Istio stop loadbalancing when add configs for outlier detections

Networking
1

Team ,

I’ve been playing around with isito1.7 and outlier detections, here are some weird things I found
vs-dr.yaml
apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
name: recommendation
spec:
hosts:
- “recommendation-demo.com”
gateways:
- istio-system/monitoring-gateway
http:

  • name: “other-account-route”
    route:
    • destination:
      host: recommendation
      subset: v2
      weight: 100
    • destination:
      host: recommendation
      subset: v1
      weight: 0

apiVersion: networking.istio.io/v1alpha3
kind: DestinationRule
metadata:
name: recomm-dr
spec:
host: recommendation
subsets:

  • name: v2
    labels:
    version: v2
    trafficPolicy:
    loadBalancer:
    simple: ROUND_ROBIN
    connectionPool:
    tcp: {}
    http: {}
    outlierDetection:
    consecutiveErrors: 2
    interval: 1s
    baseEjectionTime: 30s
    maxEjectionPercent: 10
  • name: v1
    labels:
    version: v1

so If outlier detection is not configured in destination rules , the loadbalacing is working successfully like

kubectl -n micro exec -it $CLIENT_POD -c istio-proxy – sh -c ‘while true; do curl -L recommendation-demo.com; sleep 1; done’
recommendation v2 from ‘recommendation-v2-57ddf9cd95-wb7rj’: 45
recommendation v2 from ‘recommendation-v2-57ddf9cd95-skkgd’: 851
recommendation v2 from ‘recommendation-v2-57ddf9cd95-jtkrz’: 44
recommendation v2 from ‘recommendation-v2-57ddf9cd95-wb7rj’: 46
recommendation v2 from ‘recommendation-v2-57ddf9cd95-skkgd’: 852
recommendation v2 from ‘recommendation-v2-57ddf9cd95-jtkrz’: 45
recommendation v2 from ‘recommendation-v2-57ddf9cd95-wb7rj’: 47
recommendation v2 from ‘recommendation-v2-57ddf9cd95-skkgd’: 853
recommendation v2 from ‘recommendation-v2-57ddf9cd95-jtkrz’: 46
recommendation v2 from ‘recommendation-v2-57ddf9cd95-wb7rj’: 48
recommendation v2 from ‘recommendation-v2-57ddf9cd95-jtkrz’: 47
recommendation v2 from ‘recommendation-v2-57ddf9cd95-skkgd’: 854

But after I add this part
outlierDetection:
consecutiveErrors: 2
interval: 1s
baseEjectionTime: 30s
maxEjectionPercent: 10
the only result I got is from
recommendation v2 from ‘recommendation-v2-57ddf9cd95-skkgd’: 1321
recommendation v2 from ‘recommendation-v2-57ddf9cd95-skkgd’: 1322
recommendation v2 from ‘recommendation-v2-57ddf9cd95-skkgd’: 1323
recommendation v2 from ‘recommendation-v2-57ddf9cd95-skkgd’: 1324
recommendation v2 from ‘recommendation-v2-57ddf9cd95-skkgd’: 1325
recommendation v2 from ‘recommendation-v2-57ddf9cd95-skkgd’: 1326
recommendation v2 from ‘recommendation-v2-57ddf9cd95-skkgd’: 1327
And BTW after I add the outlier config and then scale out the deployment , the youngest pod can be routed successfully
recommendation v2 from ‘recommendation-v2-57ddf9cd95-xhq4n’: 32
recommendation v2 from ‘recommendation-v2-57ddf9cd95-xhq4n’: 33
recommendation v2 from ‘recommendation-v2-57ddf9cd95-skkgd’: 1364
recommendation v2 from ‘recommendation-v2-57ddf9cd95-xhq4n’: 34
recommendation v2 from ‘recommendation-v2-57ddf9cd95-skkgd’: 1365
recommendation v2 from ‘recommendation-v2-57ddf9cd95-xhq4n’: 35
recommendation v2 from ‘recommendation-v2-57ddf9cd95-skkgd’: 1366
recommendation v2 from ‘recommendation-v2-57ddf9cd95-xhq4n’: 36
So my question is ,

  1. Is this an expected behaviour ? In this case, lets say we have 3 pods in one rs ,and apply the ourlier configs then the request will only routed to the youngest pod recommendation-v2-57ddf9cd95-skkgd
  2. We have rs and outlier configs in place , then we add extra pods to the rs , they can be loadbalanced successfully ?
  3. Anyone has sucess configs for outliers ?

Much appreciated for any replies!