Prometheus

Kubernetes cluster monitors are in a DOWN state

When viewing targets in the Prometheus console, some Kubernetes cluster monitors may be down (kube-etcd, kube-proxy, and such). This is likely caused by the configuration of the Kubernetes cluster itself. Depending on the type of cluster, certain metrics may be disabled by default. Enabling metrics is cluster dependent; for details, refer to the documentation for your cluster type.

For example, to enable kube-proxy metrics on Kind clusters, edit the kube-proxy ConfigMap.

$ kubectl edit cm/kube-proxy -n kube-system

Replace the metricsBindAddress value with the following and save the ConfigMap.

metricsBindAddress: 0.0.0.0:10249

Then, restart the kube-proxy pods.

$ kubectl delete pod -l k8s-app=kube-proxy -n kube-system

For more information, see this GitHub issue.

Metrics Trait Service Monitor not discovered

Metrics Traits use Service Monitors which require a Service to collect metrics. If your OAM workload is created with a Metrics Trait and no Ingress Trait, a Service might not be generated for your workload and will need to be created manually.

This troubleshooting example uses the hello-helidon application.

Verify a Service Monitor exists for your application workload.

$ kubectl get servicemonitors -n hello-helidon

Verify a Service exists for your application workload.

$ kubectl get services -n hello-helidon

If no Service exists, create one manually. This example uses the default Prometheus port.

apiVersion: v1
kind: Service
metadata:
  name: hello-helidon-service
  namespace: hello-helidon
spec:
  selector:
    app: hello-helidon
  ports:
    - name: tcp-hello-helidon
      port: 8080
      protocol: TCP
      targetPort: 8080

After you’ve completed these steps, you can verify metrics collection has succeeded.