AWSTemplateFormatVersion: "2010-09-09"
Description: Sample template for monitoring DynamoDB
Parameters: 
  DynamoDBProvisionedTableName: 
    Description: Name of DynamoDB Provisioned Table to create
    Type: String
    MinLength: 3
    MaxLength: 255
    ConstraintDescription : https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Limits.html#limits-naming-rules
  DynamoDBOnDemandTableName: 
    Description: Name of DynamoDB On-Demand Table to create
    Type: String
    MinLength: 3
    MaxLength: 255
    ConstraintDescription : https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Limits.html#limits-naming-rules
  DynamoDBGlobalTableName: 
    Description: Name of pre-existing DynamoDB Global Table
    Type: String
    MinLength: 3
    MaxLength: 255
    ConstraintDescription : https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Limits.html#limits-naming-rules
  DynamoDBGlobalTableReceivingRegion: 
    Description: Replica Region for Global Table referred to by DynamoDBGlobalTableName
    Type: String
    MinLength: 3
    MaxLength: 255
    ConstraintDescription : https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/Concepts.RegionsAndAvailabilityZones.html
  DynamoDBStreamLambdaFunctionName: 
    Description: DynamoDB Stream Lambda Function Name
    Type: String
    MinLength: 1
    MaxLength: 140
    ConstraintDescription : https://docs.aws.amazon.com/lambda/latest/dg/API_CreateFunction.html
  DynamoDBCustomNamespace: 
    Description : Custom namespace used by DynamoDB Monitoring Lambda
    Type: String
    MinLength: 1
    MaxLength: 255
    ConstraintDescription : https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/cloudwatch_concepts.html
  DynamoDBSNSEmail:
    Description : Email Address subscribed to newly created SNS Topic
    Type: String
    AllowedPattern: "^[a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+\\.[a-zA-Z0-9-.]+$"
    MinLength: 1
    MaxLength: 255

Resources:

  DynamoDBMonitoringSNSTopic:
    Type: AWS::SNS::Topic
    Properties: 
      DisplayName: DynamoDB Monitoring SNS Topic
      Subscription: 
        - Endpoint: !Ref DynamoDBSNSEmail
          Protocol: email
      TopicName: dynamodb-monitoring
  DynamoDBScalingRole: 
    Type: "AWS::IAM::Role"
    Properties: 
     AssumeRolePolicyDocument: 
      Version: "2012-10-17"
      Statement: 
       - 
        Effect: Allow
        Principal: 
         Service: 
          - 
           "application-autoscaling.amazonaws.com"
        Action: 
         - 
          "sts:AssumeRole"
     Path: "/"
     Policies: 
      - 
       PolicyName: root
       PolicyDocument: 
        Version: "2012-10-17"
        Statement: 
         - 
          Effect: Allow
          Action:          
           - "dynamodb:DescribeTable"
           - "dynamodb:UpdateTable"
           - "cloudwatch:PutMetricAlarm"
           - "cloudwatch:DescribeAlarms"
           - "cloudwatch:GetMetricStatistics"
           - "cloudwatch:SetAlarmState"
           - "cloudwatch:DeleteAlarms"
          Resource: "*"

  DynamoDBProvisionedTable:
    Type: "AWS::DynamoDB::Table"
    Properties: 
      TableName: !Ref DynamoDBProvisionedTableName
      AttributeDefinitions: 
        - 
          AttributeName: userId
          AttributeType: S
        - 
          AttributeName: city
          AttributeType: S
        - 
          AttributeName: signupDate
          AttributeType: S
      KeySchema: 
        - 
          AttributeName: userId
          KeyType: HASH
      ProvisionedThroughput: 
        ReadCapacityUnits: 5
        WriteCapacityUnits: 5
      GlobalSecondaryIndexes: 
        - IndexName: !Join [ '-', [!Ref DynamoDBProvisionedTableName, 'gsi1'] ]
          KeySchema: 
            - AttributeName: city
              KeyType: HASH
            - AttributeName: signupDate
              KeyType: RANGE
