interface CloudWatchAlarmDefinitionProperty

Language	Type name
.NET	`Amazon.CDK.AWS.EMR.CfnInstanceGroupConfig.CloudWatchAlarmDefinitionProperty`
Java	`software.amazon.awscdk.services.emr.CfnInstanceGroupConfig.CloudWatchAlarmDefinitionProperty`
Python	`aws_cdk.aws_emr.CfnInstanceGroupConfig.CloudWatchAlarmDefinitionProperty`
TypeScript	`@aws-cdk/aws-emr` » `CfnInstanceGroupConfig` » `CloudWatchAlarmDefinitionProperty`

CloudWatchAlarmDefinition is a subproperty of the ScalingTrigger property, which determines when to trigger an automatic scaling activity.

Scaling activity begins when you satisfy the defined alarm conditions.

Example

// The code below shows an example of how to instantiate this type.
// The values are placeholders you should change.
import * as emr from '@aws-cdk/aws-emr';
const cloudWatchAlarmDefinitionProperty: emr.CfnInstanceGroupConfig.CloudWatchAlarmDefinitionProperty = {
  comparisonOperator: 'comparisonOperator',
  metricName: 'metricName',
  period: 123,
  threshold: 123,

  // the properties below are optional
  dimensions: [{
    key: 'key',
    value: 'value',
  }],
  evaluationPeriods: 123,
  namespace: 'namespace',
  statistic: 'statistic',
  unit: 'unit',
};

Properties

Name	Type	Description
comparisonOperator	`string`	Determines how the metric specified by `MetricName` is compared to the value specified by `Threshold` .
metricName	`string`	The name of the CloudWatch metric that is watched to determine an alarm condition.
period	`number`	The period, in seconds, over which the statistic is applied.
threshold	`number`	The value against which the specified statistic is compared.
dimensions?	`IResolvable` `\|` `IResolvable` `\|` `MetricDimensionProperty[]`	A CloudWatch metric dimension.
evaluationPeriods?	`number`	The number of periods, in five-minute increments, during which the alarm condition must exist before the alarm triggers automatic scaling activity.
namespace?	`string`	The namespace for the CloudWatch metric.
statistic?	`string`	The statistic to apply to the metric associated with the alarm.
unit?	`string`	The unit of measure associated with the CloudWatch metric being watched.

comparisonOperator

Type: string

Determines how the metric specified by MetricName is compared to the value specified by Threshold .

metricName

Type: string

The name of the CloudWatch metric that is watched to determine an alarm condition.

period

Type: number

The period, in seconds, over which the statistic is applied.

CloudWatch metrics for Amazon EMR are emitted every five minutes (300 seconds), so if you specify a CloudWatch metric, specify 300 .

threshold

Type: number

The value against which the specified statistic is compared.

dimensions?

Type: IResolvable | IResolvable | MetricDimensionProperty[] (optional)

A CloudWatch metric dimension.

evaluationPeriods?

Type: number (optional)

The number of periods, in five-minute increments, during which the alarm condition must exist before the alarm triggers automatic scaling activity.

The default value is 1 .

namespace?

Type: string (optional)

The namespace for the CloudWatch metric.

The default is AWS/ElasticMapReduce .

statistic?

Type: string (optional)

The statistic to apply to the metric associated with the alarm.

The default is AVERAGE .

unit?

Type: string (optional)

The unit of measure associated with the CloudWatch metric being watched.

The value specified for Unit must correspond to the units specified in the CloudWatch metric.