This 104th edition of the Kafka Monthly Digest covers what happened in the Apache Kafka community in September 2026.
Releases
There is one new release (4.2.2), and three releases are in progress (4.4.0, 4.3.2 and 4.5.0):
4.2.2
Apoorv Mittal released 4.2.2 on September 29. This bug fix release fixes 33 issues. You can find the announcement on the blog and the release plan in the wiki.
4.4.0
Omnia Ibrahim published 4.4.0 RC1 on September 22, followed by RC3 on September 30 but both had release issues (missing artifacts, invalid signatures). A new release candidate, RC4, is expected in the next few days. You can find the release plan in the wiki.
4.3.2
On September 2, Jiunn-Yang Huang volunteered to be the release manager for Kafka 4.3.2. The first release candidate was published on September 29 and the vote is currently ongoing. You can find the release plan in the wiki.
4.5.0
On September 23, Andrew Schofield volunteered to be the release manager for Kafka 4.5.0. The current target date is mid March 2027. You can find the release plan in the wiki.
Kafka Improvement Proposals
- KIP-1373: Client Quota Utilization Metrics: Brokers expose several metrics to track quota usages by users. However these return the absolute usage values without the limits set by the cluster administrator. This KIP proposes adding new metrics exposing quota usage as percentages to help identify users near their limits and whether limits should be adjusted.
- KIP-1376: Support setting TLS named groups: The JVM uses TLS named groups to specify the key exchange algorithms it can use. Since Java 20, they can be set by application logic via the
SSLParameters.setNamedGroups()API. This KIP proposes new configurations so users can configure named groups used by Kafka clients and servers. On supported JVMs, this enables using post-quantum cryptography (PQC) key exchange algorithms to prevent attacks like "Harvest now, decrypt later".
- KIP-1378: Allow Consumer Group Renaming in MirrorMaker 2 Checkpoint Connector: In MirrorMaker the replication policy allows renaming topics as they are mirrored to other clusters. Today when consumer groups are mirrored their names are kept as-is, and for that reason if a group already uses that name on the target cluster, MirrorMaker cannot automatically sync offsets (in that case it only emits checkpoints). This KIP proposes enabling replication policies to rename consumer groups like it's done for topic names.
Community Releases
I selected releases of some open source community projects:
- Debezium 3.7: Debezium is a Change Data Capture platform. This release includes major improvements to all of the existing connectors. It also introduces new connectors for TiDB, Milvus, and SQLite.
- kroxylicious 0.24.0: Kroxylicious is an open source pluggable framework for writing network proxies that understand the Apache Kafka protocol. This release adds SASL termination that enables the proxy to authenticate users. The project also decoupled its APIs from Apache Kafka classes, so plugin developers should now use classes under
io.kroxylicious.kafkainstead oforg.apache.kafka.
Blogs
I selected some interesting blog articles that were published last month:
