05/30/2023, 7:19 AM
Hello everyone, I tried to create a app scaling policy for RDS cluster but I’m getting the below error message. I confirmed with AWS doc that all the given params are correct and supported but still i’m facing this issue.
creating Application AutoScaling Target: ValidationException: Unsupported service namespace, resource type or scalable dimension
Did anyone face this kinda issue or any idea on this? Please help me with this. Thanks The script is here,
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// RDS Auto Scaling Policy based on Memory Utilization
export function appMemoryScalingPolicy(rdsCpuScalingArgs: any) {
    const {
      minCapacity = 1,
      maxCapacity = 2,
      targetValue = 70,
      scaleInCooldown = 300,
      scaleOutCooldown = 300,
      disableScaleIn = false,
    } = rdsCpuScalingArgs;
    const scalingTarget = new aws.appautoscaling.Target("rdsCpuScalingTarget", {
      serviceNamespace: "rds",
      scalableDimension: "rds:cluster:ReadReplicaCount",
      resourceId: `cluster:${clusterId}`,
      minCapacity: minCapacity,
      maxCapacity: maxCapacity,
    return new aws.appautoscaling.Policy("rdsCpuScalingPolicy", {
      serviceNamespace: scalingTarget.serviceNamespace,
      scalableDimension: scalingTarget.scalableDimension,
      resourceId: scalingTarget.resourceId,
      policyType: "TargetTrackingScaling",
      targetTrackingScalingPolicyConfiguration: {
        customizedMetricSpecification: {
          metricName: "FreeableMemory",
          namespace: "AWS/RDS",
          statistic: "Average",
          unit: "Bytes"
        targetValue: targetValue,
        scaleInCooldown: scaleInCooldown,
        scaleOutCooldown: scaleOutCooldown,
        disableScaleIn: disableScaleIn,


05/30/2023, 9:48 AM
I haven’t used autoscaling with RDS, but the syntax looks ok to me—it matches an ECS autoscaling target in my codebase I can see that the doco explicitly says it’s supported for Aurora for MySQL and Aurora for Postgres:[…]equest-ScalableDimension I don’t suppose you’re trying to use a database engine? Or possibly a non-Aurora (plain RDS) cluster?


05/30/2023, 9:52 AM
I actually tried for both aurora and non aurora postgresql clusters and I got the same error for both.
Also, I did try for ECS Scaling as well with the same
appscaling target
and that also didn’t work.. same error there 😐 I’m suspecting whether this is a bug or something. Am I the only one who face this kinda error ?🤔
Still struggling with this issue. The experts help or ideas are much appreciated here. Thanks