          Projection: 
            ProjectionType: ALL
          ProvisionedThroughput: 
            ReadCapacityUnits: 5
            WriteCapacityUnits: 5
  ProvisionedTableReadCapacityScalableTarget: 
    Type: "AWS::ApplicationAutoScaling::ScalableTarget"
    Properties: 
      MaxCapacity: 50
      MinCapacity: 10
      ResourceId: !Sub table/${DynamoDBProvisionedTableName}
      RoleARN: !GetAtt DynamoDBScalingRole.Arn
      ScalableDimension: "dynamodb:table:ReadCapacityUnits"
      ServiceNamespace: dynamodb
  ProvisionedTableReadScalingPolicy: 
   Type: "AWS::ApplicationAutoScaling::ScalingPolicy"
   Properties: 
    PolicyName: ReadAutoScalingPolicy
    PolicyType: TargetTrackingScaling
    ScalingTargetId: !Ref ProvisionedTableReadCapacityScalableTarget
    TargetTrackingScalingPolicyConfiguration: 
     TargetValue: 70
     ScaleInCooldown: 60
     ScaleOutCooldown: 60
     PredefinedMetricSpecification: 
      PredefinedMetricType: DynamoDBReadCapacityUtilization
  ProvisionedTableWriteCapacityScalableTarget: 
    Type: "AWS::ApplicationAutoScaling::ScalableTarget"
    Properties: 
      MaxCapacity: 100
      MinCapacity: 5   
      ResourceId: !Sub table/${DynamoDBProvisionedTableName}
      RoleARN: !GetAtt DynamoDBScalingRole.Arn
      ScalableDimension: "dynamodb:table:WriteCapacityUnits"
      ServiceNamespace: dynamodb
  ProvisionedTableWriteScalingPolicy: 
   Type: "AWS::ApplicationAutoScaling::ScalingPolicy"
   Properties: 
    PolicyName: WriteAutoScalingPolicy
    PolicyType: TargetTrackingScaling
    ScalingTargetId: !Ref ProvisionedTableWriteCapacityScalableTarget
    TargetTrackingScalingPolicyConfiguration: 
     TargetValue: 70
     ScaleInCooldown: 60
     ScaleOutCooldown: 60
     PredefinedMetricSpecification: 
      PredefinedMetricType: DynamoDBWriteCapacityUtilization

  DynamoDBOnDemandTable:
    Type: "AWS::DynamoDB::Table"
    Properties: 
      TableName: !Ref DynamoDBOnDemandTableName
      AttributeDefinitions: 
        - 
          AttributeName: userId
          AttributeType: S
        - 
          AttributeName: city
          AttributeType: S
        - 
          AttributeName: signupDate
          AttributeType: S
      KeySchema: 
        - 
          AttributeName: userId
          KeyType: HASH
      BillingMode: PAY_PER_REQUEST
      GlobalSecondaryIndexes: 
        - IndexName: !Join [ '-', [!Ref DynamoDBOnDemandTableName, 'gsi1'] ]
          KeySchema: 
            - AttributeName: city
              KeyType: HASH
            - AttributeName: signupDate
              KeyType: RANGE
          Projection: 
            ProjectionType: ALL

  DynamoDBAccountReadCapAlarm:
    Type: 'AWS::CloudWatch::Alarm'
    Properties:
      AlarmName: 'DynamoDBAccountReadCapAlarm'
      AlarmDescription: 'Alarm when account approaches maximum read capacity limit'
      AlarmActions:
        - !Ref DynamoDBMonitoringSNSTopic
      Namespace: 'AWS/DynamoDB'
      MetricName: 'AccountProvisionedReadCapacityUtilization'
      Statistic: 'Maximum'
      Unit: 'Percent'
      Threshold: 80
      ComparisonOperator: 'GreaterThanThreshold'
      Period: 300
      EvaluationPeriods: 1
  DynamoDBAccountWriteCapAlarm:
    Type: 'AWS::CloudWatch::Alarm'
    Properties:
      AlarmName: 'DynamoDBAccountWriteCapAlarm'
      AlarmDescription: 'Alarm when account approaches maximum write capacity limit'
      AlarmActions:
        - !Ref DynamoDBMonitoringSNSTopic
      Namespace: 'AWS/DynamoDB'
      MetricName: 'AccountProvisionedWriteCapacityUtilization'
      Statistic: 'Maximum'
      Unit: 'Percent'
      Threshold: 80
      ComparisonOperator: 'GreaterThanThreshold'
      Period: 300
      EvaluationPeriods: 1
  DynamoDBTableReadCapAlarm:
    Type: 'AWS::CloudWatch::Alarm'
    Properties:
      AlarmName: 'DynamoDBTableReadCapAlarm'
