TableV2: TableV2 Replica provides the incorrect TableStreamARN in CDK

[kevinhuynh23]

Describe the bug

When using Global Tables with TableV2 in CDK, the replica tables aren't referenced properly with an output export like the primary Global Table Stream ARN. For example, we create a global table in us-east-1 with replicas in us-west-2 and eu-west-1.

When getting the Stream ARN for the primary global table, CDK will create reference the exact Stream ARN i.e. arn:aws:dynamodb:us-east-1:123456789012:table/IndraMembershipDetails-Beta/stream/<timestamp>. Where as in the replica tables when using globalTable.replica("us-west-2"), it'll get the correct replica table, but the Stream ARN provided is not the exact Stream ARN, but something like this instead: arn:aws:dynamodb:us-west-2:123456789012:table/IndraMembershipDetails-Beta/stream/*.

Regression Issue

• Select this option if this issue appears to be a regression.

Last Known Working CDK Version

No response

Expected Behavior

I would expect to use globalTable.replica("us-west-2") and retrieve the replica Stream ARN to as arn:aws:dynamodb:us-west-2:123456789012:table/IndraMembershipDetails-Beta/stream/<timestamp>.

Current Behavior

When getting the Stream ARN for the primary global table, CDK will create reference the exact Stream ARN i.e. arn:aws:dynamodb:us-east-1:123456789012:table/IndraMembershipDetails-Beta/stream/<timestamp>. Where as in the replica tables when using globalTable.replica("us-west-2"), it'll get the correct replica table, but the Stream ARN provided is not the exact Stream ARN, but something like this instead: arn:aws:dynamodb:us-west-2:123456789012:table/IndraMembershipDetails-Beta/stream/*.

Reproduction Steps

1. Create a Global Table configuration using TableV2
2. Configure replicas to be in two regions i.e. us-west-2 and eu-west-1
3. Get the replica in a region i.e. globalTable.replica("us-west-2")
4. Get the Stream ARN from the replica table

Possible Solution

No response

Additional Information/Context

No response

CDK CLI Version

2.87.0

Framework Version

No response

Node.js Version

v20.17.0

OS

Mac OS Sonoma 14.6.1

Language

TypeScript

Language Version

No response

Other information

No response

[khushail]

Hi @kevinhuynh23 , Thanks for reaching out.

you seem to be using very old version of CDK. Could you please try running on the latest CDK 2.156. Meanwhile I will also try to reproduce this on my end.

[kevinhuynh23]

Hi @khushail, thanks for looking to this! We are stuck on CDK 2.87.0 due to some of our dependencies. We can look into upgrading to the latest version if there's a fix for it in the later versions!

Thanks!

[kevinhuynh23]

Hi @khushail, I had sometime to work around the dependency and I tried testing the same thing on 2.155.0 and seeing the same result!

[khushail]

Hi @kevinhuynh23 , thanks for replying back with your updates.
I tried to repro the situation with the latest CDK 2.158.0. Sharing my observations -
Code snippet -

//create  a global table with replica in other regions
    const globalTable = new cdk.aws_dynamodb.TableV2(this, 'MyTable', {
      tableName: 'MyTable',
      partitionKey: { name: 'id', type: cdk.aws_dynamodb.AttributeType.STRING },
      removalPolicy: cdk.RemovalPolicy.DESTROY,
    });

    //globaltable stream arn
    new cdk.CfnOutput(this, 'GlobalTableStreamArn', {
      value: globalTable.tableStreamArn!,
    });

    //add replicas to the table
    globalTable.addReplica({ region: 'us-west-1', deletionProtection: true });

    //get the streamarn for the replicat table from region us-west-1

    new cdk.CfnOutput(this, 'ReplicaTableArn', {
      value: globalTable.replica('us-west-1').tableStreamArn!,
    });

Here is the output printed with incomplete arn -

As seen in the cdk code, this replica table is lazily created.

aws-cdk/packages/aws-cdk-lib/aws-dynamodb/lib/table-v2.ts

Line 545 in 4b8714d

replicas: Lazy.any({ produce: () => this.renderReplicaTables() }),

I am still figuring out the root cause, will share updates soon. Thanks for having patience

[khushail]

@kevinhuynh23 , here is my observation from the code which states the stream as <steam>/* -

This method adds replica in another region with the stream arn ending with *-

aws-cdk/packages/aws-cdk-lib/aws-dynamodb/lib/table-v2.ts

Line 597 in 4b8714d

const replicaStreamArn = `${replicaArn}/stream/*`;

Linked PR - e52acd8

RFC -https://github.com/aws/aws-cdk-rfcs/blob/main/text/0510-dynamodb-global-table.md
As per RFC, the reason for mentioning the stream with * as -

So It seems to be intentional the way replica arn is created.
Hope that would be helpful.
Please feel free to reach out in case of further questions. Thanks

cc: @pahud

[kevinhuynh23]

@khushail Thanks for looking into this issue!

The reason the above comment mentions an addition of a potential lookup function to determine the stream arn, are there any plans to implement this?

Also, are we not able to have the Replica Stream ARN be exported as a CloudFormation export value after the creation completes? Or does CFN have no ability to reference the value?

Thanks for the help!

[khushail]

@kevinhuynh23 , I highly doubt if the replica stream ARN could be exported as value but will definitely keep looking and share here if I find anything.

Also, I did not find any such implementation plan for the mentioned function. However you could file a feature request with CDK, and get community upvotes for getting it prioritised.

[khushail]

@kevinhuynh23 , I would be closing this issue for now.

If you need any other help/guidance, please feel free to re-open.

Thanks !

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