Documentation
Resiliency
Timeouts

Timeouts

Set a maximum time for the gateway to handle a request, including error retries.

About

A timeout is the amount of time (duration) that kgateway waits for replies from a backend service before the service is considered unavailable. This setting can be useful to avoid your apps from hanging or fail if no response is returned in a specific timeframe. With timeouts, calls either succeed or fail within a predicatble timeframe.

The time an app needs to process a request can vary a lot which is why applying the same timeout across services can cause a variety of issues. For example, a timeout that is too long can result in excessive latency from waiting for replies from failing services. On the other hand, a timeout that is too short can result in calls failing unnecessarily while waiting for an operation that needs responses from multiple services.

Before you begin

  1. Follow the Get started guide to install kgateway.

  2. Follow the Sample app guide to create an API gateway proxy with an HTTP listener and deploy the httpbin sample app.

  3. Get the external address of the gateway and save it in an environment variable. 

    export INGRESS_GW_ADDRESS=$(kubectl get svc -n kgateway-system http -o jsonpath="{.status.loadBalancer.ingress[0]['hostname','ip']}")
echo $INGRESS_GW_ADDRESS  
    kubectl port-forward deployment/http -n kgateway-system 8080:8080

Set up timeouts

Specify timeouts for a specific route.

  1. Create an HTTPRoute resource to specify your timeout rules. In the following example, the request must be completed within 20 seconds.

    kubectl apply -n httpbin -f- <<EOF
apiVersion: gateway.networking.k8s.io/v1
kind: HTTPRoute
metadata:
  name: httpbin-timeout
spec:
  hostnames:
  - timeout.example
  parentRefs:
  - group: gateway.networking.k8s.io
    kind: Gateway
    name: http
    namespace: kgateway-system
  rules:
  - matches: 
    - path:
        type: PathPrefix
        value: /
    backendRefs:
    - group: ""
      kind: Service
      name: httpbin
      port: 8000
    timeouts:
      request: "20s"
EOF

  2. Send a request to the httpbin app. Verify that the request succeeds and that you see a X-Envoy-Expected-Rq-Timeout-Ms header. If the header is present, kgateway expects requests to the httpbin app to succeed within the set timeout. 

    curl -vi http://$INGRESS_GW_ADDRESS:8080/headers -H "host: timeout.example:8080"
    curl -vi localhost:8080/headers -H "host: timeout.example"

    Example output for a successful response:

    {
 "headers": {
   "Accept": [
     "*/*"
   ],
   "Host": [
     "www.example.com:8080"
   ],
   "User-Agent": [
     "curl/7.77.0"
   ],
   "X-Envoy-Expected-Rq-Timeout-Ms": [
     "20000"
   ],
   "X-Forwarded-Proto": [
     "http"
   ],
   "X-Request-Id": [
     "0ae53bc3-2644-44f2-8603-158d2ccf9f78"
   ]
 }
}

  3. Optional: Remove the HTTPRoute that you created.

    kubectl delete httproute httpbin-timeout -n httpbin
Mirroring