      AlarmDescription: 'Alarm when table capacity approaches maximum account read capacity limit'
      AlarmActions:
        - !Ref DynamoDBMonitoringSNSTopic
      Namespace: 'AWS/DynamoDB'
      MetricName: 'MaxProvisionedTableReadCapacityUtilization'
      Statistic: 'Maximum'
      Unit: 'Percent'
      Threshold: 80
      ComparisonOperator: 'GreaterThanThreshold'
      Period: 300
      EvaluationPeriods: 1
  DynamoDBTableWriteCapAlarm:
    Type: 'AWS::CloudWatch::Alarm'
    Properties:
      AlarmName: 'DynamoDBTableWriteCapAlarm'
      AlarmDescription: 'Alarm when table capacity approaches maximum account write capacity limit'
      AlarmActions:
        - !Ref DynamoDBMonitoringSNSTopic
      Namespace: 'AWS/DynamoDB'
      MetricName: 'MaxProvisionedTableWriteCapacityUtilization'
      Statistic: 'Maximum'
      Unit: 'Percent'
      Threshold: 80
      ComparisonOperator: 'GreaterThanThreshold'
      Period: 300
      EvaluationPeriods: 1
  DynamoDBAccountTableLimitAlarm:
    Type: 'AWS::CloudWatch::Alarm'
    Properties:
      AlarmName: 'DynamoDBAccountTableLimitAlarm'
      AlarmDescription: 'Alarm when account approaches total limit of number of DynamoDB Tables'
      AlarmActions:
        - !Ref DynamoDBMonitoringSNSTopic
      Namespace: !Ref DynamoDBCustomNamespace
      MetricName: 'AccountTableLimitPct'
      Statistic: 'Maximum'
      Unit: 'Percent'
      Threshold: 80
      ComparisonOperator: 'GreaterThanThreshold'
      Period: 60
      EvaluationPeriods: 2
  DynamoDBTableReadThrottlingAlarm:
    Type: 'AWS::CloudWatch::Alarm'
    Properties:
      AlarmName: 'DynamoDBTableReadThrottlingAlarm'
      AlarmDescription: 'Alarm when table read throttle requests exceed 2% of total number of read requests'
      AlarmActions:
        - !Ref DynamoDBMonitoringSNSTopic
      Metrics:
        - Id: 'e1'
          Expression: '(m1/m2)*100'
          Label: TableReadThrottlesOverTotalReads
        - Id: 'm1'
          MetricStat:
            Metric:
              Namespace: 'AWS/DynamoDB'
              MetricName: 'ReadThrottleEvents'
              Dimensions:
                - Name: 'TableName'
                  Value: !Ref DynamoDBProvisionedTableName
            Period: 60 
            Stat: 'SampleCount'
            Unit: 'Count'
          ReturnData: False
        - Id: 'm2'
          MetricStat:
            Metric:
              Namespace: 'AWS/DynamoDB'
              MetricName: 'ConsumedReadCapacityUnits'
              Dimensions:
                - Name: 'TableName'
                  Value: !Ref DynamoDBProvisionedTableName
            Period: 60 
            Stat: 'SampleCount'
            Unit: 'Count'
          ReturnData: False
      EvaluationPeriods: 2
      Threshold: 2.0
      ComparisonOperator: 'GreaterThanThreshold'
  DynamoDBGSIReadThrottlingAlarm:
    Type: 'AWS::CloudWatch::Alarm'
    Properties:
      AlarmName: 'DynamoDBGSIReadThrottlingAlarm'
      AlarmDescription: 'Alarm when GSI read throttle requests exceed 2% of total number of read requests'
      AlarmActions:
        - !Ref DynamoDBMonitoringSNSTopic
      Metrics:
        - Id: 'e1'
          Expression: '(m1/m2)*100'
          Label: GSIReadThrottlesOverTotalReads
        - Id: 'm1'
          MetricStat:
            Metric:
              Namespace: 'AWS/DynamoDB'
              MetricName: 'ReadThrottleEvents'
              Dimensions:
                - Name: 'TableName'
                  Value: !Ref DynamoDBProvisionedTableName
                - Name: 'GlobalSecondaryIndexName'
                  Value: !Join [ '-', [!Ref DynamoDBProvisionedTableName, 'gsi1'] ]
            Period: 60 
            Stat: 'SampleCount'
            Unit: 'Count'
          ReturnData: False
        - Id: 'm2'
          MetricStat:
            Metric:
              Namespace: 'AWS/DynamoDB'
              MetricName: 'ConsumedReadCapacityUnits'
