Metrics¶

The metric configuration defines which metric type is watched by the Autoscaler.

Setting metrics per revision¶

For per-revision configuration, this is determined using the autoscaling.knative.dev/metric annotation. The possible metric types that can be configured per revision depend on the type of Autoscaler implementation you are using:

The default KPA Autoscaler supports the concurrency and rps metrics.
The HPA Autoscaler supports the cpu metric.

For more information about KPA and HPA, see the documentation on Supported Autoscaler types.

Per-revision annotation key: autoscaling.knative.dev/metric
Possible values: "concurrency", "rps", "cpu", "memory" or any custom metric name, depending on your Autoscaler type. The "cpu", "memory", and custom metrics are supported on revisions that use the HPA class.
Default: "concurrency"

ConcurrencyRequests per secondCPUMemoryCustom metric

apiVersion: serving.knative.dev/v1
kind: Service
metadata:
  name: helloworld-go
  namespace: default
spec:
  template:
    metadata:
      annotations:
        autoscaling.knative.dev/metric: "concurrency"
        autoscaling.knative.dev/target-utilization-percentage: "70"

Note

The autoscaling.knative.dev/target-utilization-percentage annotation for "Concurrency" specifies a percentage value. See Configuring targets for more details.

apiVersion: serving.knative.dev/v1
kind: Service
metadata:
  name: helloworld-go
  namespace: default
spec:
  template:
    metadata:
      annotations:
        autoscaling.knative.dev/metric: "rps"
        autoscaling.knative.dev/target: "150"

Note

The autoscaling.knative.dev/target annotation for "Requests per second" specifies an integer value. See Configuring targets for more details.

apiVersion: serving.knative.dev/v1
kind: Service
metadata:
  name: helloworld-go
  namespace: default
spec:
  template:
    metadata:
      annotations:
        autoscaling.knative.dev/class: "hpa.autoscaling.knative.dev"
        autoscaling.knative.dev/metric: "cpu"
        autoscaling.knative.dev/target: "100"

Note

The autoscaling.knative.dev/target annotation for "CPU" specifies the integer value in millicore. See Configuring targets for more details.

apiVersion: serving.knative.dev/v1
kind: Service
metadata:
  name: helloworld-go
  namespace: default
spec:
  template:
    metadata:
      annotations:
        autoscaling.knative.dev/class: "hpa.autoscaling.knative.dev"
        autoscaling.knative.dev/metric: "memory"
        autoscaling.knative.dev/target: "75"

Note

The autoscaling.knative.dev/target annotation for "Memory" specifies the integer value in Mi. See Configuring targets for more details.

You can create an HPA to scale the revision by a metric that you specify. The HPA will be configured to use the average value of your metric over all the Pods of the revision.

apiVersion: serving.knative.dev/v1
kind: Service
metadata:
  name: helloworld-go
  namespace: default
spec:
  template:
    metadata:
      annotations:
        autoscaling.knative.dev/class: "hpa.autoscaling.knative.dev"
        autoscaling.knative.dev/metric: "<metric-name>"
        autoscaling.knative.dev/target: "<target>"

Where <metric-name> is your custom metric.

Next steps¶

Configure concurrency targets for applications
Configure requests per second targets for replicas of an application