GroupID

[GrSof]

Hello,

I'm using NiFi to establish a flow between Kafka and another system. The KafkaConsumer processor in NiFi has a mandatory value called: groupId. My cluster configuration is the following:

>>>>>>>:~$ kubectl get kafkas -o yaml -n my-kafka-project
apiVersion: v1
items:
- apiVersion: kafka.strimzi.io/v1beta2
  kind: Kafka
  metadata:
    annotations:
      kubectl.kubernetes.io/last-applied-configuration: |
        {"apiVersion":"kafka.strimzi.io/v1beta2","kind":"Kafka","metadata":{"annotations":{},"name":"my-cluster","namespace":"my-kafka-project"},"spec":{"entityOperator":{"topicOperator":{},"userOperator":{}},"kafka":{"config":{"default.replication.factor":1,"inter.broker.protocol.version":"2.8","min.insync.replicas":1,"offsets.topic.replication.factor":3,"transaction.state.log.min.isr":1,"transaction.state.log.replication.factor":1},"listeners":[{"name":"plain","port":9092,"tls":false,"type":"internal"},{"name":"tls","port":9093,"tls":true,"type":"internal"},{"configuration":{"bootstrap":{"nodePort":32100}},"name":"external","port":9094,"tls":false,"type":"nodeport"}],"replicas":3,"storage":{"type":"ephemeral"},"version":"2.8.0"},"zookeeper":{"replicas":3,"storage":{"type":"ephemeral"}}}}
    creationTimestamp: "2023-03-30T12:11:57Z"
    generation: 1
    name: my-cluster
    namespace: my-kafka-project
    resourceVersion: "25792563"
    uid: 716d514b-54c4-406f-8c51-8650f4ae12c9
  spec:
    entityOperator:
      topicOperator: {}
      userOperator: {}
    kafka:
      config:
        default.replication.factor: 1
        inter.broker.protocol.version: "2.8"
        min.insync.replicas: 1
        offsets.topic.replication.factor: 3
        transaction.state.log.min.isr: 1
        transaction.state.log.replication.factor: 1
      listeners:
      - name: plain
        port: 9092
        tls: false
        type: internal
      - name: tls
        port: 9093
        tls: true
        type: internal
      - configuration:
          bootstrap:
            nodePort: 32100
        name: external
        port: 9094
        tls: false
        type: nodeport
      replicas: 3
      storage:
        type: ephemeral
      version: 2.8.0
    zookeeper:
      replicas: 3
      storage:
        type: ephemeral
  status:
    clusterId: kWkFxLnDQCCycw0RjIauYw
    conditions:
    - lastTransitionTime: "2023-04-13T06:04:00.647Z"
      status: "True"
      type: Ready
    listeners:
    - addresses:
      - host: my-cluster-kafka-bootstrap.my-kafka-project.svc
        port: 9092
      bootstrapServers: my-cluster-kafka-bootstrap.my-kafka-project.svc:9092
      type: plain
    - addresses:
      - host: my-cluster-kafka-bootstrap.my-kafka-project.svc
        port: 9093
      bootstrapServers: my-cluster-kafka-bootstrap.my-kafka-project.svc:9093
      certificates:
      - |
        -----BEGIN CERTIFICATE-----
        MII+WQD
        -----END CERTIFICATE-----
      type: tls
    - addresses:
      - host: 10.0.21.12
        port: 32100
      bootstrapServers: 10.0.21.12:32100
      type: external
    observedGeneration: 1
kind: List
metadata:
  resourceVersion: ""
  selfLink: ""

As you can see there is no gruop.id property set. What is the default value? I have tried with: empty string, "", " ", null and many more things I read in forums but none of them works.

Thank you very much

[scholzj]

I guess you should consult the NiFi docs what it is. But my guess is that this is the consumer group ID that identifies the consumer group. It is a consumer group option - so it is not in the Kafka CR. It is basically a unique name for a group of consumers which work together (e.g. instances of your NiFi application running in parallel) and it is used to distribute the load among them. But to be clear, I'm not a NiFi user - so I'm basically just guessing what it might mean there.