Kafka Monthly Digest: February 2026

Releases

4.2.0

Kafka brokers and clients

• Share groups (queues) are now ready for production usage. (KIP-932)
• Improvements to share groups such as acquisition lock timeout renewal (KIP-1222), new lag metrics (KIP-1226) and configurations to enforce or not the max fetch record limit (KIP-1206)
• Consistency improvements to all command line tools. They now all support the --bootstrap-server and --command-config flags. (KIP-1147)
• Improvements and new features to many tools including kafka-consumer-perf-test.sh, kafka-producer-perf-test.sh, kafka-e2e-latency.sh and kafka-features.sh. (KIP-1052,  KIP-1172, KIP-1192)
• Monitoring improvements with new metrics and more consistent metric names. (KIP-1100, KIP-1180, KIP-1190, KIP-1207, KIP-1229)
   

Kafka Connect

• Support for external schemas in JSONConverter. (KIP-1054)
• New Allowlist connector client configuration override policy. This will be the new default policy from Kafka 5.0.0, but I recommend adopting it now if possible. (KIP-1188)

Kafka Streams

• Support for dead letter queue (DLQ) in exception handlers. (KIP-1034)
• The new Streams rebalance protocol (based on KIP-848) is now production ready. The default protocol is still classic. (KIP-1071)
• Support for punctuation to be triggered at deterministic times. (KIP-1146)
   

3.9.2

4.0.2

4.1.2

4.3.0

Kafka Improvement Proposals

• KIP-1279: Cluster Mirroring: The KIP proposes bringing built-in cluster mirroring support in the brokers. This is an alternative to MirrorMaker but it would bring significant improvements including exact mirroring with matching offsets between the clusters, and it would simplify operations such as failover and failback. 
   

• KIP-1288: SSL Hot Reload for Kafka Clients: Kafka clients load their credentials at startup. For keys and certificates that are regularly renewed, clients must be restarted to pick up the new ones. This KIP introduces a mechanism for clients to reload their credentials at runtime easing the operational burden of managing secured environments.
   

• KIP-1289: Support Hierarchical Transactional Acknowledgments for Share Groups: At the moment it's not possible to obtain exactly once semantic processing using share groups (queues). This KIP proposes new APIs to enable transactional acknowledgments. This would allow stream processing frameworks like Apache Flink and Apache Spark to provide exactly once semantics when consuming data from share groups.
   

• KIP-1292: New MirrorMaker2 Connector for syncing consumer offsets: In MirrorMaker the MirrorCheckpointConnector handles the offset translation between the clusters. Because it's not possible to maintain a mapping for every single offset, the algorithm it currently uses ensures very precise translation for offsets near the log end offsets but that precision degrades exponentially the older offsets are. This KIP proposes a new algorithm with a constant degradation from the log start to end offsets so it could provide much more accurate translation for older offsets.
   

Community Releases

• Sarama 1.47: Sarama is a pure Golang Kafka client. This release improves the Admin DescribeCluster() API, and the handling of broken connections.
   

Blogs

• Queues for Kafka ready for prime time
• Kafka can be so much more
• Introducing uForwarder: The Consumer Proxy for Kafka Async Queuing
• Bite-Size Streams: Stream to Table Join