4.5. Startup probes

• The service image takes a long time to pull due to its size.
• The service takes a long time to become READY because of initial cache priming.
• The cluster relies on autoscaling to allocate resources for new pods.

Procedure

• Define startup probes for your service by modifying your deployment configuration. The following example shows a configuration with two containers:

  Example of defined starup probes

  apiVersion: serving.knative.dev/v1
  kind: Service
  # ...
  spec:
    template:
      spec:
         containers:
          - name: first-container
            image: <image>
            ports:
              - containerPort: 8080
            # ...
            startupProbe: 

  1

  
            httpGet:
              port: 8080
              path: "/"
          - name: second-container
            image: <image>
            # ...
            startupProbe: 

  2

  
            httpGet:
              port: 8081
              path: "/"

  1

  Startup probe of the first-container.

  2

  Startup probe of the second-container.

• initialDelaySeconds
• failureThreshold
• periodSeconds
• timeoutSeconds

Procedure

• To configure the progress deadline setting, use an annotation in your deployment configuration.

  Example of progress deadline set to 60 seconds

  apiVersion: serving.knative.dev/v1
  kind: Service
  ...
  spec:
    template:
      metadata:
         annotations:
              serving.knative.dev/progress-deadline: "60s"
      spec:
          containers:
              - image: ghcr.io/knative/helloworld-go:latest