Knative Kafka Broker Partitioning Defaults to 0, Ignoring CloudEvents Extension

[iampratapak]

We are using Knative Eventing with a Kafka Broker. Below is our kafka-broker-config configMap and the Broker.

kafka-broker-config:

apiVersion: v1
data:
  bootstrap.servers: fabric-kafka-bootstrap.kafka:9092
  default.topic.partitions: "100"
  default.topic.replication.factor: "1"
kind: ConfigMap
metadata:
  labels:
    app.kubernetes.io/version: 9e97bb4546340598bf40be83c8ffa9deaee5eb46
  name: kafka-broker-config
  namespace: knative-eventing

Broker:

apiVersion: eventing.knative.dev/v1
kind: Broker
metadata:
  annotations:
    eventing.knative.dev/broker.class: Kafka
    eventing.knative.dev/creator: system:serviceaccount:dx-system:fabric-operator
    eventing.knative.dev/lastModifier: system:serviceaccount:dx-system:fabric-operator
  finalizers:
  - brokers.eventing.knative.dev
  generation: 1
  labels:
    dx4c.managed: "true"
    eventing.knative.dev/broker.class: Kafka
  name: default
  namespace: dx-prod
spec:
  config:
    apiVersion: v1
    kind: ConfigMap
    name: kafka-broker-config
    namespace: knative-eventing
  delivery:
    backoffDelay: PT15S
    backoffPolicy: linear
    retry: 5760

I am sending two events, and both are going to the same partition (Partition 0). In fact, all the events I send are going to a single partition.

Event1:

curl -X POST -v \
-H "content-type: application/json"  \
-H "ce-specversion: 1.0"  \
-H "ce-source: your/curl/command"  \
-H "ce-type: event_type_1"  \
-H "ce-id: 0915"  \
-H "ce-partitionkey: key1"  \
-d '{"value":"Hello Knative", "partitionkey": "key1"}' \
http://kafka-broker-ingress.knative-eventing.svc.cluster.local/dx-prod/default

Event2:

curl -X POST -v \
-H "content-type: application/json"  \
-H "ce-specversion: 1.0"  \
-H "ce-source: my/curl/command"  \
-H "ce-type: event_type_2"  \
-H "ce-id: 0916"  \
-H "ce-partitionkey: key2"  \
-d '{"value":"Hello Knative", "partitionkey": "key2"}' \
http://kafka-broker-ingress.knative-eventing.svc.cluster.local/dx-prod/default

My questions are:

1. Is the value of the partitionkey not being honored when selecting the partition?
2. How do I correctly set the partition key for the Kafka Broker?

[iampratapak]

My apologies, we had only one partition for the topic "knative-broker-dx-prod-default". After manually increasing the partition count for this topic, different messages with different partitionkey values are now successfully going to different partitions.