Chapter 5. Deprecated features

The features deprecated in this release, and that were supported in previous releases of AMQ Streams, are outlined below.

5.1. Java 8 support removed in AMQ Streams 2.4.0

Support for Java 8 was deprecated in Kafka 3.0.0 and AMQ Streams 2.0. Support for Java 8 was removed in AMQ Streams 2.4.0. This applies to all AMQ Streams components, including clients.

AMQ Streams supports Java 11 and Java 17. Use Java 11 or 17 when developing new applications. Plan to migrate any applications that currently use Java 8 to Java 11 or 17.

If you want to continue using Java 8 for the time being, AMQ Streams 2.2 provides Long Term Support (LTS). For information on the LTS terms and dates, see the AMQ Streams LTS Support Policy.

5.2. OpenTracing

Support for OpenTracing is deprecated.

The Jaeger clients are now retired and the OpenTracing project archived. As such, we cannot guarantee their support for future Kafka versions. We are introducing a new tracing implementation based on the OpenTelemetry project.

5.3. Kafka MirrorMaker 2 identity replication policy

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 AMQ Streams 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 AMQ Streams with MirrorMaker 2.

5.4. Kafka MirrorMaker 1

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 AMQ Streams as well. If you are using MirrorMaker 1 (referred to as just MirrorMaker in the AMQ Streams 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 AMQ Streams with MirrorMaker 2.