VirtualServiceIneffectiveMatch

This message occurs when a virtual service contains a match rule that will never be used because a previous rule specifies the same match.

Example

You will receive this message:

Info [IST0131] (VirtualService tls-routing.default) VirtualService rule #1 match #0 is not used (duplicates a match in rule #0).

when your cluster has the following virtual service:

apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: tls-routing
spec:
  hosts:
  - www1.googleapis.com
  - api1.facebook.com
  tls:
  - match:
    - port: 2443
      sniHosts:
      - www1.googleapis.com
    route:
    - destination:
        host: www1.googleapis.com
  - match:
    - port: 2443
      sniHosts:
      - www1.googleapis.com
    route:
    - destination:
        host: api1.facebook.com

In this example, the virtual service specifies two different destinations for the same match. Istio will use the first match, and never send traffic to the second destination.

How to resolve

If you need traffic to go to more than one place, use mirror.

Re-order your routes so that the most specific ones are first. Place ‘catch all’ routes at the end.