How can I configure traffic balancing for a service using Istio?

We use a headless service to balance traffic, but progers do not like this option. Installed istio, I read the documentation, but my eyes run wide.

Now the task is: Balance traffic to the service, in my case: results-service2.predprod.svc.cluster.local

Do I understand correctly that it is enough for me to create a DestinationRule and all incoming traffic to results-service2.predprod.svc.cluster.local will be balanced on replicas using the LEAST_CONN balancing algorithm?

In my case:

apiVersion: networking.istio.io/v1alpha3
kind: DestinationRule
metadata:
  name: results-load-balancer
spec:
  host: results-service2.predprod.svc.cluster.local
  trafficPolicy:
      loadBalancer:
        simple: LEAST_CONN

Solution

Istio destination rule is place to define service load balancing algorithm. By default istio uses "LEAST_REQUEST" as LB algorithm. "LEAST_CONN" is deprecated algorithm. More details are mentioned in istio documentation. If you would like to change LB algorithm to "ROUND_ROBIN" or another supported methon this can be done as per below sample

apiVersion: networking.istio.io/v1alpha3
kind: DestinationRule
metadata:
  name: configure-client-mtls-dr-with-workloadselector
spec:
  host: example.com
  workloadSelector:
    matchLabels:
      app: ratings
  trafficPolicy:
    loadBalancer:
      simple: ROUND_ROBIN