Kafka Streams
@kafkastreams.bsky.social
The official Apache Kafka Streams account. Run by the Apache Kafka PMC. Long live the otter.
There is a new KIP-1244 proposing to deprecate the Kafka Streams Scala API, and remove it with the next major release.
Please join the discussion on the dev mailing list if this concerns you.
Please join the discussion on the dev mailing list if this concerns you.
January 13, 2026 at 6:19 PM
There is a new KIP-1244 proposing to deprecate the Kafka Streams Scala API, and remove it with the next major release.
Please join the discussion on the dev mailing list if this concerns you.
Please join the discussion on the dev mailing list if this concerns you.
Reposted by Kafka Streams
π I've built a new interactive simulation of #Kafka Streams, showcasing state stores!
See state stores being restored, switch between RocksDB & in-memory state store behavior,restart tasks. Great for understanding or explaining Kafka Streams!
Try it here: kafkastreamsfieldguide.com/tools/state-...
See state stores being restored, switch between RocksDB & in-memory state store behavior,restart tasks. Great for understanding or explaining Kafka Streams!
Try it here: kafkastreamsfieldguide.com/tools/state-...
December 2, 2025 at 12:22 PM
π I've built a new interactive simulation of #Kafka Streams, showcasing state stores!
See state stores being restored, switch between RocksDB & in-memory state store behavior,restart tasks. Great for understanding or explaining Kafka Streams!
Try it here: kafkastreamsfieldguide.com/tools/state-...
See state stores being restored, switch between RocksDB & in-memory state store behavior,restart tasks. Great for understanding or explaining Kafka Streams!
Try it here: kafkastreamsfieldguide.com/tools/state-...
We are happy to share that the Apache Kafka 4.1.1 bug-fix release is now available!
It contains a critical memory-leak fix for #KafkaStreams and many other fixes. For details see kafka.apache.org/blog#apache_...
Thanks to 32 contributors and Lianet Magrans as our RM.
It contains a critical memory-leak fix for #KafkaStreams and many other fixes. For details see kafka.apache.org/blog#apache_...
Thanks to 32 contributors and Lianet Magrans as our RM.
Apache Kafka
Apache Kafka: A Distributed Streaming Platform.
kafka.apache.org
November 14, 2025 at 5:56 PM
We are happy to share that the Apache Kafka 4.1.1 bug-fix release is now available!
It contains a critical memory-leak fix for #KafkaStreams and many other fixes. For details see kafka.apache.org/blog#apache_...
Thanks to 32 contributors and Lianet Magrans as our RM.
It contains a critical memory-leak fix for #KafkaStreams and many other fixes. For details see kafka.apache.org/blog#apache_...
Thanks to 32 contributors and Lianet Magrans as our RM.
Sub-topologies and co-partitioning are imported concepts. Nice blog post from Expedia:
medium.com/expedia-grou...
medium.com/expedia-grou...
Colocating Input Partitions with Kafka Streams When Consuming Multiple Topics: Sub-Topology Matters!
Understanding how sub-topology design influences partition co-location
medium.com
November 11, 2025 at 8:10 PM
Sub-topologies and co-partitioning are imported concepts. Nice blog post from Expedia:
medium.com/expedia-grou...
medium.com/expedia-grou...
We are excited to announce the Apache Kafka 4.0.1 bug-fix release, containing over 40 fixes!
Thanks to 53 contributors and your RM Christo Lolov.
For more details, checkout the announcement:
kafka.apache.org/blog#apache_...
Thanks to 53 contributors and your RM Christo Lolov.
For more details, checkout the announcement:
kafka.apache.org/blog#apache_...
Apache Kafka
Apache Kafka: A Distributed Streaming Platform.
kafka.apache.org
October 13, 2025 at 7:40 PM
We are excited to announce the Apache Kafka 4.0.1 bug-fix release, containing over 40 fixes!
Thanks to 53 contributors and your RM Christo Lolov.
For more details, checkout the announcement:
kafka.apache.org/blog#apache_...
Thanks to 53 contributors and your RM Christo Lolov.
For more details, checkout the announcement:
kafka.apache.org/blog#apache_...
π¨Kafka Streams 4.1.0 contains a memory leak regression bug: issues.apache.org/jira/browse/...
Be careful upgrading, or wait for 4.1.1 bug-fix release. We plan to get it out quickly.
Be careful upgrading, or wait for 4.1.1 bug-fix release. We plan to get it out quickly.
issues.apache.org
October 6, 2025 at 7:10 PM
π¨Kafka Streams 4.1.0 contains a memory leak regression bug: issues.apache.org/jira/browse/...
Be careful upgrading, or wait for 4.1.1 bug-fix release. We plan to get it out quickly.
Be careful upgrading, or wait for 4.1.1 bug-fix release. We plan to get it out quickly.
