Apache Cassandra Changelog

Our monthly roundup of key activities and knowledge to keep the community informed.

Release Notes


Available since 7th September, the latest release of Apache Cassandra is 4.0.1, (pgp, sha256, and sha512). This was a rapid release to fix a critical bug in Gossip on large clusters. Please read the release notes and let us know if you encounter any problems.

Note: As the docs are not yet updated, the bintray location for Debian users is replaced with the ASF’s JFrog Artifactory location.

See the download section for the latest stable and older supported versions of source and binary distributions.

To stay up-to-date, we recommend joining the Cassandra mailing list.

Community Notes

Updates on Cassandra Enhancement Proposals (CEPs), how to contribute, and other community activities.

Are you new to the project? We have a handy ‘Contributing to Cassandra’ page on how to get involved and get started. Additionally, we have established two quick labels you should take a look at if you are new to the project. One is for “Failing Tests” and the other corresponds to our “Low Hanging Fruit”. Feel free to self-select a ticket to work on. Any of these tickets should be of appropriate complexity for someone new to the project to tackle. Just remember to put a note on the ticket. You can also reach out on the ASF Slack in the #cassandra-dev Slack channel. Use @cassandra_mentors to contact any of the 13 designated Cassandra mentors!

Read PMC member Josh McKenzie’s latest bi-weekly update for ongoing discussions and the latest on ticket progress.


A massive thank you goes to Lorina Poland for converting all the Cassandra documentation from reStructuredText to AsciiDoc for the new website and another heartfelt thank you to Mick Semb Wever for getting the ticket over the line by working over the holiday period. We also wouldn’t have the site without Anthony Grasso’s extensive work moving us to the Antora platform. Thank you all! 👏

New Cassandra documentation website
Take a look at the newly updated Cassandra documentation site.


Not sure what branch to target with your work? Josh McKenzie has put together a wiki page


We have established a Build Lead role and we are seeking more volunteers. The position is inspired by the ‘Build Baron’ role used in MongoDB, but more focused on triaging test failures and database correctness, but it may evolve into a performance regression and change point triage role in the future. Read the wiki page for what’s involved in this rotating position and sign-up!


The discussion for CEP-19 Trie Memtable Implementation is underway. Memtables can become a pain point for memory management and garbage collection, Branimir Lambov is proposing an alternative memtable implementation based on tries. Join the discussion if you have an interest in high-performance data structures!


Paulo Motta has started a thread on the mailing list asking contributors to start tagging Jira tickets and submit ideas for the Google Summer of Code (GSOC). We’ll be posting more details on our program later in February, but the key thing to highlight is that GSoC will not be solely focused on students and open to anyone over 18.


As the Apache Cassandra ecosystem matures, we’re are beginning to chart a way forward for non-developer roles, such as marketing (see last year’s report on marketing contributions), website editing, and developer evangelism to become project committers.


Ekaterina Dimitrova drove a discussion about the future of UDF as it relates to recent Cassandra releases, JavaScript, and JDK17. The TL;DR is that we will target a pluggable hooks API for UDFs and let the ecosystem maintain and evolve externally.


The wiki now includes a formalized guide to the Cassandra Continuous Integration process and covers such questions as what CI criteria are we using to gate minor and major releases?

User Space


“Netflix uses Apache Cassandra heavily to satisfy its ever-growing persistence needs on its mission to entertain the world. We have been experimenting and partially using the 4.0 beta in our environments and its features like Audit Logging and backpressure.” - Vinay Chella


“I love the way we can grow or resize our Cassandra clusters with ease and also support for multi-DC and multi-Cloud is designed at core." - Sarma Pydipally

Do you have a Cassandra case study to share? Email cassandra@constantia.io.