Our monthly roundup of key activities and knowledge to keep the community informed.
The latest release of Apache Cassandra is 4.0.5 (pgp, sha256, sha512), which we announced on 18 August 2022. Crucially, this release contains CASSANDRA-15511, which will significantly reduce allocations and improve the write throughput, particularly on collections and contended partitions.
While this is the Changelog highlight activities for July, we want to acknowledge the CentOS 7 issue, which will be resolved in Apache Cassandra 4.0.6. This will soon be out and will re-add support for CentOS 7.
Please read the 4.0.5 release notes and let us know if you encounter any problems.
Our focus remains on the tickets that block the beta release and release candidate for Apache Cassandra 4.1. We have only a handful of unassigned tickets left and these would be a great introduction for someone new to contributing to the project (see details, below, on how to help).
The other supported releases remain Apache Cassandra 3.11 (3.11.13, pgp, sha256, sha512) and 3.0 series (3.0.27, pgp, sha256, sha512) and both are bug fixes.
Note: For this release cycle only, we will continue to support 3.0. as well as the 3.11., 4.0., and 4.1 latest patch versions. See Behind the Scenes of an Apache Cassandra Release for more details.
See the download section for the latest stable and older supported versions of source and binary distributions. Please make sure you read the additional information on the Download page as the Debian and RedHat package repositories have moved.
To stay up-to-date, we recommend joining the Cassandra mailing lists.
Updates on Cassandra Enhancement Proposals (CEPs), how to contribute, and other community activities.
For newcomers to the project, we have a useful ‘Contributing to Cassandra’ page for how to get involved and get started. We would also recommend reading the overview of the C* architecture.
If you’d like to help us get 4.1 over the line, check out the unassigned tickets marked as beta blockers. These are great candidates for someone new to the project.
We also recommend viewing two Jira ticket queries we’ve created. One is a Kanban board for “Failing Tests” tickets that are unassigned and the other corresponds to our Low Hanging Fruit or “Starter Tickets” for 4.0.x and 4.1.x. 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 assign yourself to the ticket and acknowledge the status, such as ‘Work in Progress’ and ‘Needs Comitter/Patch Available’ when you submit your patch. You can also reach out on the ASF Slack in the #cassandra-dev Slack channel. We have 13 mentors ready to help, and you can contact them by using @cassandra_mentors.
You can also read PMC member Josh McKenzie’s latest bi-weekly update for ongoing discussions and the latest on ticket progress.
A huge thanks to everyone who worked on the Cassandra World Party this year, whether they moderated, presented a talk, or helped behind the scenes. Thank you also to the community for turning up and supporting the event! 🙏
You can catch up with all the livestreams and talks from the three sessions across three time zones by reading our recap blog.
The Project Management Committee (PMC) is pleased to announce that Jacek Lewandowski has been invited to become a committer, and he has accepted! Thanks for all your contributions, Jacek! 👏
The community would also like to offer our appreciation to Nate McCall, who stepped down from the PMC chair role in July. Thanks for all your many years of hard work, Nate!👏
The position of chair is an administrative position that interfaces with the Apache Software Foundation Board, by submitting regular reports about project status and health. Read more about the PMC chair role on Apache projects. For anyone unaware of how ASF projects are run, you can learn more about PMCs and the various roles by reading the ASF guide.
And the cycle continues with the announcement of Mick Semb Wever as the new PMC chair and we wish him the best of luck in the role! 👍
The next episode of The Apache Cassandra Corner podcast is available now. Host, Aaron Ploetz, discovers what’s really happening when you turn on your smart TV by chatting to Jeff Beck, Director at SmartThings. The conversation covers Apache Cassandra’s role in powering your entertainment and Jeff’s experience of supporting Cassandra at a global scale.
As part of the implementation work for CEP-15 General-Purpose Transactions, Blake Eggleston has been drafting syntax for Accord, the new leaderless timestamp protocol. There was much discussion about the right approach, which has now converged, defining the syntax we will use for multi-key transactions and bringing CEP-15 ever closer.
Also affecting CEP-15, Avi Kivity opened up a ticket about the challenges of our eclectic usage of NULL strikes, while Caleb Rackliffe continues to work on CQL support for multi-partition transactions where, Josh McKenzie has indicated, the general sentiment is to go with “a SQL-congruent syntax."
Amit Pawar started a thread that’s generated a discussion on the potential benefits and shortcomings of a multi-threaded flushing CommitLog. Benchmarking complex features like this have proven difficult, and anyone with the knowledge of the subject is very welcome to contribute.
Andrés de la Peña has raised a question about inclusivity or exclusivity of token ranges, and API consistency came up because CASSANDRA-17575. You can follow and join in the discussion here.
Ekaterina Dimitrova continues to raise and resolve many of the questions about our properties, their units, and configuration parameters. This time the issue was the conversion of megabits and mebibytes producing double numbers, and how it should be handled in JMX/nodetool when reporting it to the users.
Henrik Ingo opened an email thread on the potential of developing a separate Apache Cassandra’s ecosystem site or revamping the existing Ecosystem section to potentially enable developers to maintain their own tool entries. You can join the conversation and get involved in collaborating here.
Speaking on the development of Backstage, the open platform for building developer portals, and work on Backstage Kubernetes in 2021:
“Spotify is mostly on GCP so our developers use a mix of Google managed storage products and self-managed ones. The managed storage solutions Spotify developers use are Cloud Bigtable, Cloud Spanner, CloudSQL, and Cloud Firestore. The unmanaged storage solutions Spotify devs start and operate themselves on GCE include Apache Cassandra, PostgreSQL, Memcached, Elastic Search, and Redis.”
Do you have a Cassandra case study to share? Email email@example.com.
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Cassandra Tutorials & More
Apache Cassandra Masterclass with Patrick McFadin (Video) - The Geek Narrator, Kaivalya Apte
Apache Cassandra vs. MongoDB Database — Which One’s for You? - Hassan Sherwani
Learn Apache Cassandra, a NoSQL Database - Beau Carnes
On the Blog
Apache Cassandra 4.1 Features: Pluggable Memtable Implementations - Branimir Lambov
Apache Cassandra Changelog #17 - Cassandra Community
Apache Cassandra 4.1: Configuration Standardization - Ekaterina Dimitrova