如何使用Cloudformation模板对dynamodb二级索引进行自动调整？

Question

我已经看到了向具有cloudformation的表添加自动缩放的示例，但除了dynamodb控制台中的“将相同设置应用于全局二级索引”复选框之外，我没有看到使用cloudformation模板定义此方法的方法。

Answer 1

It is possible to define the secondary index as an autoscaling target.

You need just to specify the index as the resourceId using /index/**YOUR_INDEX_NAME** as a suffix and using dynamodb:index:WriteCapacityUnits and dynamodb:index:ReadCapacityUnits as ScalableDimension .

Eg

  SecIndexWriteCapacity:
    Type: AWS::ApplicationAutoScaling::ScalableTarget
    Properties:
      MaxCapacity: 1000
      MinCapacity: 15
      ResourceId: !Sub "table/${MY_MAIN_TABLE}/index/${MY_SECONDARY_INDEX_NAME}"
      RoleARN: !GetAtt ScalingRole.Arn
      ScalableDimension: dynamodb:index:WriteCapacityUnits
      ServiceNamespace: dynamodb
  SecIndexReadCapacity:
    Type: AWS::ApplicationAutoScaling::ScalableTarget
    Properties:
      MaxCapacity: 1000
      MinCapacity: 15
      ResourceId: !Sub "table/${MY_MAIN_TABLE}/index/MY_SECONDARY_INDEX_NAME"
      RoleARN: !GetAtt ScalingRole.Arn
      ScalableDimension: dynamodb:index:ReadCapacityUnits
      ServiceNamespace: dynamodb
  SecIndexWriteScalingPolicy:
    Type: AWS::ApplicationAutoScaling::ScalingPolicy
    Properties:
      PolicyName: SecIndexWriteScalingPolicy
      PolicyType: TargetTrackingScaling
      ScalingTargetId: !Ref SecIndexWriteCapacity
      TargetTrackingScalingPolicyConfiguration:
        TargetValue: 50.0
        ScaleInCooldown: 30
        ScaleOutCooldown: 1
        PredefinedMetricSpecification:
          PredefinedMetricType: DynamoDBWriteCapacityUtilization
  SecIndexReadScalingPolicy:
    Type: AWS::ApplicationAutoScaling::ScalingPolicy
    Properties:
      PolicyName: SecIndexReadScalingPolicy
      PolicyType: TargetTrackingScaling
      ScalingTargetId: !Ref SecIndexReadCapacity
      TargetTrackingScalingPolicyConfiguration:
        TargetValue: 50.0
        ScaleInCooldown: 30
        ScaleOutCooldown: 0
        PredefinedMetricSpecification:
          PredefinedMetricType: DynamoDBReadCapacityUtilization

See also https://aws.amazon.com/blogs/database/how-to-use-aws-cloudformation-to-configure-auto-scaling-for-amazon-dynamodb-tables-and-indexes/

Answer 2

Actually it is possible.

Follow the official AWS example for the DynamoDB/CloudFormation , but for each GSI you would need to create a separate ScalableTarget and a Scalable Policy. In the ScalableTarget properties use table/my-table/index/my-table-index notation for the ResourceId.