Autoscaling Deployments with Cloud Monitoring metrics - kubernetes

Question

I am trying to auto-scale my pods based on CloudSQL instance response time. We are using cloudsql-proxy for secure connection.
Deployed the Custom Metrics Adapter.
https://raw.githubusercontent.com/GoogleCloudPlatform/k8s-stackdriver/master/custom-metrics-stackdriver-adapter/deploy/production/adapter_new_resource_model.yaml
apiVersion: autoscaling/v2beta2
kind: HorizontalPodAutoscaler
metadata:
name: application_name
spec:
minReplicas: 1
maxReplicas: 5
scaleTargetRef:
apiVersion: apps/v1
kind: Deployment
name: application_name
minReplicas: 1
maxReplicas: 5
metrics:
- type: Pods
pods:
metric:
name: custom-metric-stackdriver-adapter
target:
type: AverageValue
averageValue: 20
I deployed the application and create HPA for that, But i am seeing error.
AbleToScale True SucceededGetScale the HPA controller was able to get the target's current scale
ScalingActive False FailedGetPodsMetric the HPA was unable to compute the replica count: unable to get metric custom-metric: unable to fetch metrics from custom metrics API: the server could not find the descriptor for metric custom.googleapis.com/custom-metric: googleapi: Error 404: Could not find descriptor for metric 'custom.googleapis.com/custom-metric'., notFound
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Warning FailedGetPodsMetric 4m22s (x10852 over 47h) horizontal-pod-autoscaler unable to get metric custom-metric: unable to fetch metrics from custom metrics API: the server could not find the descriptor for metric custom.googleapis.com/custom-metric: googleapi: Error 404: Could not find descriptor for metric 'custom.googleapis.com/custom-metric'., notFound

Answer 1

Please refer to the link below to deploy a HorizontalPodAutoscaler (HPA) resource to scale your application based on Cloud Monitoring metrics.
https://cloud.google.com/kubernetes-engine/docs/tutorials/autoscaling-metrics#custom-metric_4
Looks like the custom metric name is different in the app and hpa deployment configuration files(yaml). Metric and application names should be the same in both app and hpa deployment configuration files.
In the hpa deployment yaml file,
a. Replace custom-metric-stackdriver-adapter with custom-metric (Or change the
metric name to custom-metric-stackdriver-adapter in the app deployment yaml
file).
b. Add “namespace: default” next to the application name at metadata.Also
ensure you are adding the namespace in the app deployment configuration
file.
c. Delete the duplicate lines 6 & 7 (minReplicas: 1, maxReplicas: 5).
d. Go to Cloud Console->Kubernetes Engine->Workloads. Delete the workloads (application-name & custom-metrics-stackdriver-adapter) created by app deployment yaml and adapter_new_resource_model.yaml files.
e. Now apply configurations to resource model, app and hpa (yaml files).