Configure Controller Policies

This doc shows you how to configure a basic controller policy that manages an application. There are many policy knobs not covered by this document. To see a full specification of everything you can configure, check out the Controller Policies reference.

Prerequisites

Make sure you have the following environment variables set.

Environment Variable	Description
APPLICATION_NAME	The k8s name of your application's Deployment or StatefulSet
APPLICATION_NAMESPACE	The k8s namespace your application is deployed into.
APPLICATION_ID	The id of your application in Responsive Cloud.

Defining and Deploying A Policy

You specify a policy as a k8s Custom Resource. To define an example policy that tries to ensure your application's processing latency is kept under 1 minute, run:

echo "apiVersion: \"application.responsive.dev/v1\"
kind: \"ResponsivePolicy\"
metadata:
  name: ${APPLICATION_NAME}
  namespace: ${APPLICATION_NAMESPACE}
spec:
  applicationNamespace: ${APPLICATION_NAMESPACE}
  applicationName: ${APPLICATION_NAME}
  applicationId: ${APPLICATION_ID}
  status: POLICY_STATUS_MANAGED
  policyType: KAFKA_STREAMS
  kafkaStreamsPolicy:
    maxReplicas: 3
    diagnosers:
      - type: EXPECTED_LATENCY
        expectedLatency:
          maxExpectedLatencySeconds: 60
          scaleUpStrategy:
             type: RATE_BASED
      - type: THREAD_SATURATION
        threadSaturation:
          threshold: .65
" >> policy.yaml

Then, to apply the policy:

kubectl apply -f policy.yaml