I've created a Kubernetes Service whose backend nodes aren't part of the Cluster but a fixed set of nodes (having fixed IPs), so I've also created an Endpoints resource with the same name:

apiVersion: v1
kind: Service
metadata:
  name: elk-svc
spec:
  ports:
    - port: 9200
      targetPort: 9200
      protocol: TCP
---
kind: Endpoints
apiVersion: v1
metadata:
  name: elk-svc
subsets:
  -
    addresses:
      - { ip: 172.21.0.40 }
      - { ip: 172.21.0.41 }
      - { ip: 172.21.0.42 }

    ports:
      - port: 9200

Description of Service and Endpoints:

$ kubectl describe svc elk-svc
Name:           elk-svc
Namespace:      default
Labels:         <none>
Annotations:        kubectl.kubernetes.io/last-applied-configuration={"apiVersion":"v1","kind":"Service","metadata":{"annotations":{},"name":"elk-svc","namespace":"default"},"spec":{"ports":[{"port":9200,"protocol":"TCP"...
Selector:       <none>
Type:           ClusterIP
IP:         10.233.17.18
Port:           <unset> 9200/TCP
Endpoints:      172.21.0.40:9200,172.21.0.41:9200,172.21.0.42:9200
Session Affinity:   None
Events:         <none>

$ kubectl describe ep elk-svc
Name:       elk-svc
Namespace:  default
Labels:     <none>
Annotations:    kubectl.kubernetes.io/last-applied-configuration={"apiVersion":"v1","kind":"Endpoints","metadata":{"annotations":{},"name":"elk-svc","namespace":"default"},"subsets":[{"addresses":[{"ip":"172.21.0.40"...
Subsets:
  Addresses:        172.21.0.40,172.21.0.41,172.21.0.42
  NotReadyAddresses:    <none>
  Ports:
    Name    Port    Protocol
    ----    ----    --------
    <unset> 9200    TCP

Events: <none>

My pods are able to communicate with ElasticSearch using the internal cluster IP 10.233.17.18. Everything goes fine !

My question is about if there's any way to have some kind of healthCheck mechanism for that Service I've created so if one of my ElasticSearch nodes goes down, ie: 172.21.0.40, then the Service is aware of that and and will no longer route traffic to that node, but to the others. Is that possible ?

Thanks.