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AWS DynamoDB Click here for latest

Scale applications based on the records count in AWS DynamoDB

Availability: v2.7+ Maintainer: Community
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Trigger Specification

This specification describes the AWS DynamoDB scaler. This scaler uses a specified DynamoDB query to determine if and when to scale a given workload.

triggers: - type: aws-dynamodb  metadata:  # Required: awsRegion  awsRegion: "eu-west-1"  # Required: tableName  tableName: myTableName  # Required: targetValue  targetValue: "1"  # Required: expressionAttributeNames  expressionAttributeNames: '{ "#k" : "partition_key_name"}'  # Required: keyConditionExpression  keyConditionExpression: "#k = :key"  # Required: expressionAttributeValues  expressionAttributeValues: '{ ":key" : {"S":"partition_key_target_value"}}'  # Optional. Default: pod  identityOwner: pod | operator

Parameter list:

  • awsRegion - AWS Region for the DynamoDB Table.
  • tableName - The target table where the scaler execute the query.
  • targetValue - The target value for the number of items retrieved by the query.
  • activationTargetValue - Target value for activating the scaler. Learn more about activation here. (Default: 0, Optional)
  • expressionAttributeNames - one or more substitution tokens for attribute names in an expression. Defined as JSON.
  • keyConditionExpression - the condition that specifies the key values for items to be retrieved by the Query action.
  • expressionAttributeValues - one or more values that can be substituted in an expression. Defined as JSON.
  • identityOwner - Receive permissions on the DynamoDB Table via Pod Identity or from the KEDA operator itself (see below). (Values: pod, operator, Default: pod, Optional)

When identityOwner set to operator - the only requirement is that the KEDA operator has the correct IAM permissions on the DynamoDB Table. Additional Authentication Parameters are not required.

Authentication Parameters

These parameters are relevant only when identityOwner is set to pod.

You can use TriggerAuthentication CRD to configure the authenticate by providing either a role ARN or a set of IAM credentials.

Pod identity based authentication:

  • podIdentity.provider - Needs to be set to either aws-kiam or aws-eks on the TriggerAuthentication and the pod/service account must be configured correctly for your pod identity provider.

Role based authentication:

  • awsRoleArn - Amazon Resource Names (ARNs) uniquely identify AWS resource.

Credential based authentication:

  • awsAccessKeyID - Id of the user.
  • awsSecretAccessKey - Access key for the user to authenticate with.
  • awsSessionToken - Session token, only required when using temporary credentials.

The user will need access to read properties from the specified AWS SQS queue.

Example

Scaling a deployment using IAM Role 

apiVersion: v1 kind: Secret metadata:  name: test-secrets data:  AWS_ROLE_ARN: <encoded-iam-role-arn> --- apiVersion: keda.sh/v1alpha1 kind: TriggerAuthentication metadata:  name: keda-trigger-auth-aws-credentials  namespace: default spec:  secretTargetRef:  - parameter: awsRoleArn # The property in KEDA.  name: test-secrets # The name of the kubernetes secret.  key: AWS_ROLE_ARN # The key from the kubernetes secret. --- apiVersion: keda.sh/v1alpha1 kind: ScaledObject metadata:  name: aws-dynamodb-table-scaledobject  namespace: keda-test spec:  scaleTargetRef:  name: nginx-deployment  triggers:  - type: aws-dynamodb  authenticationRef:  name: keda-trigger-auth-aws-credentials  metadata:  awsRegion: eu-west-2  tableName: keda-events  expressionAttributeNames: '{ "#k" : "event_type"}'  keyConditionExpression: "#k = :key"  expressionAttributeValues: '{ ":key" : {"S":"scaling_event"}}'  targetValue: "5"

Scaling a deployment using IAM Users 

apiVersion: v1 kind: Secret metadata:  name: test-secrets data:  AWS_ACCESS_KEY_ID: <encoded-user-id> # Required.  AWS_SECRET_ACCESS_KEY: <encoded-key> # Required.  AWS_SESSION_TOKEN: <encoded-session-token> # Required when using temporary credentials. --- apiVersion: keda.sh/v1alpha1 kind: TriggerAuthentication metadata:  name: keda-trigger-auth-aws-credentials  namespace: default spec:  secretTargetRef:  - parameter: awsAccessKeyID # Required.  name: test-secrets # Required.  key: AWS_ACCESS_KEY_ID # Required.  - parameter: awsSecretAccessKey # Required.  name: test-secrets # Required.  key: AWS_SECRET_ACCESS_KEY # Required.  - parameter: awsSessionToken # Required when using temporary credentials.  name: test-secrets # Required when using temporary credentials.  key: AWS_SESSION_TOKEN # Required when using temporary credentials. --- apiVersion: keda.sh/v1alpha1 kind: ScaledObject metadata:  name: aws-dynamodb-table-scaledobject  namespace: keda-test spec:  scaleTargetRef:  name: nginx-deployment  triggers:  - type: aws-dynamodb  authenticationRef:  name: keda-trigger-auth-aws-credentials  metadata:  awsRegion: eu-west-2  tableName: keda-events  expressionAttributeNames: '{ "#k" : "event_type"}'  keyConditionExpression: "#k = :key"  expressionAttributeValues: '{ ":key" : {"S":"scaling_event"}}'  targetValue: "5"