Client-side GRPC load balancing

[BojanZelic]

Proposal

Keda currently uses the pick_first load balancing policy for GRPC connections which is the grpc library default. This currently works in most setups because of default coredns configurations. However, if we're not using the default settings, Keda should perform client-side round-robin load balancing for grpc connections aswell.

Use-Case

Some Kubernetes environments customize the default DNS configurations; For example:

• disabling the loadbalance CoreDNS plugin
• and talking to a headless service

the above changes means DNS requests will always return the results in the same order and won't randomize the ordering, ex with 2 pods:

root@app-5877ff4bd9-p27mk:/# dig headless-svc.default.svc.cluster.local +short
10.1.3.215
10.1.3.210

In this case, Keda should round-robin load balance grpc connections... otherwise it's always going to talk to the same pod and not send any requests off to the second one; this is a simple 1-line config change built into the grpc library; and shouldn't affect existing setups.

Is this a feature you are interested in implementing yourself?

Yes

Anything else?

No response

[JorTurFer]

I'd say that this is already done xD