Istio fallback config for SNI based routing

1

We use Istio for deployment of our services and have configured TLS SNI based routing rules. Here’s a snippet of our .yaml file :

spec:
  gateways:
  - istio-system/istio-ingressgateway
  hosts:
  - service.com
  - deployment0.com
  - deployment1.com
  tls:
  - match:
    - port: 8443
      sniHosts:
      - service.com
    route:
    - destination:
        host: service.local
        port:
          number: 8443
  - match:
    - port: 8443
      sniHosts:
      - deployment0.com
    route:
    - destination:
        host: deployment-0.local
        port:
          number: 8443
  - match:
    - port: 8443
      sniHosts:
      - deployment1.com
    route:
    - destination:
        host: deployment-1.local
        port:
          number: 8443

Here, deployment-0.local, deployment-1.local refer to K8s stateful pods and service.local to the K8s service front-ending the pods

So, when a request from a client carries SNI (in ClientHello packet) as deployment0.com, it gets routed by Istio to the stateful pod deployment-0.local. However, if that pod is down at this moment, Istio seems to send a HTTP 503 response code to the client.

Instead of HTTP 503 being sent, is there a way to enforce Istio to send the request to any other available pod, if the pod, it is supposed to send the request to, is down ?

TIA !