AWS CloudFormation中的AWS::CloudWatch::Alarm资源类型可以用来创建CloudWatch警报。当多个维度被添加到一个警报中时，此资源类型可能无法正常工作。为了解决这个问题，可以使用AWS::CloudWatch::CompositeAlarm资源类型，它可以通过一个或多个指标，一个布尔逻辑表达式和/或多个警报来创建一个组合警报。以下是一个使用AWS::CloudWatch::CompositeAlarm来创建组合警报的简单示例：

Resources:
  MyCompositeAlarm:
    Type: AWS::CloudWatch::CompositeAlarm
    Properties:
      ActionsEnabled: true
      AlarmActions: [ arn:aws:sns:us-east-1:111111111111:MySNSTopic ]
      AlarmDescription: Description of my composite alarm
      AlarmName: MyCompositeAlarm
      AlarmRule: AND [
        { "Ref" : "MyFirstMetricAlarm" },
        { "Ref" : "MySecondMetricAlarm" }
      ]
      OKActions: [ arn:aws:sns:us-east-1:111111111111:MySNSTopic ]
      InsufficientDataActions: [ arn:aws:sns:us-east-1:111111111111:MySNSTopic ]
      
  MyFirstMetricAlarm:
    Type: AWS::CloudWatch::Alarm
    Properties:
      AlarmDescription: Description of my first metric alarm
      AlarmName: MyFirstMetricAlarm
      ComparisonOperator: GreaterThanThreshold
      EvaluationPeriods: '1'
      MetricName: MyMetric
      Namespace: AWS/EC2
      Period: '60'
      Statistic: Average
      Threshold: '100'
      Dimensions:
        - Name: InstanceId
          Value: { "Ref" : "MyInstanceId" }
          
  MySecondMetricAlarm:
    Type: AWS::CloudWatch::Alarm
    Properties:
      AlarmDescription: Description of my second metric alarm
      AlarmName: MySecondMetricAlarm
      ComparisonOperator: LessThanThreshold
      EvaluationPeriods: '1'
      MetricName: