Describe the bug

While creating RDS MySQL instance version 8.4.3, CloudFormation failed with following error:

Resource handler returned message: "The parameter group xxxxxxxx with DBParameterGroupFamily mysql8.0 can't be used for this instance. Use a parameter group with DBParameterGroupFamily mysql8.4.

Regression Issue

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

Last Known Working CDK Version

N/A

Expected Behavior

An RDS MySQL instance version 8.4.3 is successfully created.

Current Behavior

Unable to create an RDS MySQL instance version 8.4.3.

Reproduction Steps

Deploy RDS MySQL instance with custom parameters:

new rds.Instance(this, 'MySQL84', {
  engine: rds.DatabaseInstanceEngine.mysql({ version: rds.MysqlEngineVersion.VER_8_4_3 }),
  vpc: vpc,
  instanceType: ec2.InstanceType.of(ec2.InstanceClass.BURSTABLE4_GRAVITON, ec2.InstanceSize.MICRO),
  parameters: { time_zone: 'Asia/Tokyo', require_secure_transport: '1' },
});

Possible Solution

rds.MysqlEngineVersion.VER_8_4_3 is defined as MysqlEngineVersion.of('8.4.3', '8.0') includes wrong major version.
So the parameter group with DBParameterGroupFamily mysql8.0 is being created.

Additional Information/Context

WORKAROUND: use rds.MysqlEngineVersion.of('8.4.3', '8.4') instead of rds.MysqlEngineVersion.VER_8_4_3.

CDK CLI Version

2.175.1

Framework Version

2.175.1

Node.js Version

20.18.1

OS

Ubuntu

Language

TypeScript

Language Version

No response

Other information

Related #32257