Any KIP-1071 experience out there?
Asking for a friend.
Asking for a friend.
September 30, 2025 at 2:34 AM
Any KIP-1071 experience out there?
Asking for a friend.
Asking for a friend.
Reposted by Kafka Streams
π¨ Breaking News from Community Over Code π¨
Introducing The ASFβs New Logo buff.ly/DzgT82w
#CommunityOverCode #opensource
Introducing The ASFβs New Logo buff.ly/DzgT82w
#CommunityOverCode #opensource
September 11, 2025 at 3:12 PM
π¨ Breaking News from Community Over Code π¨
Introducing The ASFβs New Logo buff.ly/DzgT82w
#CommunityOverCode #opensource
Introducing The ASFβs New Logo buff.ly/DzgT82w
#CommunityOverCode #opensource
Apache Kafka 4.1.0 was release!
Most exciting, the new βstreamsβ rebalance protocol is available as early access.
We are happy to announce the Apache Kafka 4.1.0 release!
Please try it out, and let us know how it goes!
kafka.apache.org/blog#apache_...
Most exciting, the new βstreamsβ rebalance protocol is available as early access.
We are happy to announce the Apache Kafka 4.1.0 release!
Please try it out, and let us know how it goes!
kafka.apache.org/blog#apache_...
Apache Kafka
Apache Kafka: A Distributed Streaming Platform.
kafka.apache.org
September 4, 2025 at 5:23 PM
Apache Kafka 4.1.0 was release!
Most exciting, the new βstreamsβ rebalance protocol is available as early access.
We are happy to announce the Apache Kafka 4.1.0 release!
Please try it out, and let us know how it goes!
kafka.apache.org/blog#apache_...
Most exciting, the new βstreamsβ rebalance protocol is available as early access.
We are happy to announce the Apache Kafka 4.1.0 release!
Please try it out, and let us know how it goes!
kafka.apache.org/blog#apache_...
While we are waiting for Apache Kafka 4.1.0 release, the development does not stop. We just completed KIP-1034 (cwiki.apache.org/confluence/d...) which adds a DLQ feature to Kafka Streams. Very exciting!
https://cwiki.apache.org/confluence/disβ¦
July 28, 2025 at 11:19 PM
While we are waiting for Apache Kafka 4.1.0 release, the development does not stop. We just completed KIP-1034 (cwiki.apache.org/confluence/d...) which adds a DLQ feature to Kafka Streams. Very exciting!
Reposted by Kafka Streams
Next at #Current25 a panel discussion on the past, present and future of @kafkastreams.bsky.social. I love the background...the likeness is uncanny...
May 20, 2025 at 1:17 PM
Next at #Current25 a panel discussion on the past, present and future of @kafkastreams.bsky.social. I love the background...the likeness is uncanny...
Reposted by Kafka Streams
Apache Kafka 3.9.1 is now available for download: buff.ly/5ONjJgB
This bug-fix release has several fixes, and most importantly, it adds Java 23 support. #opensource
This bug-fix release has several fixes, and most importantly, it adds Java 23 support. #opensource
June 10, 2025 at 3:18 PM
Apache Kafka 3.9.1 is now available for download: buff.ly/5ONjJgB
This bug-fix release has several fixes, and most importantly, it adds Java 23 support. #opensource
This bug-fix release has several fixes, and most importantly, it adds Java 23 support. #opensource
There is a few more others which are more minor. So we stick with these highlights for now. If you want to know them all (also for older releases), check out the wiki: cwiki.apache.org/confluence/d...
Thatβs a wrap!
\TheEnd
Thatβs a wrap!
\TheEnd
https://cwiki.apache.org/confluence/disβ¦
April 5, 2025 at 5:40 AM
There is a few more others which are more minor. So we stick with these highlights for now. If you want to know them all (also for older releases), check out the wiki: cwiki.apache.org/confluence/d...
Thatβs a wrap!
\TheEnd
Thatβs a wrap!
\TheEnd
KIP-1112: cwiki.apache.org/confluence/d...
Injecting custom boiler plate code into all Processors is now easily possible, via this new βprocessor wrapperβ concept. Useful for PAPI users, but invaluable for the DSL!
\6
Injecting custom boiler plate code into all Processors is now easily possible, via this new βprocessor wrapperβ concept. Useful for PAPI users, but invaluable for the DSL!
\6
https://cwiki.apache.org/confluence/disβ¦
April 5, 2025 at 5:40 AM
KIP-1112: cwiki.apache.org/confluence/d...
Injecting custom boiler plate code into all Processors is now easily possible, via this new βprocessor wrapperβ concept. Useful for PAPI users, but invaluable for the DSL!
\6
Injecting custom boiler plate code into all Processors is now easily possible, via this new βprocessor wrapperβ concept. Useful for PAPI users, but invaluable for the DSL!
