Amazon cloudformation 如何使用CloudFormation在两个指标的总和上定义CloudWatch警报？

当两个不同队列上的相同度量值EnumberOfMessagesVisible的总和超过100时，我需要触发警报

2017年9月，answer表示，唯一的方法是使用Lambda函数获取两个值，并通过CloudWatch API将它们相加

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在编写时，2月19日，它是可以使用的，因此不需要lambda函数或EC2实例。是否可以使用度量数学直接在CloudFormation中定义报警？

实际上可以直接在CloudFormation中实现报警逻辑

假设有两个缩放策略ECSSCALEAUP和ECSSCALEADOWN，报警定义如下所示：

ECSWorkerSQSCumulativeAlarm:
  Type: AWS::CloudWatch::Alarm
  Properties:
    AlarmName: !Join ['-', [!Ref 'MyService', 'SQSCumulativeAlarm']]
    AlarmDescription: "Trigger ECS Service Scaling based on TWO SQS queues"
    Metrics:
      - Id: e1
        Expression: "fq + sq"
        Label: "Sum of the two Metrics"
      - Id: fq
        MetricStat:
          Metric:
            MetricName: ApproximateNumberOfMessagesVisible
            Namespace: AWS/SQS
            Dimensions:
              - Name: QueueName
                Value: !GetAtt [ FirstQueue, QueueName]
        Period: 60
        Stat: Average
        Unit: Count
        ReturnData: false
      - Id: sq
        MetricStat:
          Metric:
            MetricName: ApproximateNumberOfMessagesVisible
            Namespace: AWS/SQS
            Dimensions:
              - Name: QueueName
                Value: !GetAtt [ SecondQueue, QueueName]
          Period: 60
          Stat: Average
          Unit: Count
        ReturnData: false
    EvaluationPeriods: 2
    Threshold: 100
    ComparisonOperator: GreaterThanThreshold
    AlarmActions:
      - !Ref ECSScaleUp
      - !Ref ECSScaleDown
    OKActions:
      - !Ref ECSScaleUp
      - !Ref ECSScaleDown

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实际上，可以直接在云信息中实现报警逻辑

假设有两个缩放策略ECSSCALEAUP和ECSSCALEADOWN，报警定义如下所示：

ECSWorkerSQSCumulativeAlarm:
  Type: AWS::CloudWatch::Alarm
  Properties:
    AlarmName: !Join ['-', [!Ref 'MyService', 'SQSCumulativeAlarm']]
    AlarmDescription: "Trigger ECS Service Scaling based on TWO SQS queues"
    Metrics:
      - Id: e1
        Expression: "fq + sq"
        Label: "Sum of the two Metrics"
      - Id: fq
        MetricStat:
          Metric:
            MetricName: ApproximateNumberOfMessagesVisible
            Namespace: AWS/SQS
            Dimensions:
              - Name: QueueName
                Value: !GetAtt [ FirstQueue, QueueName]
        Period: 60
        Stat: Average
        Unit: Count
        ReturnData: false
      - Id: sq
        MetricStat:
          Metric:
            MetricName: ApproximateNumberOfMessagesVisible
            Namespace: AWS/SQS
            Dimensions:
              - Name: QueueName
                Value: !GetAtt [ SecondQueue, QueueName]
          Period: 60
          Stat: Average
          Unit: Count
        ReturnData: false
    EvaluationPeriods: 2
    Threshold: 100
    ComparisonOperator: GreaterThanThreshold
    AlarmActions:
      - !Ref ECSScaleUp
      - !Ref ECSScaleDown
    OKActions:
      - !Ref ECSScaleUp
      - !Ref ECSScaleDown