string`)** | GroupName is the name of the autoscaling group to autoscale. | | **[groupNameTag](#groupnametag) ( `value` `string`)** | GroupName is the name of a tag which contains the name of the autoscaling group to autoscale. | | **[increaseCooldown](#increasecooldown) ( `value` `time.Duration`)** | Only one increase event can be triggered per resource every IncreaseCooldown interval. | | **[max](#max) ( `value` `int64`)** | The maximum scale factor to set. If 0 then there is no upper limit. Default: 0, a.k.a no limit. | | **[min](#min) ( `value` `int64`)** | The minimum scale factor to set. Default: 1 | | **[outputGroupNameTag](#outputgroupnametag) ( `value` `string`)** | OutputGroupName is the name of a tag into which the group name will be written for output autoscale events. Defaults to the value of GroupNameTag if its not empty. | | **[replicas](#replicas) ( `value` `ast.LambdaNode`)** | Replicas is a lambda expression that should evaluate to the desired number of replicas for the resource. | ### Chaining Methods [Alert](/kapacitor/v1.4/nodes/ec2_autoscale_node/#alert), [Barrier](/kapacitor/v1.4/nodes/ec2_autoscale_node/#barrier), [Bottom](/kapacitor/v1.4/nodes/ec2_autoscale_node/#bottom), [Combine](/kapacitor/v1.4/nodes/ec2_autoscale_node/#combine), [Count](/kapacitor/v1.4/nodes/ec2_autoscale_node/#count), [CumulativeSum](/kapacitor/v1.4/nodes/ec2_autoscale_node/#cumulativesum), [Deadman](/kapacitor/v1.4/nodes/ec2_autoscale_node/#deadman), [Default](/kapacitor/v1.4/nodes/ec2_autoscale_node/#default), [Delete](/kapacitor/v1.4/nodes/ec2_autoscale_node/#delete), [Derivative](/kapacitor/v1.4/nodes/ec2_autoscale_node/#derivative), [Difference](/kapacitor/v1.4/nodes/ec2_autoscale_node/#difference), [Distinct](/kapacitor/v1.4/nodes/ec2_autoscale_node/#distinct), [Ec2Autoscale](/kapacitor/v1.4/nodes/ec2_autoscale_node/#ec2autoscale), [Elapsed](/kapacitor/v1.4/nodes/ec2_autoscale_node/#elapsed), [Eval](/kapacitor/v1.4/nodes/ec2_autoscale_node/#eval), [First](/kapacitor/v1.4/nodes/ec2_autoscale_node/#first), [Flatten](/kapacitor/v1.4/nodes/ec2_autoscale_node/#flatten), [GroupBy](/kapacitor/v1.4/nodes/ec2_autoscale_node/#groupby), [HoltWinters](/kapacitor/v1.4/nodes/ec2_autoscale_node/#holtwinters), [HoltWintersWithFit](/kapacitor/v1.4/nodes/ec2_autoscale_node/#holtwinterswithfit), [HttpOut](/kapacitor/v1.4/nodes/ec2_autoscale_node/#httpout), [HttpPost](/kapacitor/v1.4/nodes/ec2_autoscale_node/#httppost), [InfluxDBOut](/kapacitor/v1.4/nodes/ec2_autoscale_node/#influxdbout), [Join](/kapacitor/v1.4/nodes/ec2_autoscale_node/#join), [K8sAutoscale](/kapacitor/v1.4/nodes/ec2_autoscale_node/#k8sautoscale), [KapacitorLoopback](/kapacitor/v1.4/nodes/ec2_autoscale_node/#kapacitorloopback), [Last](/kapacitor/v1.4/nodes/ec2_autoscale_node/#last), [Log](/kapacitor/v1.4/nodes/ec2_autoscale_node/#log), [Mean](/kapacitor/v1.4/nodes/ec2_autoscale_node/#mean), [Median](/kapacitor/v1.4/nodes/ec2_autoscale_node/#median), [Mode](/kapacitor/v1.4/nodes/ec2_autoscale_node/#mode), [MovingAverage](/kapacitor/v1.4/nodes/ec2_autoscale_node/#movingaverage), [Percentile](/kapacitor/v1.4/nodes/ec2_autoscale_node/#percentile), [Sample](/kapacitor/v1.4/nodes/ec2_autoscale_node/#sample), [Shift](/kapacitor/v1.4/nodes/ec2_autoscale_node/#shift), [Sideload](/kapacitor/v1.4/nodes/ec2_autoscale_node/#sideload), [Spread](/kapacitor/v1.4/nodes/ec2_autoscale_node/#spread), [StateCount](/kapacitor/v1.4/nodes/ec2_autoscale_node/#statecount), [StateDuration](/kapacitor/v1.4/nodes/ec2_autoscale_node/#stateduration), [Stats](/kapacitor/v1.4/nodes/ec2_autoscale_node/#stats), [Stddev](/kapacitor/v1.4/nodes/ec2_autoscale_node/#stddev), [Sum](/kapacitor/v1.4/nodes/ec2_autoscale_node/#sum), [SwarmAutoscale](/kapacitor/v1.4/nodes/ec2_autoscale_node/#swarmautoscale), [Top](/kapacitor/v1.4/nodes/ec2_autoscale_node/#top), [Union](/kapacitor/v1.4/nodes/ec2_autoscale_node/#union), [Where](/kapacitor/v1.4/nodes/ec2_autoscale_node/#where), [Window](/kapacitor/v1.4/nodes/ec2_autoscale_node/#window)

### Description EC2AutoscaleNode triggers autoscale events on an AWS Autoscaling group. The node also outputs points for the triggered events. Example: ```javascript // Target 80% cpu per ec2 instance var target = 80.0 var min = 1 var max = 10 var period = 5m var every = period stream |from() .measurement('cpu') .groupBy('host_name','group_name') .where(lambda: "cpu" == 'cpu-total') |eval(lambda: 100.0 - "usage_idle") .as('usage_percent') |window() .period(period) .every(every) |mean('usage_percent') .as('mean_cpu') |groupBy('group_name') |sum('mean_cpu') .as('total_cpu') |ec2Autoscale() // Get the group name of the VM(EC2 instance) from "group_name" tag. .groupNameTag('group_name') .min(min) .max(max) // Set the desired number of replicas based on target. .replicas(lambda: int(ceil("total_cpu" / target))) |influxDBOut() .database('deployments') .measurement('scale_events') .precision('s') ``` The above example computes the mean of CPU `usage_percent` by `host_name name` and `group_name`. Then sum of mean `cpu_usage` is calculated as `total_cpu`. Using the `total_cpu` over the last time period, a desired number of replicas is computed based on the target percentage usage of CPU. If the desired number of replicas has changed, Kapacitor makes the appropriate API call to AWS autoscaling group to update the replicas spec. Any time the Ec2Autoscale node changes a replica count, it emits a point. The point is tagged with the group name, using the `groupName` respectively In addition the group by tags will be preserved on the emitted point. The point contains two fields: `old`, and `new` representing change in the replicas. Available Statistics: * `increase_events`: number of times the replica count was increased. * `decrease_events`: number of times the replica count was decreased. * `cooldown_drops`: number of times an event was dropped because of a cooldown timer. * `errors`: number of errors encountered, typically related to communicating with the AWS autoscaling API. 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. ### `cluster` Cluster is the ID of the EC2 autoscale group to use. The ID of the cluster is specified in the Capacitor configuration. ```javascript ec2Autoscale.cluster(value string) ``` ### `currentField` CurrentField is the name of a field into which the current replica count will be set as an int. If empty no field will be set. Useful for computing deltas on the current state. Example: ```javascript |ec2Autoscale() .currentField('replicas') // Increase the replicas by 1 if the qps is over the threshold .replicas(lambda: if("qps" > threshold, "replicas" + 1, "replicas")) ``` ```javascript ec2Autoscale.currentField(value string) ``` ### `decreaseCooldown` Only one decrease event can be triggered per resource every DecreaseCooldown interval. ```javascript ec2Autoscale.decreaseCooldown(value time.Duration) ``` ### `groupName` GroupName is the name of the autoscaling group to autoscale. ```javascript ec2Autoscale.groupName(value string) ``` ### `groupNameTag` GroupName is the name of a tag which contains the name of the autoscaling group to autoscale. ```javascript ec2Autoscale.groupNameTag(value string) ``` ### `increaseCooldown` Only one increase event can be triggered per resource every IncreaseCooldown interval. ```javascript ec2Autoscale.increaseCooldown(value time.Duration) ``` ### `max` The maximum scale factor to set. If 0 then there is no upper limit. Default: 0, a.k.a no limit. ```javascript ec2Autoscale.max(value int64) ``` ### `min` The minimum scale factor to set. Default: 1 ```javascript ec2Autoscale.min(value int64) ``` ### `outputGroupNameTag` OutputGroupName is the name of a tag into which the group name will be written for output autoscale events. Defaults to the value of GroupNameTag if its not empty. ```javascript ec2Autoscale.outputGroupNameTag(value string) ``` ### `replicas` Replicas is a lambda expression that should evaluate to the desired number of replicas for the resource. ```javascript ec2Autoscale.replicas(value ast.LambdaNode) ``` 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 ec2Autoscale|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 ec2Autoscale|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 ec2Autoscale|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 ec2Autoscale|combine(expressions ...ast.LambdaNode) ``` Returns: [CombineNode](/kapacitor/v1.4/nodes/combine_node/) ### `count` Count the number of points. ```javascript ec2Autoscale|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 ec2Autoscale|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 ec2Autoscale|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 ec2Autoscale|default() ``` Returns: [DefaultNode](/kapacitor/v1.4/nodes/default_node/) ### `delete` Create a node that can delete tags or fields. ```javascript ec2Autoscale|delete() ``` Returns: [DeleteNode](/kapacitor/v1.4/nodes/delete_node/) ### `derivative` Create a new node that computes the derivative of adjacent points. ```javascript ec2Autoscale|derivative(field