\6
KIP-1106: cwiki.apache.org/confluence/d...
This is a shared KIP for the consumer and Kafka Streams. A new auto.offset.reset policy βby durationβ is added. Very useful for tiered storage setups when you donβt want to use βearliestβ but still want to start at some point in the past.
\5
This is a shared KIP for the consumer and Kafka Streams. A new auto.offset.reset policy βby durationβ is added. Very useful for tiered storage setups when you donβt want to use βearliestβ but still want to start at some point in the past.
\5
https://cwiki.apache.org/confluence/disβ¦
April 5, 2025 at 5:40 AM
KIP-1106: cwiki.apache.org/confluence/d...
This is a shared KIP for the consumer and Kafka Streams. A new auto.offset.reset policy βby durationβ is added. Very useful for tiered storage setups when you donβt want to use βearliestβ but still want to start at some point in the past.
\5
This is a shared KIP for the consumer and Kafka Streams. A new auto.offset.reset policy βby durationβ is added. Very useful for tiered storage setups when you donβt want to use βearliestβ but still want to start at some point in the past.
\5
KIP-1104: cwiki.apache.org/confluence/d...
Foreign-key table-table joins are very popular. However, the FK could only be extracted from the value so far. This unnecessary limitation is gone now, by passing in both key and value into the FK-key extractor.
\4
Foreign-key table-table joins are very popular. However, the FK could only be extracted from the value so far. This unnecessary limitation is gone now, by passing in both key and value into the FK-key extractor.
\4
https://cwiki.apache.org/confluence/disβ¦
April 5, 2025 at 5:40 AM
KIP-1104: cwiki.apache.org/confluence/d...
Foreign-key table-table joins are very popular. However, the FK could only be extracted from the value so far. This unnecessary limitation is gone now, by passing in both key and value into the FK-key extractor.
\4
Foreign-key table-table joins are very popular. However, the FK could only be extracted from the value so far. This unnecessary limitation is gone now, by passing in both key and value into the FK-key extractor.
\4
KIP-1091: cwiki.apache.org/confluence/d...
Letβs make KIP-1076 even more useful. A few key metrics like client-state and thread-state are Strings and thus cannot be collected via KIP-714. This KIP adds numerical twins for these metrics to make them collectible!
\3
Letβs make KIP-1076 even more useful. A few key metrics like client-state and thread-state are Strings and thus cannot be collected via KIP-714. This KIP adds numerical twins for these metrics to make them collectible!
\3
https://cwiki.apache.org/confluence/disβ¦
April 5, 2025 at 5:40 AM
KIP-1091: cwiki.apache.org/confluence/d...
Letβs make KIP-1076 even more useful. A few key metrics like client-state and thread-state are Strings and thus cannot be collected via KIP-714. This KIP adds numerical twins for these metrics to make them collectible!
\3
Letβs make KIP-1076 even more useful. A few key metrics like client-state and thread-state are Strings and thus cannot be collected via KIP-714. This KIP adds numerical twins for these metrics to make them collectible!
\3
KIP-1076: cwiki.apache.org/confluence/d...
This is an extension to the famous KIP-714. We now allow to register user metrics for broker side collection. Kafka Streams uses these new APIs to register its own metrics, so all Kafka Streams metrics can now be collected broker side.
\2
This is an extension to the famous KIP-714. We now allow to register user metrics for broker side collection. Kafka Streams uses these new APIs to register its own metrics, so all Kafka Streams metrics can now be collected broker side.
\2
https://cwiki.apache.org/confluence/disβ¦
April 5, 2025 at 5:40 AM
KIP-1076: cwiki.apache.org/confluence/d...
This is an extension to the famous KIP-714. We now allow to register user metrics for broker side collection. Kafka Streams uses these new APIs to register its own metrics, so all Kafka Streams metrics can now be collected broker side.
\2
This is an extension to the famous KIP-714. We now allow to register user metrics for broker side collection. Kafka Streams uses these new APIs to register its own metrics, so all Kafka Streams metrics can now be collected broker side.
\2
Apache Kafka 4.0 was released recently. We got a couple of a cool KIPs shipped.
KIP-1065: cwiki.apache.org/confluence/p...
The ProductionExceptionHandler becomes more flexible. Itβs now also called for retriable errors. This allows you to break (previously infinite) retry loops.
\1
KIP-1065: cwiki.apache.org/confluence/p...
The ProductionExceptionHandler becomes more flexible. Itβs now also called for retriable errors. This allows you to break (previously infinite) retry loops.
\1
https://cwiki.apache.org/confluence/pagβ¦
April 5, 2025 at 5:40 AM
Apache Kafka 4.0 was released recently. We got a couple of a cool KIPs shipped.
