@aws-solutions-constructs/aws-dynamodbstreams-lambda

aws-dynamodbstreams-lambda module

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All classes are under active development and subject to non-backward compatible changes or removal in any future version. These are not subject to the Semantic Versioning model. This means that while you may use them, you may need to update your source code when upgrading to a newer version of this package.

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Reference Documentation:	https://docs.aws.amazon.com/solutions/latest/constructs/

Language	Package
Python	aws_solutions_constructs.aws_dynamodbstreams_lambda
Typescript	@aws-solutions-constructs/aws-dynamodbstreams-lambda
Java	software.amazon.awsconstructs.services.dynamodbstreamslambda

This AWS Solutions Construct implements a pattern Amazon DynamoDB table with stream to invoke the AWS Lambda function with the least privileged permissions.

Here is a minimal deployable pattern definition in Typescript:

import { DynamoDBStreamsToLambdaProps,  DynamoDBStreamsToLambda} from '@aws-solutions-constructs/aws-dynamodbstreams-lambda';

new DynamoDBStreamsToLambda(this, 'test-dynamodbstreams-lambda', {
  lambdaFunctionProps: {
      code: lambda.Code.fromAsset(`${__dirname}/lambda`),
      runtime: lambda.Runtime.NODEJS_14_X,
      handler: 'index.handler'
  },
});

Initializer

new DynamoDBStreamsToLambda(scope: Construct, id: string, props: DynamoDBStreamsToLambdaProps);

Parameters

• scope Construct
• id string
• props DynamoDBStreamsToLambdaProps

Pattern Construct Props

Name	Type	Description
existingLambdaObj?	lambda.Function	Existing instance of Lambda Function object, providing both this and lambdaFunctionProps will cause an error.
lambdaFunctionProps?	lambda.FunctionProps	User provided props to override the default props for the Lambda function.
dynamoTableProps?	dynamodb.TableProps	Optional user provided props to override the default props for DynamoDB Table
existingTableInterface?	dynamodb.ITable	Existing instance of DynamoDB table object or interface, providing both this and dynamoTableProps will cause an error.
dynamoEventSourceProps?	aws-lambda-event-sources.DynamoEventSourceProps	Optional user provided props to override the default props for DynamoDB Event Source

Pattern Properties

Name	Type	Description
dynamoTableInterface	dynamodb.ITable	Returns an instance of dynamodb.ITable created by the construct
dynamoTable?	dynamodb.Table	Returns an instance of dynamodb.Table created by the construct. IMPORTANT: If existingTableInterface was provided in Pattern Construct Props, this property will be undefined
lambdaFunction	lambda.Function	Returns an instance of lambda.Function created by the construct

Lambda Function

This pattern requires a lambda function that can post data into the Elasticsearch. A sample function is provided here.

Default settings

Out of the box implementation of the Construct without any override will set the following defaults:

Amazon DynamoDB Table

• Set the billing mode for DynamoDB Table to On-Demand (Pay per request)
• Enable server-side encryption for DynamoDB Table using AWS managed KMS Key
• Creates a partition key called 'id' for DynamoDB Table
• Retain the Table when deleting the CloudFormation stack
• Enable continuous backups and point-in-time recovery

AWS Lambda Function

• Configure limited privilege access IAM role for Lambda function
• Enable reusing connections with Keep-Alive for NodeJs Lambda function
• Enable X-Ray Tracing
• Enable Failure-Handling features like enable bisect on function Error, set defaults for Maximum Record Age (24 hours) & Maximum Retry Attempts (500) and deploy SQS dead-letter queue as destination on failure
• Set Environment Variables
  • AWS_NODEJS_CONNECTION_REUSE_ENABLED (for Node 10.x and higher functions)

Architecture

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