Release Dates

• KIP Freeze: 09 Jun 2021 (A KIP must be accepted by this date in order to be considered for this release. Note, any KIP that may not be implemented in a week, or that might destabilize the release, should be deferred.)
• Feature Freeze (new date): 30 Jun 2021 (major features merged & working on stabilization, minor features have PR, release branch cut; anything not in this state will be automatically moved to the next release in JIRA)
• Code Freeze (new date): 14 Jul 2021
• At least two weeks of stabilization will follow Code Freeze.

These dates are goals and subject to change, but we expect to stay on the Time Based Release Plan unless unexpected critical issues come up. While the earliest possible release date is 2w after code freeze, release candidates (RCs) will roll out as needed until the release vote passes.

The release manager is Konstantine Karantasis

How to Contribute

Before code freeze:

• Participate in votes and discussions to land or postpone the open KIPs.
• Review patches. We anticipate that this release, as it usually happens, will be bottlenecked mostly on reviews. The more reviewers, the more content we can fit in.
• Write unit/integration/system tests. We want to preserve the tradition of high-quality releases in Apache Kafka. 

After code freeze:

• Write more unit/integration/system tests. We want to preserve the tradition of high-quality releases in Apache Kafka.
• Improve documentation.
• Test the release candidates. 
• Open blocker JIRAs on critical issues found. Open non-blocker JIRAs on any other issues found.
• Fix critical bugs.
• Review bug fixes.
• Vote on release candidates. Even though only PMC votes are binding, community votes are super important as we evaluate the readiness of the release.

Open Issues

Also feel free to refer to this release page for more details of the included tickets (requires log in to the Apache Kafka Jira project).

Planned KIP Content

Note: The planned content is not binding - final content will be based the features committed by branch-cutting date. See Kafka Improvement Proposals for the full list of KIPs.

KIP	JIRA	Component
KIP-751: Drop support for Scala 2.12 in Kafka 4.0 (deprecate in 3.0)		Documentation
KIP-750: Drop support for Java 8 in Kafka 4.0 (deprecate in 3.0)		Documentation
KIP-746: Revise KRaft Metadata Records		Core
KIP-745: Connect API to restart connector and tasks		Connect
KIP-744: Migrate TaskMetadata and ThreadMetadata to an interface with internal implementation		Streams
KIP-743: Remove config value 0.10.0-2.4 of Streams built-in metrics version config		Streams
KIP-741: Change default serde to be null		Streams
KIP-740: Clean up public API in TaskId and fix TaskMetadata#taskId()		Streams
KIP-738: Removal of Connect's internal converter properties		Connect
KIP-735: Increase default consumer session timeout		Clients
KIP-734: Improve AdminClient.listOffsets to return timestamp and offset for the record with the largest timestamp		Clients
KIP-733: change Kafka Streams default replication factor config		Streams
KIP-732: Deprecate eos-alpha and replace eos-beta with eos-v2		Streams
KIP-730: Producer ID generation in KRaft mode		Core, Clients
KIP-725: Streamlining configurations for WindowedSerializer and WindowedDeserializer.		Streams
KIP-724: Drop support for message formats v0 and v1		Core, Clients
KIP-722: Enable connector client overrides by default		Connect
KIP-721: Enable connector log contexts in Connect Log4j configuration		Connect
KIP-720: Deprecate MirrorMaker v1		Core
KIP-716: Allow configuring the location of the offset-syncs topic with MirrorMaker2		MirrorMaker
KIP-715: Expose Committed offset in streams		Streams
KIP-709: Extend OffsetFetch requests to accept multiple group ids.		Core, Clients
KIP-707: The future of KafkaFuture		Clients
KIP-699: Update FindCoordinator to resolve multiple Coordinators at a time		Core, Clients
KIP-695: Further Improve Kafka Streams Timestamp Synchronization		Streams
KIP-679: Producer will enable the strongest delivery guarantee by default		Clients
KIP-666: Add Instant-based methods to ReadOnlySessionStore		Streams
KIP-633: Drop 24 hour default of grace period in Streams		Streams
KIP-630: Kafka Raft Snapshot		Core
KIP-623: Add "internal-topics" option to streams application reset tool		Streams, Tools
KIP-622: Add currentSystemTimeMs and currentStreamTimeMs to ProcessorContext		Streams
KIP-466: Add support for List<T> serialization and deserialization		Clients, Streams

Postponed to subsequent release