string) ``` Returns: [DerivativeNode](/kapacitor/v1.4/nodes/derivative_node/) ### `difference` Compute the difference between points independent of elapsed time. ```javascript ec2Autoscale|difference(field string) ``` Returns: [InfluxQLNode](/kapacitor/v1.4/nodes/influx_q_l_node/) ### `distinct` Produce batch of only the distinct points. ```javascript ec2Autoscale|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 ec2Autoscale|ec2Autoscale() ``` Returns: [Ec2AutoscaleNode](/kapacitor/v1.4/nodes/ec2_autoscale_node/) ### `elapsed` Compute the elapsed time between points. ```javascript ec2Autoscale|elapsed(field string, unit time.Duration) ``` Returns: [InfluxQLNode](/kapacitor/v1.4/nodes/influx_q_l_node/) ### `eval` Create a 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 ec2Autoscale|eval(expressions ...ast.LambdaNode) ``` Returns: [EvalNode](/kapacitor/v1.4/nodes/eval_node/) ### `first` Select the first point. ```javascript ec2Autoscale|first(field string) ``` Returns: [InfluxQLNode](/kapacitor/v1.4/nodes/influx_q_l_node/) ### `flatten` Flatten points with similar times into a single point. ```javascript ec2Autoscale|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 ec2Autoscale|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 ec2Autoscale|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 ec2Autoscale|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 ec2Autoscale|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 ec2Autoscale|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 ec2Autoscale|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 ec2Autoscale|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 ec2Autoscale|k8sAutoscale() ``` Returns: [K8sAutoscaleNode](/kapacitor/v1.4/nodes/k8s_autoscale_node/) ### `kapacitorLoopback` Create a Kapacitor loopback node that will send data back into Kapacitor as a stream. ```javascript ec2Autoscale|kapacitorLoopback() ``` Returns: [KapacitorLoopbackNode](/kapacitor/v1.4/nodes/kapacitor_loopback_node/) ### `last` Select the last point. ```javascript ec2Autoscale|last(field string) ``` Returns: [InfluxQLNode](/kapacitor/v1.4/nodes/influx_q_l_node/) ### `log` Create a node that logs all data it receives. ```javascript ec2Autoscale|log() ``` Returns: [LogNode](/kapacitor/v1.4/nodes/log_node/) ### `mean` Compute the mean of the data. ```javascript ec2Autoscale|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 ec2Autoscale|median(field string) ``` Returns: [InfluxQLNode](/kapacitor/v1.4/nodes/influx_q_l_node/) ### `mode` Compute the mode of the data. ```javascript ec2Autoscale|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 ec2Autoscale|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 ec2Autoscale|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 ec2Autoscale|sample(rate interface{}) ``` Returns: [SampleNode](/kapacitor/v1.4/nodes/sample_node/) ### `shift` Create a node that shifts the incoming points or batches in time. ```javascript ec2Autoscale|shift(shift time.Duration) ``` Returns: [ShiftNode](/kapacitor/v1.4/nodes/shift_node/) ### `sideload` Create a node that can load data from external sources ```javascript ec2Autoscale|sideload() ``` Returns: [SideloadNode](/kapacitor/v1.4/nodes/sideload_node/) ### `spread` Compute the difference between `min` and `max` points. ```javascript ec2Autoscale|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 ec2Autoscale|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 ec2Autoscale|stateDuration(expression ast.LambdaNode) ``` Returns: [StateDurationNode](/kapacitor/v1.4/nodes/state_duration_node/) ### `stats` Create a 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 ec2Autoscale|stats(interval time.Duration) ``` Returns: [StatsNode](/kapacitor/v1.4/nodes/stats_node/) ### `stddev` Compute the standard deviation. ```javascript ec2Autoscale|stddev(field string) ``` Returns: [InfluxQLNode](/kapacitor/v1.4/nodes/influx_q_l_node/) ### `sum` Compute the sum of all values. ```javascript ec2Autoscale|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 ec2Autoscale|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 ec2Autoscale|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 ec2Autoscale|union(node ...Node) ``` Returns: [UnionNode](/kapacitor/v1.4/nodes/union_node/) ### `where` Create a node that filters the data stream by a given expression. ```javascript ec2Autoscale|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 ec2Autoscale|window() ``` Returns: [WindowNode](/kapacitor/v1.4/nodes/window_node/)