Difficulty Specifying Target Group Dimension for AWS CloudWatch in KEDA 2.13.0

[Ravikapadne]

Hi Team,

I am encountering an issue with KEDA version 2.13.0 where I can successfully specify a dimension for a Load Balancer in an AWS CloudWatch trigger, but face difficulties when trying to specify a dimension for a Target Group. My goal is to scale based on the RequestCount metric, considering both the Load Balancer and Target Group dimensions.

Here's the part of my manifest related to the AWS CloudWatch trigger:

apiVersion: [keda.sh/v1alpha1](http://keda.sh/v1alpha1)
kind: ScaledObject
metadata:
  name: pscoreqa-scaledobject
  namespace: default
spec:
  scaleTargetRef:
    name: pscoreqa
  minReplicaCount: 1
  maxReplicaCount: 5
  triggers:
    - type: aws-cloudwatch
      metadata:
        namespace: AWS/ApplicationELB
        metricName: RequestCount
        dimensionName: TargetGroup
        dimensionValue: "targetgroup/525833f1-53f9b0a54939af1c7c2/1c0fbedd5a195a27"
        dimensionName: LoadBalancer
        dimensionValue: "app/525833f1-default-psqaexter-680d/49ebe907a9a9176f"
        targetMetricValue: "100"
        minMetricValue: "50"
        metricStatPeriod: "60"
        metricStat: "Sum"
        awsRegion: "ap-south-1"
        identityOwner: operator

When applying this configuration, it seems that only the dimension for the Load Balancer is recognized and utilized by KEDA for scaling decisions

Also, i have tried the apply manifest for target group and its showing below logs in the keda operator logs.

Manifest:

apiVersion: keda.sh/v1alpha1
kind: ScaledObject
metadata:
  name: pscoreqa-scaledobject
  namespace: default
spec:
  scaleTargetRef:
    name: pscoreqa
  minReplicaCount: 1
  maxReplicaCount: 5
  triggers:
    - type: aws-cloudwatch
      metadata:
        namespace: AWS/ApplicationELB
        metricName: RequestCount
        dimensionName: TargetGroup
        dimensionValue: "targetgroup/525833f1-53f9b0a54939af1c7c2/1c0fbedd5a195a27"
        targetMetricValue: "100"
        minMetricValue: "50"
        metricStatPeriod: "60"
        metricStat: "Sum"
        awsRegion: "ap-south-1"
        identityOwner: operator

2024-03-04T13:40:30Z	DEBUG	aws_cloudwatch_scaler	Received Metric Data	{"type": "ScaledObject", "namespace": "default", "name": "pscoreqa-scaledobject", "data": {"Messages":[],"MetricDataResults":[{"Id":"c1","Label":"RequestCount","Messages":null,"StatusCode":"Complete","Timestamps":[],"Values":[]}],"NextToken":null,"ResultMetadata":{}}}
2024-03-04T13:40:30Z	INFO	aws_cloudwatch_scaler	empty metric data received, returning minMetricValue	{"type": "ScaledObject", "namespace": "default", "name": "pscoreqa-scaledobject"}
2024-03-04T13:40:30Z	DEBUG	scale_handler	Getting metrics from trigger	{"scaledObject.Namespace": "default", "scaledObject.Name": "pscoreqa-scaledobject", "trigger": "awsCloudwatchScaler", "metricName": "s0-aws-cloudwatch", "metrics": [{"metricName":"s0-aws-cloudwatch","metricLabels":null,"timestamp":"2024-03-04T13:40:30Z","value":"50"}], "scalerError": null}
2024-03-04T13:40:30Z	DEBUG	grpc_server	Providing metrics	{"scaledObjectName": "pscoreqa-scaledobject", "scaledObjectNamespace": "default", "metrics": "&ExternalMetricValueList{ListMeta:{   <nil>},Items:[]ExternalMetricValue{ExternalMetricValue{MetricName:s0-aws-cloudwatch,MetricLabels:map[string]string{},Timestamp:2024-03-04 13:40:30.486163159 +0000 UTC m=+736.513472403,WindowSeconds:nil,Value:{{50000 -3} {<nil>}  DecimalSI},},},}"}

EKS Version: 1.27.7
KEDA Version: 2.13.0