This is the new Amazon CloudFormation Template Reference Guide. Please update your bookmarks and links. For help getting started with CloudFormation, see the Amazon CloudFormation User Guide.
AWS::CloudWatch::Alarm Dimension
Dimension is an embedded property of the AWS::CloudWatch::Alarm type. Dimensions 
           are name/value pairs that can be associated with a CloudWatch metric. You can 
           specify a maximum of 30 dimensions for a given metric.
Syntax
To declare this entity in your Amazon CloudFormation template, use the following syntax:
Properties
- Name
- 
                    The name of the dimension, from 1–255 characters in length. This dimension name must have been included when the metric was published. Required: Yes Type: String Minimum: 1Maximum: 255Update requires: No interruption 
- Value
- 
                    The value for the dimension, from 1–255 characters in length. Required: Yes Type: String Minimum: 1Maximum: 1024Update requires: No interruption 
Examples
Two alarms with dimension values supplied by the Ref function
The Ref and GetAtt intrinsic functions are often used to supply values for CloudWatch metric dimensions. Here is an example using the Ref function.
JSON
{ "CPUAlarmHigh": { "Type": "AWS::CloudWatch::Alarm", "Properties": { "AlarmDescription": "Scale-up if CPU is greater than 90% for 10 minutes", "MetricName": "CPUUtilization", "Namespace": "AWS/EC2", "Statistic": "Average", "Period": "300", "EvaluationPeriods": "2", "Threshold": "90", "AlarmActions": [ { "Ref": "WebServerScaleUpPolicy" } ], "Dimensions": [ { "Name": "AutoScalingGroupName", "Value": { "Ref": "WebServerGroup" } } ], "ComparisonOperator": "GreaterThanThreshold" } }, "CPUAlarmLow": { "Type": "AWS::CloudWatch::Alarm", "Properties": { "AlarmDescription": "Scale-down if CPU is less than 70% for 10 minutes", "MetricName": "CPUUtilization", "Namespace": "AWS/EC2", "Statistic": "Average", "Period": "300", "EvaluationPeriods": "2", "Threshold": "70", "AlarmActions": [ { "Ref": "WebServerScaleDownPolicy" } ], "Dimensions": [ { "Name": "AutoScalingGroupName", "Value": { "Ref": "WebServerGroup" } } ], "ComparisonOperator": "LessThanThreshold" } } }
YAML
CPUAlarmHigh: Type: 'AWS::CloudWatch::Alarm' Properties: AlarmDescription: Scale-up if CPU is greater than 90% for 10 minutes MetricName: CPUUtilization Namespace: AWS/EC2 Statistic: Average Period: '300' EvaluationPeriods: '2' Threshold: '90' AlarmActions: - !Ref WebServerScaleUpPolicy Dimensions: - Name: AutoScalingGroupName Value: !Ref WebServerGroup ComparisonOperator: GreaterThanThreshold CPUAlarmLow: Type: 'AWS::CloudWatch::Alarm' Properties: AlarmDescription: Scale-down if CPU is less than 70% for 10 minutes MetricName: CPUUtilization Namespace: AWS/EC2 Statistic: Average Period: '300' EvaluationPeriods: '2' Threshold: '70' AlarmActions: - !Ref WebServerScaleDownPolicy Dimensions: - Name: AutoScalingGroupName Value: !Ref WebServerGroup ComparisonOperator: LessThanThreshold