AWS DynamoDB

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"
    # Optional: awsEndpoint
    awsEndpoint: ""
    # Required: tableName
    tableName: myTableName
    # Optional: indexName
    indexName: ""
    # 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"}}'
    # DEPRECATED: This parameter is deprecated as of KEDA v2.13 and will be removed in v3. Optional # Optional. Default: pod
    identityOwner: pod | operator

Parameter list:

awsRegion - AWS Region for the DynamoDB Table.
awsEndpoint - Endpoint URL to override the default AWS endpoint. (Default: "", Optional)
tableName - The target table where the scaler execute the query.
indexName - The index used by the DynamoDB Query. (Optional)
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). (DEPRECATED: This parameter is deprecated as of KEDA v2.13 and will be removed in version 3, Values: pod, operator, Default: pod, Optional, This field only applies for aws-eks authentication)

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

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 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. (This field is deprecated and only applies for aws-eks authentication, for aws is set in the auth)

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"