[draft]

Title: Configuraing BURST and QPS for net-kourier

New section: https://docs.openshift.com/serverless/1.28/knative-serving/

The number of client requests or API calls that are sent to the API server is determined by the queries per second (QPS) value. The number of requests the client can make in excess of the QPS rate depends on the burst value, this is helpful for controller that are bursty in nature and can make irregular number of requests.

When the net-kourier-controller restarts, it parses all ingress resources deployed on the cluster, which leads to a significant number of API calls being executed. Consequently, it takes a considerable amount of time for net-kourier-controller to complete the start process.

The KnativeServing CR allows for the adjustment of QPS (Queries Per Second) and burst values in the serverless environment:

apiVersion: operator.knative.dev/v1beta1
kind: KnativeServing
metadata:
  name: knative-serving
  namespace: knative-serving
spec:
  workloads:
  - name: net-kourier-controller
    env:
    - container: controller
      envVars:
      - name: KUBE_API_BURST
        value: "200"   <1>
      - name: KUBE_API_QPS
        value: "200"   <2>

<1> .. The QPS rate at which the controller talks to the APIServer. The default is 200.
<2> .. The burst rate at which the Kubelet talks to the APIServer. The default is 200.