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new a95453bc54 MINOR: Add blog post for 4.3.0 (#861)
a95453bc54 is described below
commit a95453bc542933092face2cbc5bb3dbe74630aed
Author: Mickael Maison <[email protected]>
AuthorDate: Fri May 22 10:51:50 2026 +0200
MINOR: Add blog post for 4.3.0 (#861)
Reviewers: Reviewers: Christo Lolov <[email protected]>, Josep Prat
<[email protected]>, Matthias J. Sax <[email protected]>, Lianet Magrans
<[email protected]>
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+---
+date: 2026-05-22
+title: Apache Kafka 4.3.0 Release Announcement
+linkTitle: AK 4.3.0
+author: Mickael Maison
+aliases:
+ - /blog/2026/05/22/apache-kafka-4.3.0-release-announcement/
+---
+
+<!--
+ Licensed to the Apache Software Foundation (ASF) under one or more
+ contributor license agreements. See the NOTICE file distributed with
+ this work for additional information regarding copyright ownership.
+ The ASF licenses this file to You under the Apache License, Version 2.0
+ (the "License"); you may not use this file except in compliance with
+ the License. You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+-->
+
+We are proud to announce the release of Apache Kafka® 4.3. This release
contains many new features and improvements. This blog post will highlight some
of the more prominent ones. For a full list of changes, be sure to check the
[release notes](https://downloads.apache.org/kafka/4.3.0/RELEASE_NOTES.html).
+
+With 25 KIPs and over 600 commits since 4.2.0, this release introduces many
new features, improvements and bug fixes to all the components.
+
+
+See the [Upgrading to
4.3](https://kafka.apache.org/documentation.html#upgrade_4_3_0) section in the
documentation for the list of notable changes and detailed upgrade steps.
+
+## Deprecation Notices
+* [KIP-1244 Drop support for streams-scala in Kafka 5.0 (deprecate in
4.3)](https://cwiki.apache.org/confluence/x/r4LMFw)
+ Deprecates the streams-scala module. Marked for removal in Apache Kafka 5.0.
+
+* [KIP-1237: Deprecate group.coordinator.rebalance.protocols
config](https://cwiki.apache.org/confluence/x/jIqmFw)
+ Deprecates the `group.coordinator.rebalance.protocols` broker configuration.
Marked for removal in Apache Kafka 5.0.
+
+* [KIP-1280: Update MirrorMaker to use KIP-877 to emit
metrics](https://cwiki.apache.org/confluence/x/a4s8G)
+ Deprecates the existing MirrorMaker metrics. They are marked for removal in
Apache Kafka 5.0. Users should transition to the new metric names.
+
+## Kafka Broker, Controller, Producer, Consumer and Admin Client
+
+* [KIP-1023: Follower fetch from tiered
offset](https://cwiki.apache.org/confluence/x/8op3EQ)
+ Adds a new broker configuration, `follower.fetch.last.tiered.offset.enable`
(default: `false`). When enabled the last tiered offset is used as the start
offset when bootstrapping a new follower.
+
+* [KIP-1066: Mechanism to cordon brokers and log
directories](https://cwiki.apache.org/confluence/x/Lg_TEg)
+ Introduces a new configuration, `cordoned.log.dirs` to cordon log
directories. New partitions cannot be placed on a cordoned log directory. This
can be used when scaling or [decommissioning brokers or log
directories](https://kafka.apache.org/43/operations/basic-kafka-operations/#decommissioning-brokers-and-log-directories).
+
+* [KIP-1196: Introduce group.coordinator.append.max.buffer.size
config](https://cwiki.apache.org/confluence/x/hA5JFg)
+ Introduces the `group.coordinator.append.max.buffer.size` and
`share.coordinator.append.max.buffer.size` configurations to set the maximum
buffer size the coordinators can use. There are also metrics to track the
buffer usage.
+
+* [KIP-1208: Add prefix to TopicBasedRemoteLogMetadataManagerConfig to enable
setting admin configs](https://cwiki.apache.org/confluence/x/vYqhFg)
+ Introduces a new prefix `remote.log.metadata.admin.` for setting
configurations for the admin client used by the tiered storage's
`RemoteLogMetadataManager`.
+
+* [KIP-1211: Align the behavior of num.partitions and
default.replication.factor for topic
creation](https://cwiki.apache.org/confluence/x/WIrHFg)
+ Fixes inconsistencies how `num.partitions` and `default.replication.factor`
were applied when creating topics.
+
+* [KIP-1219: Configurations for KRaft Fetch and FetchSnapshot Byte
Size](https://cwiki.apache.org/confluence/x/yQkGFw)
+ Adds new broker configurations, `controller.quorum.fetch.snapshot.max.bytes`
and `controller.quorum.fetch.max.bytes`, to control the maximum amount of data
Fetch and FetchSnapshot requests can retrieve.
+
+* [KIP-1235: Correct the default min.insync.replicas to 2 for the
__remote_log_metadata topic](https://cwiki.apache.org/confluence/x/yommFw)
+ Adds a new broker configuration, `remote.log.metadata.topic.min.isr`, to set
the minimum in-sync replicas for the internal topic used by tiered storage.
+
+* [KIP-1240: Additional group configurations for share
groups](https://cwiki.apache.org/confluence/x/tIHMFw)
+ Adds a number of new broker and group configurations to control the behavior
of share groups.
