Metrics not using trigger name in AWS CloudWatch scaler

[steveratay]

I have defined a scaler based on AWS CloudWatch which includes multiple triggers, each for a separate metric in CloudWatch. They are defined as follows, using the name field which is documented as a trigger field here: https://keda.sh/docs/2.11/concepts/scaling-deployments/#triggers

  triggers:
  - type: aws-cloudwatch
    name: custom-name-1
    metadata:
      # details here are irrelevant and therefore excluded
  - type: aws-cloudwatch
    name: custom-name-2
    metadata:
      # details here are irrelevant and therefore excluded

However, when the HPA is created it looks like this, with a generic metric name, and I can't easily discern one metric from the other:

Metrics:                                       ( current / target )
  "s0-aws-cloudwatch" (target average value):  0 / 10k
  "s1-aws-cloudwatch" (target average value):  0 / 10k

This seems like a bug to me but it's clearly coded this was at

keda/pkg/scalers/aws_cloudwatch_scaler.go

Line 297 in 89fb01a

Name: GenerateMetricNameWithIndex(s.metadata.scalerIndex, "aws-cloudwatch"),

. Looking through some of the other scalers I see a mix of some using the metric name and others not. Can anyone explain why this is the case? Shouldn't the scaler be using the name field if it's defined and only falling back to this generic naming scheme if there is no name defined?

Not sure if I should open this as a bug or not, so I figured I would start here. Thanks!

[JorTurFer]

Hello,
The metric name in the HPA is part of KEDA internals. You can use the property name in trigger spec to provide an arbitrary name that will be added as label on exposed prometheus metrics. This decision came from the problems related with custom naming constraints (ASCII chars, length, etc).

The HPA is something internal that KEDA uses for providing the functionality and we decided to not extend the support for custom names as part of HPA any more to make the things easier, taking into account that KEDA already exposes metrics with that info