aws-cdk: Cannot update serverless aurora maxCapacity with CfnDBCluster

If you create a serverless Aurora database with CfnDBCluster, and then try to update the maxCapacity, the deployment fails with the message: "DatabaseCluster You currently can’t modify EndpointPort with Aurora Serverless. (Service: AmazonRDS; Status Code: 400; Error Code: InvalidParameterCombination; " Even though the port was not changed.

Reproduction Steps

Create a serverless database:

  const dbCluster = new rds.CfnDBCluster(this, "DatabaseCluster", {
          engine: "aurora-postgresql",
          engineMode: "serverless",
          engineVersion: "10.7",
          masterUsername: 'postgres',
          databaseName: "collab",
          masterUserPassword: "Foobar",
          dbSubnetGroupName: new rds.CfnDBSubnetGroup(this, "CollabDbSubnetGroup", {
              dbSubnetGroupDescription: ` Collab Db cluster subnet group`,
              subnetIds: vpc.selectSubnets({subnetType: ec2.SubnetType.PRIVATE}).subnetIds
          }).ref,
          vpcSecurityGroupIds: [mySecurityGroupId],
          storageEncrypted: true,
          backupRetentionPeriod: 35,
          deletionProtection: false,
          port: 5432,
          scalingConfiguration: {
              autoPause: true,
              secondsUntilAutoPause: 300,
              minCapacity: 2,
              maxCapacity: 2
          }
      });

Deploy this.

Change nothing other than maxCapacity (to 4). Running cdk diff shows:

Stack TestCollabDbStack
Resources
[~] AWS::RDS::DBCluster DatabaseCluster DatabaseCluster
 └─ [~] ScalingConfiguration
     └─ [~] .MaxCapacity:
         ├─ [-] 2
         └─ [+] 4

Which is what you’d expect. However, if you run cdk deploy, the following happens:

TestCollabDbStack
TestCollabDbStack: deploying...
TestCollabDbStack: creating CloudFormation changeset...
 0/2 | 11:45:35 PM | UPDATE_IN_PROGRESS   | AWS::RDS::DBCluster     | DatabaseCluster
 1/2 | 11:45:36 PM | UPDATE_FAILED        | AWS::RDS::DBCluster     | DatabaseCluster You currently can't modify EndpointPort with Aurora Serverless. (Service: AmazonRDS; Status Code: 400; Error Code: InvalidParameterCombination; Request ID: 83490936-5bdf-418e-b065-7a79a176beea)

Environment

CLI Version :
Framework Version: 1.15.0
OS : Windows 10
Language : Typescript

This is 🐛 Bug Report

About this issue

Original URL
State: closed
Created 5 years ago
Reactions: 1
Comments: 18 (3 by maintainers)

Most upvoted comments

Ran into this issue as well. The solution or at least work-around, if you’re not using a custom port, is to just omit the port from the template. It’s optional and will use the default port for the engine specified and won’t be seen as a change.

vendamere on Apr 30, 2020

Had the same issue. Removing the port reference worked. I have submitted this as a bug report to AWS via our paid support account. My suggestion to both the CDK and RDS team would be to make bug reports available to all users when they can’t be escalated on the appropriate repo.

Ran into this issue as well. The solution or at least work-around, if you’re not using a custom port, is to just omit the port from the template. It’s optional and will use the default port for the engine specified and won’t be seen as a change.

chris-bateman on Jul 13, 2020

I opened a support ticket with AWS and got feedback today: According to AWS a fix was applied and this should now longer be an issue. I can confirm that at least changing CopyTagsToSnapshot and BackupRetentionPeriod via CloudFormation does not anymore result in You currently can't modify EndpointPort with Aurora Serverless ...

I can confirm that AWS support also let us know that a patch had been deployed, and we were able to get our deployment through, with an Aurora Postgres engine upgrade and no EndpointPort errors.

Thanks everyone for the quick patch and responses.

mmeylan on Oct 28, 2022

I opened a support ticket with AWS and got feedback today: According to AWS a fix was applied and this should now longer be an issue. I can confirm that at least changing CopyTagsToSnapshot and BackupRetentionPeriod via CloudFormation does not anymore result in You currently can't modify EndpointPort with Aurora Serverless ...

alex-ruehe on Oct 28, 2022

Currently experiencing this error after having updated CfnDBCluster.engineVersion (aws-cdk-lib@2.45.0). Port is not specified in the cluster construct.

How were you able to get your deployment through ?

mmeylan on Oct 26, 2022

I was having this issue as well using the CDK when simply adding a tag to the RDS Cluster. After the CfnDBCluster deployed the first time and their respective values are set I had to omit both, preferred_maintenance_window and port, for subsequent releases that modify cdk’s CfnDBCluster resource. After making the update, preferred_maintenance_window and port values persisted from the first release, my tag changes took place, and deployment was successful.

dbasargin on Jul 22, 2020

Update - AWS are aware of the issue internally - Their Response -

That being said, I have checked internally and can currently see that there is a feature request for this and our internal team is aware of it. However, I will not be able to provide an ETA as to when it would be available.

As you must already be aware, any new fix/feature requires rigorous testing and compatibility checks before rolling it out globally in order to make sure that there are no issues caused due to the same. However, please be assured that I have added a +1 on your behalf for this feature request in order to get traction on the same.

chris-bateman on Jul 13, 2020

For those of you who commented, if you have access to AWS Support, it’d be great if you file an issue with them. Unfortunately, you can’t contact AWS Support for a technical issue unless you have a paid support plan, which my company doesn’t (and currently isn’t willing to pay hundreds of dollars a month just in order to submit a bug report) – so I don’t think the RDS team even knows they have this bug.

GregThoen on Mar 5, 2020