Disable Istio default retry strategy (at least on POST requests)

Documentation

• From Istio Retries documentation: Default retry is hardcoded and it's value equal to 2.

The interval between retries (25ms+) is variable and determined automatically by Istio, preventing the called service from being overwhelmed with requests. The default retry behavior for HTTP requests is to retry twice before returning the error.

Btw, it was initially 10, but decreased to 2 in Enable retries for specific status codes and reduce num retries to 2 commit.

• workaround is to use virtual services

you can adjust your retry settings on a per-service basis in virtual services without having to touch your service code. You can also further refine your retry behavior by adding per-retry timeouts, specifying the amount of time you want to wait for each retry attempt to successfully connect to the service.

Examples

1. The following example configures a maximum of 3 retries to connect to this service subset after an initial call failure, each with a 2 second timeout.

apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: ratings
spec:
  hosts:
  - ratings
  http:
  - route:
    - destination:
        host: ratings
        subset: v1
    retries:
      attempts: 3
      perTryTimeout: 2s

2. Your case. Disabling retries. Taken from Disable globally the default retry policy:

apiVersion: networking.istio.io/v1alpha3
kind: VirtualService
metadata:
  name: no-retries-for-one-service
spec:
  hosts:
  - one-service.default.svc.cluster.local
  http:
  - retries:
      attempts: 0
    route:
      - destination:
          host: one-service.default.svc.cluster.local