Duplicate CRs for same kafka topic

[Sharad-SKJ052]

Hi Team ,
We are running on Kubernetes version 1.28 and kafka version 3.4.0 .
We are using boiler plate kafka cluster code which is available on strimzi GitHub with slight modification.
We are trying to create below topic

apiVersion: kafka.strimzi.io/v1beta2
kind: KafkaTopic
metadata: 
  labels: 
    strimzi.io/cluster: test-kafka
  name: abc.test.group.topic.internal.any.v2
  namespace: kafka
spec:
  topicName: ABC.test.group.topic.internal.any.v2
  partitions: 3
  replicas: 3
  config: 
    retention.ms: 259200000
    segment.bytes: 1073741824
    cleanup.policy: delete
    delete.retention.ms: 86400000
    max.message.bytes: 2097164
    min.compaction.lag.ms: 0
    retention.bytes: -1
    segment.ms: 604800000

In the cluster when I am applying the above configuration it is creating two topic , one with the provided CR and another having the CR name appended with some hash value .

My assumption here is 2nd topic is being created by strimzi directly.

abc.test.group.topic.internal.any.v2                                                                                               test-kafka   3            3                    True
abc.test.group.topic.internal.any.v2---3b2f256bea4edecca0d007a1def60143be9fbf50                                                    test-kafka   3            3                    

Is there any specific property which we have to define on the cluster to stop this behaviour.
Any insights here would be valuable

FYI - @scholzj

[scholzj]

This might be caused by various things. For example the topic being created first by your Kafka client is you have topic auto.creation enabled. If you check the configuration of the other topic and se that it has the Kafka defaults, it wuld suggest this might be the case.

Maybe you should consider upgrading and using the Unidirectional Topic Operator that works a bit differently and might not do this.

[AAR256]

@scholzj Any other kafka property to consider for this issue. In our setup, I have validated that Kafka cluster config - auto.creation is set to false. I have also validated that there are no connectors running in the cluster with creation enabled as well. Also, seems really weird that out of 20+ kafka clusters running with exactly same properties and same versions only one of them is having this issue.

[scholzj]

No, I don't think I have anything else than the two ideas I shared earlier. Sorry.