KIP-1065: cwiki.apache.org/confluence/p...
The ProductionExceptionHandler becomes more flexible. Itβs now also called for retriable errors. This allows you to break (previously infinite) retry loops.
\1
KIP-1065: cwiki.apache.org/confluence/p...
The ProductionExceptionHandler becomes more flexible. Itβs now also called for retriable errors. This allows you to break (previously infinite) retry loops.
\1
Reposted by Kafka Streams
Next up in the Kafka Streams 101 series: performance optimization!
Admittedly this one goes way beyond just the "101" level, with general tips to incredibly specific optimization techniques.
Check it out to get a handle on your application's performance: bit.ly/43zXoQM
Admittedly this one goes way beyond just the "101" level, with general tips to incredibly specific optimization techniques.
Check it out to get a handle on your application's performance: bit.ly/43zXoQM
Kafka Streams 101: Optimizing your apps for maximum performance
Learn the concepts, configs, and application design strategies to get your Kafka Streams apps running as optimally as possible.
bit.ly
March 11, 2025 at 1:19 AM
Next up in the Kafka Streams 101 series: performance optimization!
Admittedly this one goes way beyond just the "101" level, with general tips to incredibly specific optimization techniques.
Check it out to get a handle on your application's performance: bit.ly/43zXoQM
Admittedly this one goes way beyond just the "101" level, with general tips to incredibly specific optimization techniques.
Check it out to get a handle on your application's performance: bit.ly/43zXoQM
Reposted by Kafka Streams
@intellijidea.com's IDE has a great Apache Kafka plugin.
This is a @kafkastreams.bsky.social's session window changelog topic -- maybe I can figure out how to get support natively for Kafka Stream windowing keys.
This is a @kafkastreams.bsky.social's session window changelog topic -- maybe I can figure out how to get support natively for Kafka Stream windowing keys.
March 5, 2025 at 1:37 PM
@intellijidea.com's IDE has a great Apache Kafka plugin.
This is a @kafkastreams.bsky.social's session window changelog topic -- maybe I can figure out how to get support natively for Kafka Stream windowing keys.
This is a @kafkastreams.bsky.social's session window changelog topic -- maybe I can figure out how to get support natively for Kafka Stream windowing keys.
Writing and a running a Kafka Streams app can be trickier than you'd think! We have some basic examples in the repo but they don't cover everything. Glad to have more material focused on helping new people get into Kafka Streams!
Next entry in the Kafka Streams 101 series: application lifecycle.
Very beginner friendly, but even the pros might find a useful tip or two -- for example: have you heard of the new standby task listener?
Check it out: www.responsive.dev/blog/app-lif...
Very beginner friendly, but even the pros might find a useful tip or two -- for example: have you heard of the new standby task listener?
Check it out: www.responsive.dev/blog/app-lif...
Kafka Streams 101: Application Lifecycle
Learn how to properly start, stop, and manage the lifecycle of Kafka Streams
www.responsive.dev
February 26, 2025 at 10:07 PM
Writing and a running a Kafka Streams app can be trickier than you'd think! We have some basic examples in the repo but they don't cover everything. Glad to have more material focused on helping new people get into Kafka Streams!
Reposted by Kafka Streams
We're keeping the ball rolling on the Kafka Streams 101 series with yet another blog post! This time the focus is on configuration, and breaking down the most important configs to focus on for various needs (such as correctness, resiliency, etc)
Check it out here: www.responsive.dev/blog/importa...
Check it out here: www.responsive.dev/blog/importa...
Kafka Streams 101: The Most Important Configs
Learn which configurations are most critical for a reliable and efficient deployment
www.responsive.dev
February 18, 2025 at 10:40 PM
We're keeping the ball rolling on the Kafka Streams 101 series with yet another blog post! This time the focus is on configuration, and breaking down the most important configs to focus on for various needs (such as correctness, resiliency, etc)
Check it out here: www.responsive.dev/blog/importa...
Check it out here: www.responsive.dev/blog/importa...
Reposted by Kafka Streams
The 2025 blog post series has begun and we're kicking things off with the "official" Kafka Streams upgrade-guide -- check it out for best practices when setting up a new app, rules for safe vs unsafe upgrades, and tips for making the process go smoothly: www.responsive.dev/blog/topolog...
Kafka Streams 101: Topology Upgrades
A Kafka Streams 101 lesson to learn how to identify unsafe changes to a topology and the techniques to mitigate them
www.responsive.dev
February 13, 2025 at 7:29 PM
The 2025 blog post series has begun and we're kicking things off with the "official" Kafka Streams upgrade-guide -- check it out for best practices when setting up a new app, rules for safe vs unsafe upgrades, and tips for making the process go smoothly: www.responsive.dev/blog/topolog...
Reposted by Kafka Streams
February 7, 2025 at 5:43 PM