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 K8sGateway waits for replies from an upstream 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 K8sGateway, set up a gateway resource, and deploy the httpbin sample app.

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

   Cloud Provider LoadBalancerPort-forward for local testing

   export INGRESS_GW_ADDRESS=$(kubectl get svc -n gloo-system gloo-proxy-http -o jsonpath="{.status.loadBalancer.ingress[0]['hostname','ip']}")
   echo $INGRESS_GW_ADDRESS  

   kubectl port-forward deployment/gloo-proxy-http -n gloo-system 8080:8080

Set up timeouts

Use a RouteOption resource to specify timeouts for a specific route.

1. Create a RouteOption custom 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.solo.io/v1
   kind: RouteOption
   metadata:
     name: timeout
     namespace: httpbin
   spec:
     options:
       timeout: '20s'
   EOF

2. Create an HTTPRoute resource for the httpbin app that references the RouteOption resource that you created.

   kubectl apply -f- <<EOF
   apiVersion: gateway.networking.k8s.io/v1beta1
   kind: HTTPRoute
   metadata:
     name: httpbin-timeout
     namespace: httpbin
   spec:
     parentRefs:
     - name: http
       namespace: gloo-system
     hostnames:
       - timeout.example
     rules:
       - filters:
           - type: ExtensionRef
             extensionRef:
               group: gateway.solo.io
               kind: RouteOption
               name: timeout
         backendRefs:
           - name: httpbin
             port: 8000
   EOF

3. Send a request to the httpbin app on the timout.example domain. Verify that the request succeeds and that you see a X-Envoy-Expected-Rq-Timeout-Ms header. If the header is present, K8sGateway expects requests to the httpbin app to succeed within the set timeout.

   LoadBalancer IP address or hostnamePort-forward for local testing

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

   curl -vik localhost:8080/headers -H "host: timeout.example"

   Example output for a successful response:

   {
    "headers": {
      "Accept": [
        "*/*"
      ],
      "Host": [
        "timeout.example: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"
      ]
    }
   }
   

4. Optional: Remove the resources that you created.

   kubectl delete httproute httpbin-timeout -n httpbin
   kubectl delete routeoption timeout -n httpbin