+
+* [KIP-1251: Assignment epochs for consumer
groups](https://cwiki.apache.org/confluence/x/8ITMFw)
+ Improves the member epoch validation logic to avoid unnecessary fencing of
group members.
+
+* [KIP-1257: Partition Size Percentage Metrics for Storage
Monitoring](https://cwiki.apache.org/confluence/x/MAEXG)
+ Introduces new metrics to track how much of the maximum retention each
topic-partition currently uses.
+
+* [KIP-1258: Add Support for OAuth Client Assertion to client_credentials
Grant Type](https://cwiki.apache.org/confluence/x/dwEXG)
+ Adds support for client assertion authentication to client_credentials grant
type with OAuth to enhance security and compatibility with OAuth providers.
+
+* [KIP-1263: Group Coordinator Assignment Batching and
Offload](https://cwiki.apache.org/confluence/x/DIE8G)
+ Improves the group coordinator assignment logic to avoid recomputing
assignments when unnecessary.
+
+* [KIP-1274: Deprecate and remove support for Classic rebalance protocol in
KafkaConsumer (Phase 1)](https://cwiki.apache.org/confluence/x/PoY8G)
+ Logs a message when starting a consumer with the `classic` rebalance
protocol recommending to use the new consumer rebalance protocol instead as the
`classic` protocol will be deprecated in a future release.
+
+## Kafka Streams
+
+* [KIP-1035: StateStore managed changelog
offsets](https://cwiki.apache.org/confluence/x/aQviEQ)
+ Adds methods to the `StateStore` API to manage changelog offsets. This is an
internal runtime change, and only relevant for custom `StateStore`
implementations.
+
+* [KIP-1247: Make Bytes utils class part of the public
API](https://cwiki.apache.org/confluence/x/DYTMFw)
+ Exposes the `Bytes` class as part of the public API so it appears in the
javadoc.
+
+* [KIP-1250: Add metric to track size of in-memory state
stores](https://cwiki.apache.org/confluence/x/noTMFw)
+ Adds new metrics tracking the number of keys in the in-memory state stores.
+
+* [KIP-1259: Add configuration to wipe Kafka Streams local state on
startup](https://cwiki.apache.org/confluence/x/XgIXG)
+ Adds a new configuration, `state.cleanup.dir.max.age.ms`, to automatically
delete state directories that have not been modified for that duration on
startup.
+
+* [KIP-1270: Extend ProcessingExceptionHandler for
GlobalThread](https://cwiki.apache.org/confluence/x/qIE8G)
+ Adds a new configuration, `processing.exception.handler.global.enabled`, to
enable `ProcessingExceptionHandler` to handle `GlobalKTable` exceptions.
+
+* [KIP-1271: Allow to Store Headers in State
Stores](https://cwiki.apache.org/confluence/x/QIM8G)
+ Extends the Processor API to support record headers in state stores.
+
+* [KIP-1285: DSL Opt-in Support for Headers-Aware State
Stores](https://cwiki.apache.org/confluence/x/4ow8G)
+ Exposes Headers-Aware State Stores (KIP-1271) to the DSL API.
+
+## Kafka Connect
+
+* [KIP-1239: Batch offset translation in
RemoteClusterUtils](https://cwiki.apache.org/confluence/x/h4HMFw)
+ Adds a new method `RemoteClusterUtils.translateOffsets()` to translate the
committed offsets of several consumer groups at the same time.
+
+* [KIP-1273: Improve Connect configurable components
discoverability](https://cwiki.apache.org/confluence/x/J4U8G)
+ Introduces a new interface, `ConnectPlugin`, that all Kafka Connect plugins
implement to ensure common methods across all plugin types.
+
+* [KIP-1280: Update MirrorMaker to use KIP-877 to emit
metrics](https://cwiki.apache.org/confluence/x/a4s8G)
+ Adds a new configuration, `metric.names.formats`, for
`MirrorSourceConnector` and `MirrorCheckpointConnector` to opt-in to the new
metric names.
+
+
+## Summary
+
+Ready to get started with Apache Kafka 4.3.0? Check out all the details in the
[upgrade notes](https://kafka.apache.org/documentation.html#upgrade_4_3_0) and
the [release
notes](https://downloads.apache.org/kafka/4.3.0/RELEASE_NOTES.html), and
[download](https://kafka.apache.org/downloads) Apache Kafka 4.3.0.
+
+This was a community effort, so thank you to everyone who contributed to this
release, including all our users and our 147 contributors (and 3 AIs):
+高春晖, 조형준, Abhijeet Kumar, Abhinav Dixit, Alieh Saeedi, Alyssa Huang, Andrew
Schofield, Aneesh Garg, Angelo R., Anton Vasanth, ANUSHREE BONDIA, Apoorv
Mittal, Arpit Goyal, Artem Livshits, averemee-si, Bill Bejeck, Bolin Lin,
Calvin Liu, Chang-Chi Hsu, Chang-Yu Huang, Chia-Ping Tsai, Chia-Yi Chiu,
ChickenchickenLove, Chih-Yuan Chien, Chirag Wadhwa, Chris Egerton, Christo
Lolov, Claude, Claude Sonnet 4.6, Copilot, cui, Dale Lane, David Arthur, David
Jacot, Deepak Goyal, Dejan Stojadinović, [...]
