Locality load balancing

Istio's Locality Load Balancing (LLB) is a feature that helps distribute traffic across different geographic locations in a way that minimizes latency and maximizes availability. It routes traffic to the closest available instance of the service, reducing network hops and improving performance, while also providing fault tolerance and resilience. LLB is important for managing microservices architectures.

From the perspective of istio-nsgw: get the endpoints, priority, and weight of service-1:

# Get a running pod name
POD=$(k --context pasta-1 -n istio-system get po -l istio=nsgw --no-headers | awk 'NR==1{print $1}')

# Add an ephemeral container to the running pod
k --context pasta-1 -n istio-system debug -it \
--attach=false --image=istio/base --target=istio-proxy --container=debugger \
${POD} -- bash

# Watch for the endpoints
watch "istioctl --context pasta-1 -n istio-system pc endpoint deploy/istio-nsgw | grep -E '^END|service-1'; echo; k --context pasta-1 -n istio-system exec -it ${POD} -c debugger -- curl -X POST localhost:15000/clusters | grep '^outbound.*service-1' | grep -E 'zone|region|::priority|::weight' | sort | sed -e '/:zone:/s/$/\n/'"