Configuring the default broker backing channel - Brokers | Eventing

If you are using a channel-based broker, you can set the default backing channel type for the broker to either InMemoryChannel or KafkaChannel.

Prerequisites

You have administrator permissions on OpenShift Container Platform.
You have installed the OpenShift Serverless Operator and Knative Eventing on your cluster.
You have installed the OpenShift (oc) CLI.
If you want to use Apache Kafka channels as the default backing channel type, you must also install the KnativeKafka CR on your cluster.

Procedure

Modify the KnativeEventing custom resource (CR) to add configuration details for the config-br-default-channel config map:

apiVersion: operator.knative.dev/v1beta1
kind: KnativeEventing
metadata:
  name: knative-eventing
  namespace: knative-eventing
spec:
  config: (1)
    config-br-default-channel:
      channel-template-spec: |
        apiVersion: messaging.knative.dev/v1beta1
        kind: KafkaChannel (2)
        spec:
          numPartitions: 6 (3)
          replicationFactor: 3 (4)

1	In `spec.config`, you can specify the config maps that you want to add modified configurations for.
2	The default backing channel type configuration. In this example, the default channel implementation for the cluster is `KafkaChannel`.
3	The number of partitions for the Kafka channel that backs the broker.
4	The replication factor for the Kafka channel that backs the broker.

Apply the updated KnativeEventing CR:
```
$ oc apply -f <filename>
```