Circuit breaker doesn't trip on httpConsecutiveErrors: 1 (for 500 response). All requests pass through and give a 500 instead . Circuit breaker should trip and should return 503(Service Unavailable) instead .

Follow the steps Circuit breaker setup .

Once httpbin is up you can simulate 500 with it Request :

kubectl exec -it $FORTIO_POD -c fortio /usr/local/bin/fortio -- load -c 1 -qps 0 -n 20 -loglevel Warning http://httpbin:8000/status/500

Running this will simulate 20 requests returning 500 .

But if you have applied the circuit breaker if should allow just the one request as 500 and remaining requests should be tripped and a 503 should be returned . This doesn't happen. Issue raised on github Github issue