              Dimensions:
                - Name: 'TableName'
                  Value: !Ref DynamoDBProvisionedTableName
                - Name: 'GlobalSecondaryIndexName'
                  Value: !Join [ '-', [!Ref DynamoDBProvisionedTableName, 'gsi1'] ]
            Period: 60 
            Stat: 'SampleCount'
            Unit: 'Count'
          ReturnData: False
      EvaluationPeriods: 2
      Threshold: 2.0
      ComparisonOperator: 'GreaterThanThreshold'
  DynamoDBTableWriteThrottlingAlarm:
    Type: 'AWS::CloudWatch::Alarm'
    Properties:
      AlarmName: 'DynamoDBTableWriteThrottlingAlarm'
      AlarmDescription: 'Alarm when table write throttle requests exceed 2% of total number of write requests'
      AlarmActions:
        - !Ref DynamoDBMonitoringSNSTopic
      Metrics:
        - Id: 'e1'
          Expression: '(m1/m2)*100'
          Label: TableWriteThrottlesOverTotalWrites
        - Id: 'm1'
          MetricStat:
            Metric:
              Namespace: 'AWS/DynamoDB'
              MetricName: 'WriteThrottleEvents'
              Dimensions:
                - Name: 'TableName'
                  Value: !Ref DynamoDBProvisionedTableName
            Period: 60 
            Stat: 'SampleCount'
            Unit: 'Count'
          ReturnData: False
        - Id: 'm2'
          MetricStat:
            Metric:
              Namespace: 'AWS/DynamoDB'
              MetricName: 'ConsumedWriteCapacityUnits'
              Dimensions:
                - Name: 'TableName'
                  Value: !Ref DynamoDBProvisionedTableName
            Period: 60 
            Stat: 'SampleCount'
            Unit: 'Count'
          ReturnData: False
      EvaluationPeriods: 2
      Threshold: 2.0
      ComparisonOperator: 'GreaterThanThreshold'
  DynamoDBGSIWriteThrottlingAlarm:
    Type: 'AWS::CloudWatch::Alarm'
    Properties:
      AlarmName: 'DynamoDBGSIWriteThrottlingAlarm'
      AlarmDescription: 'Alarm when GSI write throttle requests exceed 2% of total number of write requests'
      AlarmActions:
        - !Ref DynamoDBMonitoringSNSTopic
      Metrics:
        - Id: 'e1'
          Expression: '(m1/m2)*100'
          Label: GSIWriteThrottlesOverTotalWrites
        - Id: 'm1'
          MetricStat:
            Metric:
              Namespace: 'AWS/DynamoDB'
              MetricName: 'WriteThrottleEvents'
              Dimensions:
                - Name: 'TableName'
                  Value: !Ref DynamoDBProvisionedTableName
                - Name: 'GlobalSecondaryIndexName'
                  Value: !Join [ '-', [!Ref DynamoDBProvisionedTableName, 'gsi1'] ]
            Period: 60 
            Stat: 'SampleCount'
            Unit: 'Count'
          ReturnData: False
        - Id: 'm2'
          MetricStat:
            Metric:
              Namespace: 'AWS/DynamoDB'
              MetricName: 'ConsumedWriteCapacityUnits'
              Dimensions:
                - Name: 'TableName'
                  Value: !Ref DynamoDBProvisionedTableName
                - Name: 'GlobalSecondaryIndexName'
                  Value: !Join [ '-', [!Ref DynamoDBProvisionedTableName, 'gsi1'] ]
            Period: 60 
            Stat: 'SampleCount'
            Unit: 'Count'
          ReturnData: False
      EvaluationPeriods: 2
      Threshold: 2.0
      ComparisonOperator: 'GreaterThanThreshold'
  DynamoDBTableSystemErrorAlarm:
    Type: 'AWS::CloudWatch::Alarm'
    Properties:
      AlarmName: 'DynamoDBTableSystemErrorAlarm'
      AlarmDescription: 'Alarm when system errors exceed 2% of total number of requests'
      AlarmActions:
        - !Ref DynamoDBMonitoringSNSTopic
      Metrics:
        - Id: 'e1'
          Expression: 'm1/(m2+m3)'
          Label: SystemErrorsOverTotalRequests
        - Id: 'm1'
          MetricStat:
            Metric:
              Namespace: 'AWS/DynamoDB'
              MetricName: 'SystemErrors'
              Dimensions:
                - Name: 'TableName'
                  Value: !Ref DynamoDBProvisionedTableName
            Period: 60 
            Stat: 'SampleCount'
            Unit: 'Count'
          ReturnData: False
        - Id: 'm2'
          MetricStat:
            Metric:
              Namespace: 'AWS/DynamoDB'
              MetricName: 'ConsumedReadCapacityUnits'
              Dimensions:
                - Name: 'TableName'
                  Value: !Ref DynamoDBProvisionedTableName
            Period: 60 
            Stat: 'SampleCount'
            Unit: 'Count'
          ReturnData: False
        - Id: 'm3'
          MetricStat:
            Metric:
              Namespace: 'AWS/DynamoDB'
              MetricName: 'ConsumedWriteCapacityUnits'
              Dimensions:
                - Name: 'TableName'
                  Value: !Ref DynamoDBProvisionedTableName
            Period: 60 
            Stat: 'SampleCount'
            Unit: 'Count'
          ReturnData: False
      EvaluationPeriods: 20
      Threshold: 2.0
      ComparisonOperator: 'GreaterThanThreshold'
  DynamoDBGSISystemErrorAlarm:
    Type: 'AWS::CloudWatch::Alarm'
    Properties:
      AlarmName: 'DynamoDBGSISystemErrorAlarm'
      AlarmDescription: 'Alarm when GSI system errors exceed 2% of total number of requests'
      AlarmActions:
        - !Ref DynamoDBMonitoringSNSTopic
      Metrics:
        - Id: 'e1'
          Expression: 'm1/(m2+m3)'
          Label: GSISystemErrorsOverTotalRequests
        - Id: 'm1'
          MetricStat:
            Metric:
              Namespace: 'AWS/DynamoDB'
              MetricName: 'SystemErrors'
              Dimensions:
                - Name: 'TableName'
                  Value: !Ref DynamoDBProvisionedTableName
                - Name: 'GlobalSecondaryIndexName'
                  Value: !Join [ '-', [!Ref DynamoDBProvisionedTableName, 'gsi1'] ]
            Period: 60 
            Stat: 'SampleCount'
            Unit: 'Count'
          ReturnData: False
        - Id: 'm2'
          MetricStat:
            Metric:
              Namespace: 'AWS/DynamoDB'
              MetricName: 'ConsumedReadCapacityUnits'
              Dimensions:
                - Name: 'TableName'
                  Value: !Ref DynamoDBProvisionedTableName
                - Name: 'GlobalSecondaryIndexName'
                  Value: !Join [ '-', [!Ref DynamoDBProvisionedTableName, 'gsi1'] ]
            Period: 60 
            Stat: 'SampleCount'
            Unit: 'Count'
          ReturnData: False
        - Id: 'm3'
          MetricStat:
            Metric:
              Namespace: 'AWS/DynamoDB'
              MetricName: 'ConsumedWriteCapacityUnits'
              Dimensions:
                - Name: 'TableName'
                  Value: !Ref DynamoDBProvisionedTableName
                - Name: 'GlobalSecondaryIndexName'
                  Value: !Join [ '-', [!Ref DynamoDBProvisionedTableName, 'gsi1'] ]
            Period: 60 
            Stat: 'SampleCount'
            Unit: 'Count'
          ReturnData: False
      EvaluationPeriods: 20
      Threshold: 2.0
      ComparisonOperator: 'GreaterThanThreshold'
  DynamoDBTableUserErrorAlarm:
    Type: 'AWS::CloudWatch::Alarm'
    Properties:
      AlarmName: 'DynamoDBTableUserErrorAlarm'
      AlarmDescription: 'Alarm when user errors exceed 2% of total number of requests'
      AlarmActions:
        - !Ref DynamoDBMonitoringSNSTopic
      Metrics:
        - Id: 'e1'
          Expression: 'm1/(m2+m3)'
          Label: UserErrorsOverTotalRequests
        - Id: 'm1'
          MetricStat:
            Metric:
              Namespace: 'AWS/DynamoDB'
              MetricName: 'UserErrors'
              Dimensions:
                - Name: 'TableName'
                  Value: !Ref DynamoDBProvisionedTableName
            Period: 60 
