Chapter 4. Deprecated features

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.

Support for Java 8 was deprecated in Kafka 3.0.0 and AMQ Streams 2.0. Java 8 will be unsupported for all AMQ Streams components, including clients, in the future.

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

Kafka MirrorMaker replicates data between two or more active Kafka clusters, within or across data centers. Kafka MirrorMaker 1 is deprecated for Kafka 3.2.3 and will be removed in Kafka 4.0.0. MirrorMaker 2.0 will be the only version available. MirrorMaker 2.0 is based on the Kafka Connect framework, connectors managing the transfer of data between clusters.

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

If you are using MirrorMaker 1 (referred to as just MirrorMaker in the AMQ Streams documentation), use the KafkaMirrorMaker2 custom resource with the IdentityReplicationPolicy. MirrorMaker 2.0 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 Kafka MirrorMaker 2.0 cluster configuration.

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

The AMQ Streams Identity Replication Policy class (io.strimzi.kafka.connect.mirror.IdentityReplicationPolicy) is now deprecated and will be removed in the future. You can update to use Kafka’s own Identity Replication Policy (class org.apache.kafka.connect.mirror.IdentityReplicationPolicy).

See Kafka MirrorMaker 2.0 cluster configuration.