1.发布时间

KIP Freeze时间：2021年6月9日

Feature Freeze时间：2021年6月30日

Code Freeze时间：2021年7月14日

代码封板后，最少需要保持2周的稳定期。

2.版本需求

Kafka3.0.0改动量较大，对以下32个特性进行了开发。

KIP-751: Drop support for Scala 2.12 in Kafka 4.0 (deprecate in 3.0)

KIP-750: Drop support for Java 8 in Kafka 4.0 (deprecate in 3.0)

KIP-746: Revise KRaft Metadata Records

KIP-745: Connect API to restart connector and tasks

KIP-744: Migrate TaskMetadata and ThreadMetadata to an interface with internal implementation

KIP-743: Remove config value 0.10.0-2.4 of Streams built-in metrics version config

KIP-741: Change default serde to be null

KIP-740: Clean up public API in TaskId and fix TaskMetadata#taskId()

KIP-738: Removal of Connect's internal converter properties

KIP-735: Increase default consumer session timeout

KIP-734: Improve AdminClient.listOffsets to return timestamp and offset for the record with the largest timestamp

KIP-733: change Kafka Streams default replication factor config

KIP-732: Deprecate eos-alpha and replace eos-beta with eos-v2

KIP-730: Producer ID generation in KRaft mode

KIP-725: Streamlining configurations for WindowedSerializer and WindowedDeserializer.

KIP-724: Drop support for message formats v0 and v1

KIP-722: Enable connector client overrides by default

KIP-721: Enable connector log contexts in Connect Log4j configuration

KIP-720: Deprecate MirrorMaker v1

KIP-716: Allow configuring the location of the offset-syncs topic with MirrorMaker2

KIP-715: Expose Committed offset in streams

KIP-709: Extend OffsetFetch requests to accept multiple group ids.

KIP-707: The future of KafkaFuture

KIP-699: Update FindCoordinator to resolve multiple Coordinators at a time

KIP-695: Further Improve Kafka Streams Timestamp Synchronization

KIP-679: Producer will enable the strongest delivery guarantee by default

KIP-666: Add Instant-based methods to ReadOnlySessionStore

KIP-633: Drop 24 hour default of grace period in Streams

KIP-630: Kafka Raft Snapshot

KIP-623: Add "internal-topics" option to streams application reset tool

KIP-622: Add currentSystemTimeMs and currentStreamTimeMs to ProcessorContext

KIP-466: Add support for List<T> serialization and deserialization