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 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 7.5.0:
```
spec:
  image:
    application: confluentinc/cp-server:7.5.0
```
In the same component CR, verify that the CFK init container image tag has been updated during the CFK upgrade process. The image tag should be the current version of CFK, 2.7.0.
```
spec:
  image:
    init: confluentinc/confluent-init-container:2.7.0
```
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, 3.5:
```
spec:
  configOverrides:
    server:
      - inter.broker.protocol.version=3.5
```

Upgrade the component.

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