Chapter 5. Deprecated features

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.

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 Using Streams for Apache Kafka with 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 result, MirrorMaker 1 has also been deprecated in Streams for Apache Kafka as well. If you are using MirrorMaker 1 (referred to as just MirrorMaker in the Streams for Apache Kafka documentation), use MirrorMaker 2 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 Using Streams for Apache Kafka with 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