Chapter 8. Deprecated features

Support for RHEL 7 is deprecated in AMQ Streams 2.5.x. AMQ Streams 2.5.x (LTS) is the last LTS version to support RHEL 7.

In this release, the UseStrimziPodSets feature gate moved to GA, which means it is now permanently enabled and cannot be disabled. For this reason, support for StatefulSet resources to manage pods is no longer available.

The StatefulSet template properties in the Kafka custom resource (.spec.zookeeper.template.statefulSet and .spec.kafka.template.statefulSet) are deprecated and ignored. You should remove them from your custom resources.

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.

Support for type: jaeger tracing 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.

The operation property for configuring operations for ACL rules is deprecated. A new, more-streamlined configuration format using the operations property is now available.

authorization:
  type: simple
  acls:
    - resource:
        type: topic
        name: my-topic
      operations:
        - Read
        - Describe
        - Create
        - Write

The operation property for the old configuration format is deprecated, but still supported.

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 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 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 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 type property of ListenerStatus has been deprecated and will be removed in the future. ListenerStatus is used to specify the addresses of internal and external listeners. Instead of using the type, the addresses are now specified by name.

See ListenerStatus schema reference.

The Cruise Control TLS sidecar has been removed. As a result, the .spec.cruiseControl.tlsSidecar and .spec.cruiseControl.template.tlsSidecar properties are now deprecated. The properties are ignored and will be removed in the future.

The disk and cpuUtilization capacity configuration properties have been deprecated, are ignored, and will be removed in the future. The properties were used in setting capacity limits in optimization proposals to determine if resource-based optimization goals are being broken. Disk and CPU capacity limits are now automatically generated by AMQ Streams.

See Configuring and deploying Cruise Control with Kafka.