CloudWatchAlarmDefinition

The definition of a CloudWatch metric alarm, which determines when an automatic scaling activity is triggered. When the defined alarm conditions are satisfied, scaling activity begins.

ComparisonOperator

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

Type: String

Valid Values: GREATER_THAN_OR_EQUAL | GREATER_THAN | LESS_THAN | LESS_THAN_OR_EQUAL

Required: Yes

Dimensions

A CloudWatch metric dimension.

Type: Array of MetricDimension objects

Required: No

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.

Type: Integer

Required: No

MetricName

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

Type: String

Required: Yes

Namespace

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

Type: String

Required: No

Period

The period, in seconds, over which the statistic is applied. EMR CloudWatch metrics are emitted every five minutes (300 seconds), so if an EMR CloudWatch metric is specified, specify 300.

Type: Integer

Required: Yes

Statistic

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

Type: String

Valid Values: SAMPLE_COUNT | AVERAGE | SUM | MINIMUM | MAXIMUM

Required: No

Threshold

The value against which the specified statistic is compared.

Type: Double

Valid Range: Minimum value of 0.0.

Required: Yes

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.

Type: String

Required: No

CloudWatchAlarmDefinition

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