            Stat: 'SampleCount'
            Unit: 'Count'
          ReturnData: False
        - Id: 'm2'
          MetricStat:
            Metric:
              Namespace: 'AWS/DynamoDB'
              MetricName: 'ConsumedReadCapacityUnits'
              Dimensions:
                - Name: 'TableName'
                  Value: !Ref DynamoDBProvisionedTableName
            Period: 60 
            Stat: 'SampleCount'
            Unit: 'Count'
          ReturnData: False
        - Id: 'm3'
          MetricStat:
            Metric:
              Namespace: 'AWS/DynamoDB'
              MetricName: 'ConsumedWriteCapacityUnits'
              Dimensions:
                - Name: 'TableName'
                  Value: !Ref DynamoDBProvisionedTableName
            Period: 60 
            Stat: 'SampleCount'
            Unit: 'Count'
          ReturnData: False
      EvaluationPeriods: 2
      Threshold: 2.0
      ComparisonOperator: 'GreaterThanThreshold'
  DynamoDBGSIUserErrorAlarm:
    Type: 'AWS::CloudWatch::Alarm'
    Properties:
      AlarmName: 'DynamoDBGSIUserErrorAlarm'
      AlarmDescription: 'Alarm when GSI user errors exceed 2% of total number of requests'
      AlarmActions:
        - !Ref DynamoDBMonitoringSNSTopic
      Metrics:
        - Id: 'e1'
          Expression: 'm1/(m2+m3)'
          Label: GSIUserErrorsOverTotalRequests
        - Id: 'm1'
          MetricStat:
            Metric:
              Namespace: 'AWS/DynamoDB'
              MetricName: 'UserErrors'
              Dimensions:
                - Name: 'TableName'
                  Value: !Ref DynamoDBProvisionedTableName
                - Name: 'GlobalSecondaryIndexName'
                  Value: !Join [ '-', [!Ref DynamoDBProvisionedTableName, 'gsi1'] ]
            Period: 60 
            Stat: 'SampleCount'
            Unit: 'Count'
          ReturnData: False
        - Id: 'm2'
          MetricStat:
            Metric:
              Namespace: 'AWS/DynamoDB'
              MetricName: 'ConsumedReadCapacityUnits'
              Dimensions:
                - Name: 'TableName'
                  Value: !Ref DynamoDBProvisionedTableName
                - Name: 'GlobalSecondaryIndexName'
                  Value: !Join [ '-', [!Ref DynamoDBProvisionedTableName, 'gsi1'] ]
            Period: 60 
            Stat: 'SampleCount'
            Unit: 'Count'
          ReturnData: False
        - Id: 'm3'
          MetricStat:
            Metric:
              Namespace: 'AWS/DynamoDB'
              MetricName: 'ConsumedWriteCapacityUnits'
              Dimensions:
                - Name: 'TableName'
                  Value: !Ref DynamoDBProvisionedTableName
                - Name: 'GlobalSecondaryIndexName'
                  Value: !Join [ '-', [!Ref DynamoDBProvisionedTableName, 'gsi1'] ]
            Period: 60 
            Stat: 'SampleCount'
            Unit: 'Count'
          ReturnData: False
      EvaluationPeriods: 2
      Threshold: 2.0
      ComparisonOperator: 'GreaterThanThreshold'
  DynamoDBTableConditionCheckAlarm:
    Type: 'AWS::CloudWatch::Alarm'
    Properties:
      AlarmName: 'DynamoDBTableConditionCheckWritelarm'
      AlarmDescription: 'Alarm when condition check errors are too high'
      AlarmActions:
        - !Ref DynamoDBMonitoringSNSTopic
      Namespace: 'AWS/DynamoDB'
      MetricName: 'ConditionalCheckFailedRequests'
      Statistic: 'Sum'
      Unit: 'Count'
      Threshold: 100
      ComparisonOperator: 'GreaterThanThreshold'
      Period: 60
      EvaluationPeriods: 2
  DynamoDBTableTransactionConflictAlarm:
    Type: 'AWS::CloudWatch::Alarm'
    Properties:
      AlarmName: 'DynamoDBTableTransactionConflictAlarm'
      AlarmDescription: 'Alarm when transaction conflict errors are too high'
      AlarmActions:
        - !Ref DynamoDBMonitoringSNSTopic
      Namespace: 'AWS/DynamoDB'
      MetricName: 'TransactionConflict'
