I am unable to get circuit breaking configuration to work on my elb through egress config.

ELB elb has success rate of 25% (75% 500 error & 25% with status 200), the elb has 4 instances, only 1 returns a successful response, other instances are configured to returns 500 error for testing purpose.

Setup

• k8s: v1.7.4

• istio: 0.5.0

• env: k8s on aws

Egress rule

apiVersion: config.istio.io/v1alpha2
kind: EgressRule
metadata:
  name: elb-egress-rule
spec:
  destination:
    service: xxxx.us-east-1.elb.amazonaws.com
  ports:
    - port: 80
      protocol: http

Destination Policy

kind: DestinationPolicy
metadata:
  name: elb-circuit-breaker
spec:
  destination:
    service: xxxx.us-east-1.elb.amazonaws.com
  loadBalancing:
    name: RANDOM
  circuitBreaker:
    simpleCb:
      maxConnections: 100
      httpMaxPendingRequests: 100
      sleepWindow: 3m
      httpDetectionInterval: 1s
      httpMaxEjectionPercent: 100
      httpConsecutiveErrors: 3
      httpMaxRequestsPerConnection: 10

Route rules: not set

Testing

apiVersion: v1
kind: Service
metadata:
  name: sleep
  labels:
    app: sleep
spec:
  ports:
  - port: 80
    name: http
  selector:
    app: sleep
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: sleep
spec:
  replicas: 1
  template:
    metadata:
      labels:
        app: sleep
    spec:
      containers:
      - name: sleep
        image: tutum/curl
        command: ["/bin/sleep","infinity"]
        imagePullPolicy: IfNotPresent

.

export SOURCE_POD=$(kubectl get pod -l app=sleep -o jsonpath={.items..metadata.name})
    kubectl exec -it $SOURCE_POD -c sleep bash

Sending requests in parallel from the pod

#!/bin/sh
set -m # Enable Job Control
for i in `seq 100`; do # start 100 jobs in parallel
  curl xxxx.us-east-1.elb.amazonaws.com &
done

Response