Upgrade Confluent Platform¶

When you upgrade Confluent Platform from one version to another, we recommend that you perform the upgrade process separate from making other changes to your clusters, such as scaling up, changing configuration, or rotating credentials.

Note that there are certain configurations that cannot be updated on deployed clusters. See Upgrades and updates for this list.

Upgrade notes¶

The ZooKeeper dependency has been upgraded to 3.8.1 due to 3.6 reaching end-of-life. To bring both your Kafka and ZooKeeper clusters to the latest versions:

(Case A) If upgrading from a Kafka version 2.4 (Confluent Platform version 5.4) or later:

Kafka clusters can be updated directly.
ZooKeeper clusters that are running binaries bundled with Kafka versions 2.4 or later can be updated normally as specified in Upgrade Confluent Platform.

(Case B) If upgrading from a Kafka version older than 2.4 (Confluent Platform version older than 5.4):

Kafka clusters first need to be upgraded to a version 2.4 or later, and earlier than 3.6.
ZooKeeper clusters that are running binaries bundled with a Kafka version that are older than 2.4 need to be updated to the binaries bundled with Kafka versions later than 2.4 and earlier than 3.6.
You could then continue following the steps in Case A above.

Upgrade Confluent Platform¶

Upgrade each Confluent Platform component as below:

In the component CR, update the component image.

CFK uses the following Confluent Platform component images:
- confluentinc/cp-server-connect
- confluentinc/cp-enterprise-control-center
- confluentinc/cp-server
- confluentinc/cp-ksqldb-server
- confluentinc/cp-enterprise-replicator
- confluentinc/cp-schema-registry
- confluentinc/cp-zookeeper
- confluentinc/cp-kafka-rest
The tag is the Confluent Platform release you want to upgrade to.
```
spec:
  image:
    application: <component image>:<tag>
```
For example, to upgrade Kafka to 7.4.5:
```
spec:
  image:
    application: confluentinc/cp-server:7.4.5
```
In the same component CR, update the CFK init container image. The image tag is the version of CFK, 2.6.5:
```
spec:
  image:
    init: confluentinc/confluent-init-container:2.6.5
```
When upgrading Kafka:
1. Set the following properties in the Kafka CR to the broker protocol version of the currently installed Confluent Platform version. To get the broker protocol version, refer to the table in Kafka upgrade documentation.
  
  If you are upgrading from Confluent Platform version 6.2.x or earlier, set log.message.format.version to the version you are upgrading from as shown below.
  
  If you are upgrading from Confluent Platform version 7.0 or later, you do not need to set log.message.format.version.
```
spec:
  configOverrides:
    server:
      - inter.broker.protocol.version=<current Kafka broker protocol version>
      - log.message.format.version=<current Kafka broker protocol version>
```
2. Upgrade Kafka:
```
kubectl apply -f <Kafka CR> --name <namespace>
```
3. After the Kafka brokers have been upgraded, set the properties in the Kafka CR to the target Kafka broker protocol version, 3.4:
```
spec:
  configOverrides:
    server:
      - inter.broker.protocol.version=3.4
```

Upgrade the component.

kubectl apply -f <component CR> --name <namespace>