AWS::EMR::Cluster CloudWatchAlarmDefinition

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.

Syntax

To declare this entity in your AWS CloudFormation template, use the following syntax:

JSON

{
  "ComparisonOperator" : String,
  "Dimensions" : [ MetricDimension, ... ],
  "EvaluationPeriods" : Integer,
  "MetricName" : String,
  "Namespace" : String,
  "Period" : Integer,
  "Statistic" : String,
  "Threshold" : Number,
  "Unit" : String
}

YAML

  ComparisonOperator: String
  Dimensions: 
    - MetricDimension
  EvaluationPeriods: Integer
  MetricName: String
  Namespace: String
  Period: Integer
  Statistic: String
  Threshold: Number
  Unit: String

Properties

ComparisonOperator

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

Required: Yes

Type: String

Allowed values: GREATER_THAN_OR_EQUAL | GREATER_THAN | LESS_THAN | LESS_THAN_OR_EQUAL

Update requires: No interruption

Dimensions

A CloudWatch metric dimension.

Required: No

Type: Array of MetricDimension

Update requires: No interruption

EvaluationPeriods

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.

Required: No

Type: Integer

Update requires: No interruption

MetricName

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

Required: Yes

Type: String

Update requires: No interruption

Namespace

The namespace for the CloudWatch metric. The default is AWS/ElasticMapReduce.

Required: No

Type: String

Update requires: No interruption

Period

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.

Required: Yes

Type: Integer

Update requires: No interruption

Statistic

The statistic to apply to the metric associated with the alarm. The default is AVERAGE.

Required: No

Type: String

Allowed values: SAMPLE_COUNT | AVERAGE | SUM | MINIMUM | MAXIMUM

Update requires: No interruption

Threshold

The value against which the specified statistic is compared.

Required: Yes

Type: Number

Update requires: No interruption

Unit

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.

Required: No

Type: String

Allowed values: NONE | SECONDS | MICRO_SECONDS | MILLI_SECONDS | BYTES | KILO_BYTES | MEGA_BYTES | GIGA_BYTES | TERA_BYTES | BITS | KILO_BITS | MEGA_BITS | GIGA_BITS | TERA_BITS | PERCENT | COUNT | BYTES_PER_SECOND | KILO_BYTES_PER_SECOND | MEGA_BYTES_PER_SECOND | GIGA_BYTES_PER_SECOND | TERA_BYTES_PER_SECOND | BITS_PER_SECOND | KILO_BITS_PER_SECOND | MEGA_BITS_PER_SECOND | GIGA_BITS_PER_SECOND | TERA_BITS_PER_SECOND | COUNT_PER_SECOND

Update requires: No interruption