26.2. Downgrading KRaft-based Kafka clusters and client applications

Procedure

1. Update the Kafka cluster configuration.

   oc edit kafka <kafka_configuration_file>

2. Change the metadataVersion version to a version supported by the Kafka version you are downgrading to; leave the Kafka.spec.kafka.version unchanged at the current Kafka version.

   For example, if downgrading from Kafka 3.7.0 to 3.6.0:

   apiVersion: kafka.strimzi.io/v1beta2
   kind: Kafka
   metadata:
     name: my-cluster
   spec:
     kafka:
       replicas: 3
       metadataVersion: 3.6-IV2 

   1

   
       version: 3.7.0 

   2

   
       # ...

   1

   Metadata version is changed to a version supported by the earlier Kafka version.

   2

   Kafka version is unchanged.

   注意

   The value of metadataVersion must be a string to prevent it from being interpreted as a floating point number.

3. Save the change, and wait for Cluster Operator to update .status.kafkaMetadataVersion for the Kafka resource.

4. Change the Kafka.spec.kafka.version to the previous version.

   For example, if downgrading from Kafka 3.7.0 to 3.6.0:

   apiVersion: kafka.strimzi.io/v1beta2
   kind: Kafka
   metadata:
     name: my-cluster
   spec:
     kafka:
       replicas: 3
       metadataVersion: 3.6-IV2 

   1

   
       version: 3.6.0 

   2

   
       # ...

   1

   Metadata version is supported by the Kafka version.

   2

   Kafka version is changed to the new version.

5. If the image for the Kafka version is different from the image defined in STRIMZI_KAFKA_IMAGES for the Cluster Operator, update Kafka.spec.kafka.image.

   See 第 25.2.3 节 “Kafka version and image mappings”.

6. Wait for the Cluster Operator to update the cluster.

   You can check the downgrade has completed successfully from the status of the Kafka resource.

7. Downgrade all client applications (consumers) to use the previous version of the client binaries.

   The Kafka cluster and clients are now using the previous Kafka version.