Chapter 7. Deprecated features

See the Streams for Apache Kafka Custom Resource API Reference.

Support for Java 11 is deprecated in Kafka 3.7.0 and Streams for Apache Kafka 2.7.0. Java 11 will be unsupported for all Streams for Apache Kafka components, including clients, in the future.

Streams for Apache Kafka supports Java 17. Use Java 17 when developing new applications. Plan to migrate any applications that currently use Java 11 to 17.

The bidirectional Topic Operator is deprecated and will be removed in the 2.8 release. The bidirectional Topic Operator is not supported in KRaft mode. The unidirectional Topic Operator, which is supported in KRaft mode, will be permanently enabled in the 2.8 release.

You can use configuration providers to load configuration data from external sources for all Kafka components, including producers and consumers.

Previously, you could enable the secrets.io.strimzi.kafka.EnvVarConfigProvider environment variable configuration provider using the config.providers properties in the spec configuration of a component. However, this provider is now deprecated and will be removed in the future. Therefore, it is recommended to update your implementation to use Kafka’s own environment variable configuration provider (org.apache.kafka.common.config.provider.EnvVarConfigProvider) to provide configuration properties as environment variables.

apiVersion: kafka.strimzi.io/v1beta2
kind: KafkaConnect
metadata:
  name: my-connect
  annotations:
    strimzi.io/use-connector-resources: "true"
spec:
  # ...
  config:
    # ...
    config.providers: env
    config.providers.env.class: org.apache.kafka.common.config.provider.EnvVarConfigProvider
  # ...

apiVersion: kafka.strimzi.io/v1beta2
kind: KafkaConnect
metadata:
  name: my-connect
  annotations:
    strimzi.io/use-connector-resources: "true"
spec:
  # ...
  config:
    # ...
    config.providers: env
    config.providers.env.class: org.apache.kafka.common.config.provider.EnvVarConfigProvider
  # ...

Identity replication policy is a feature used with MirrorMaker 2 to override the automatic renaming of remote topics. Instead of prepending the name with the source cluster’s name, the topic retains its original name. This setting is particularly useful for active/passive backups and data migration scenarios.

To implement an identity replication policy, you must specify a replication policy class (replication.policy.class) in the MirrorMaker 2 configuration. Previously, you could specify the io.strimzi.kafka.connect.mirror.IdentityReplicationPolicy class included with the Streams for Apache Kafka mirror-maker-2-extensions component. However, this component is now deprecated and will be removed in the future. Therefore, it is recommended to update your implementation to use Kafka’s own replication policy class (org.apache.kafka.connect.mirror.IdentityReplicationPolicy).

See Configuring Kafka MirrorMaker 2.

Kafka MirrorMaker replicates data between two or more active Kafka clusters, within or across data centers. Kafka MirrorMaker 1 was deprecated in Kafka 3.0.0 and will be removed in Kafka 4.0.0. MirrorMaker 2 will be the only version available. MirrorMaker 2 is based on the Kafka Connect framework, connectors managing the transfer of data between clusters.

As a consequence, the Streams for Apache Kafka KafkaMirrorMaker custom resource which is used to deploy Kafka MirrorMaker 1 has been deprecated. The KafkaMirrorMaker resource will be removed from Streams for Apache Kafka when Kafka 4.0.0 is adopted.

If you are using MirrorMaker 1 (referred to as just MirrorMaker in the Streams for Apache Kafka documentation), use the KafkaMirrorMaker2 custom resource with the IdentityReplicationPolicy class. MirrorMaker 2 renames topics replicated to a target cluster. IdentityReplicationPolicy configuration overrides the automatic renaming. Use it to produce the same active/passive unidirectional replication as MirrorMaker 1.

See Configuring Kafka MirrorMaker 2.

The following Kafka Bridge span attributes are deprecated with replacements shown where applicable:

Kafka Bridge uses OpenTelemetry for distributed tracing. The changes are inline with changes to OpenTelemetry semantic conventions. The attributes will be removed in a future release of the Kafka Bridge