To subscribe to the dynamodb global table stream in regional aws lambdas?

Question

Here is my regional lambda sdk configuration.

The problem is tableStreamArn it seems:

   const globalTableTableName = "my-org-glb-table1"

    const regionalTable = Table.fromTableAttributes(this, `Table-${Stack.of(this).region}`, {
        tableName: globalTableTableName,
        tableStreamArn: `arn:aws:dynamodb:${Stack.of(this).region}:${this.account}:table/${globalTableTableName}/stream/latest` // here !
    });

    const eventSource = new DynamoEventSource(regionalTable, {
        startingPosition: StartingPosition.TRIM_HORIZON,
        batchSize: 5,
        bisectBatchOnError: true,
        retryAttempts: 2
    });
    lambda1.addEventSource(eventSource);

I can not know what stream the table will have, so my lambda stack fail to deploy.

Having the stream/latest - would not work:

❌ Deployment failed: Error: The stack named app-my-org-lambda-stack failed creation, it may need to be manually deleted from the AWS console: ROLLBACK_COMPLETE: Resource handler returned message: "Invalid request provided: Stream not found: arn:aws:dynamodb:us-east-1:123456789012:table/app-my-org-glb-table1/stream/latest (Service: Lambda, Status Code: 400, Request ID: e165f9e7-f808-4528-b383-4992861e5aa0)" (RequestToken: d98d6f65-21d1-80b0-4ab3-7a3fc9430268, HandlerErrorCode: InvalidRequest)

Unless I am doing it wrong, I've checked this and that:

• What happens to DynamoDB stream when we convert regional table to global table
• DynamoDB Global Table replication stream event issues

That sounds good, but how to make it work?

P.S. I used L1 construct to create global table, and tested that it is deploy-able and stream is on there (with some ARN).

if(stackRegion == PRIMARY_REGION) {

            const globalTable = new CfnGlobalTable(this, 'my-org-glb-table1', {
                tableName: "my-org-glb-table1",
                ...

Answer 1

Ok. the idea came from this answer.

How I did this with the CKD, is like that (and btw GPT failed on that):

const globalTableTableName = "my-org-glb-table1"

    // getting the stream arn for the table
    const streamArnProvider = this.getStreamArnProviderService(props.lambdaStreamArnProviderArn, ecrRepo);
    const streamArnResource = new CustomResource(this, 'StreamArnResource', {
        serviceToken: streamArnProvider.serviceToken,
        properties: {
            TableName: globalTableTableName // this is where we pass table name to the lambda
        }
    });
    const streamArn = streamArnResource.getAtt('StreamArn').toString();
 const regionalTable = Table.fromTableAttributes(this, `${globalTableTableName}-${Stack.of(this).region}`, {
        tableName: globalTableTableName,
        tableStreamArn: streamArn
    });

where:

 private getStreamArnProviderService(streamArnProviderLambdaArn: string, ecrRepo: IRepository): Provider {

    const streamArnProviderLambda = lambda.Function.fromFunctionAttributes(this, 'ImportedLambda', {
        functionArn: streamArnProviderLambdaArn,
        // true, since the Lambda function is in the same environment and we want CDK to manage permissions
        sameEnvironment: true
    });

    return new Provider(this, 'StreamArnProviderService', {
        onEventHandler: streamArnProviderLambda,
    });
}

Basically by introducing +1 lambda that were getting the ARN from the table's ARN per region.

And the streamArnProviderLambdaArn comes from another stack that crates that streamArnProviderLambda