      Statistic: 'Sum'
      Unit: 'Count'
      Threshold: 100
      ComparisonOperator: 'GreaterThanThreshold'
      Period: 60
      EvaluationPeriods: 2
  DynamoDBTableASReadAlarm:
    Type: 'AWS::CloudWatch::Alarm'
    Properties:
      AlarmName: 'DynamoDBTableASReadAlarm'
      AlarmDescription: 'Alarm when table auto scaling read setting approaches table AS maximum'
      AlarmActions:
        - !Ref DynamoDBMonitoringSNSTopic
      Namespace: !Ref DynamoDBCustomNamespace
      MetricName: 'ProvisionedReadCapacityAutoScalingPct'
      Dimensions:
        - Name: 'TableName'
          Value: !Ref DynamoDBProvisionedTableName
      Statistic: 'Maximum'
      Unit: 'Percent'
      Threshold: 90
      ComparisonOperator: 'GreaterThanThreshold'
      Period: 60
      EvaluationPeriods: 2
  DynamoDBTableASWriteAlarm:
    Type: 'AWS::CloudWatch::Alarm'
    Properties:
      AlarmName: 'DynamoDBTableASWriteAlarm'
      AlarmDescription: 'Alarm when table auto scaling write setting approaches table AS maximum'
      AlarmActions:
        - !Ref DynamoDBMonitoringSNSTopic
      Namespace: !Ref DynamoDBCustomNamespace
      MetricName: 'ProvisionedWriteCapacityAutoScalingPct'
      Dimensions:
        - Name: 'TableName'
          Value: !Ref DynamoDBProvisionedTableName
      Statistic: 'Maximum'
      Unit: 'Percent'
      Threshold: 90
      ComparisonOperator: 'GreaterThanThreshold'
      Period: 60
      EvaluationPeriods: 2

# Alarms for OnDemand Tables
  DynamoDBOnDemandTableReadLimitAlarm:
    Type: 'AWS::CloudWatch::Alarm'
    Properties:
      AlarmName: 'DynamoDBOnDemandTableReadLimitAlarm'
      AlarmDescription: 'Alarm when consumed table reads approach the account limit'
      AlarmActions:
        - !Ref DynamoDBMonitoringSNSTopic
      Metrics:
        - Id: 'e1'
          Expression: '(((m1 / 300) / m2) * 100)'
          Label: TableReadsOverMaxReadLimit
        - Id: 'm1'
          MetricStat:
            Metric:
              Namespace: 'AWS/DynamoDB'
              MetricName: 'ConsumedReadCapacityUnits'
              Dimensions:
                - Name: 'TableName'
                  Value: !Ref DynamoDBOnDemandTableName
            Period: 300 
            Stat: 'SampleCount'
            Unit: 'Count'
          ReturnData: False
        - Id: 'm2'
          MetricStat:
            Metric:
              Namespace: 'AWS/DynamoDB'
              MetricName: 'AccountMaxTableLevelReads'
            Period: 300 
            Stat: 'Maximum'
          ReturnData: False
      EvaluationPeriods: 2
      Threshold: 90
      ComparisonOperator: 'GreaterThanThreshold'

  DynamoDBOnDemandTableWriteLimitAlarm:
    Type: 'AWS::CloudWatch::Alarm'
    Properties:
      AlarmName: 'DynamoDBOnDemandTableWriteLimitAlarm'
      AlarmDescription: 'Alarm when consumed table reads approach the account limit'
      AlarmActions:
        - !Ref DynamoDBMonitoringSNSTopic
      Metrics:
        - Id: 'e1'
          Expression: '(((m1 / 300) / m2) * 100)'
          Label: TableWritesOverMaxWriteLimit
        - Id: 'm1'
          MetricStat:
            Metric:
              Namespace: 'AWS/DynamoDB'
              MetricName: 'ConsumedWriteCapacityUnits'
              Dimensions:
                - Name: 'TableName'
                  Value: !Ref DynamoDBOnDemandTableName
            Period: 300 
            Stat: 'SampleCount'
            Unit: 'Count'
          ReturnData: False
        - Id: 'm2'
          MetricStat:
            Metric:
              Namespace: 'AWS/DynamoDB'
              MetricName: 'AccountMaxTableLevelWrites'
            Period: 300 
            Stat: 'Maximum'
          ReturnData: False
      EvaluationPeriods: 2
      Threshold: 90
      ComparisonOperator: 'GreaterThanThreshold'

  DynamoDBOnDemandGSIReadLimitAlarm:
    Type: 'AWS::CloudWatch::Alarm'
    Properties:
      AlarmName: 'DynamoDBOnDemandGSIReadLimitAlarm'
      AlarmDescription: 'Alarm when consumed GSI reads approach the account limit'
      AlarmActions:
        - !Ref DynamoDBMonitoringSNSTopic
      Metrics:
        - Id: 'e1'
          Expression: '(((m1 / 300) / m2) * 100)'
          Label: GSIReadsOverMaxReadLimit
        - Id: 'm1'
          MetricStat:
            Metric:
              Namespace: 'AWS/DynamoDB'
              MetricName: 'ConsumedReadCapacityUnits'
              Dimensions:
                - Name: 'TableName'
                  Value: !Ref DynamoDBOnDemandTableName
                - Name: 'GlobalSecondaryIndexName'
                  Value: !Join [ '-', [!Ref DynamoDBOnDemandTableName, 'gsi1'] ]
            Period: 300 
            Stat: 'SampleCount'
            Unit: 'Count'
          ReturnData: False
        - Id: 'm2'
          MetricStat:
            Metric:
              Namespace: 'AWS/DynamoDB'
              MetricName: 'AccountMaxTableLevelReads'
            Period: 300 
            Stat: 'Maximum'
          ReturnData: False
      EvaluationPeriods: 2
      Threshold: 90
      ComparisonOperator: 'GreaterThanThreshold'

  DynamoDBOnDemandGSIWriteLimitAlarm:
    Type: 'AWS::CloudWatch::Alarm'
    Properties:
      AlarmName: 'DynamoDBOnDemandGSIWriteLimitAlarm'
      AlarmDescription: 'Alarm when consumed GSI reads approach the account limit'
      AlarmActions:
        - !Ref DynamoDBMonitoringSNSTopic
      Metrics:
        - Id: 'e1'
          Expression: '(((m1 / 300) / m2) * 100)'
          Label: GSIWritesOverMaxWriteLimit
        - Id: 'm1'
          MetricStat:
            Metric:
              Namespace: 'AWS/DynamoDB'
              MetricName: 'ConsumedWriteCapacityUnits'
              Dimensions:
                - Name: 'TableName'
                  Value: !Ref DynamoDBOnDemandTableName
                - Name: 'GlobalSecondaryIndexName'
                  Value: !Join [ '-', [!Ref DynamoDBOnDemandTableName, 'gsi1'] ]
            Period: 300 
            Stat: 'SampleCount'
            Unit: 'Count'
          ReturnData: False
        - Id: 'm2'
          MetricStat:
            Metric:
              Namespace: 'AWS/DynamoDB'
              MetricName: 'AccountMaxTableLevelWrites'
            Period: 300 
            Stat: 'Maximum'
          ReturnData: False
      EvaluationPeriods: 2
      Threshold: 90
      ComparisonOperator: 'GreaterThanThreshold'

# Alarms for Global Tables
  DynamoDBGTReplLatencyAlarm:
    Type: 'AWS::CloudWatch::Alarm'
    Properties:
      AlarmName: 'DynamoDBGTReplLatencyAlarm'
      AlarmDescription: 'Alarm when global table replication latency exceeds 3 minutes (180k ms)'
      AlarmActions:
        - !Ref DynamoDBMonitoringSNSTopic
      Namespace: 'AWS/DynamoDB'
      MetricName: 'ReplicationLatency'
      Dimensions:
        - Name: 'TableName'
          Value: !Ref DynamoDBGlobalTableName
        - Name: 'ReceivingRegion'
          Value: !Ref DynamoDBGlobalTableReceivingRegion
      Statistic: 'Average'
      Threshold: 180000
      ComparisonOperator: 'GreaterThanThreshold'
      Period: 60
      EvaluationPeriods: 15

# Alarms for Lambda Functions
  DynamoStreamLambdaIteratorAgeAlarm:
    Type: 'AWS::CloudWatch::Alarm'
    Properties:
      AlarmName: 'DynamoStreamLambdaIteratorAgeAlarm'
      AlarmDescription: 'Alarm when lambda iterator age exceeds 30 seconds (30k ms)'
      AlarmActions:
        - !Ref DynamoDBMonitoringSNSTopic
      Namespace: 'AWS/Lambda'
      MetricName: 'IteratorAge'
      Dimensions:
        - Name: 'Function'
          Value: !Ref DynamoDBStreamLambdaFunctionName
        - Name: 'Resource'
          Value: !Ref DynamoDBStreamLambdaFunctionName
      Statistic: 'Average'
      Threshold: 30000
      ComparisonOperator: 'GreaterThanThreshold'
      Period: 60
      EvaluationPeriods: 2