Altinity in Action: A Report from FOSDEM ’25
FOSDEM is one of the most important and influential conferences in the world of open source. At last month’s FOSDEM ’25, Altinity had a significant presence, with multiple presentations and attendees. Here’s a wrap up of what we did at the show, along with observations by some of our speakers.
Altinity presentations
Altinity speakers gave presentations on a wide range of technical and community topics, showcasing our work in the ClickHouse® community as well as the passion we have for various open-source projects. Throughout the conference, we gave presentations on:
- Open source business models that let you keep your soul
- Open Telemetry, showing how ClickHouse is a great database for consolidating telemetry data
- How to use combinatorics and behavioral models to test the multiple authentication methods feature in ClickHouse
- The internals of a cloud-native database (in an amazing coincidence, that database happens to be ClickHouse)
- How to add vector searches to MySQL
- Nix and NixOS
If you missed these sessions (or the conference itself), worry not; we’ve got summaries of those talks, along with videos and slides. Read on!
Build a Great Business on Open Source without Selling Your Soul
Robert Hodges
A profitable business is one of the best protections for commercial open source projects and communities that depend on them. Robert’s talk looks at the experience of companies that pulled it off and explains how to do it for your own projects.
Robert covers soul-preserving approaches to the crucial issues that every open source business faces:
- Commercial models that actually work
- Giving back to the community
- Gracefully collecting money for free software
- Working with (or even creating) foundations
- Taking VC funding
It is possible to balance a strong belief in open source communities with making payroll every two weeks. We’ve done it here at Altinity and others have, too; watch this video to hear Robert share our secrets.
O11y-in-One: Exploring a Unified Telemetry Database
Josh Lee
OpenTelemetry is often introduced as a way to send your metrics, traces, and logs to separate backend databases. But in reality, most organizations juggle at least half a dozen monitoring tools in production. What we really need isn’t just a standardized way to collect telemetry—it’s a unified datastore that brings all the backends together, much like how OpenTelemetry has unified telemetry collection.
Could ClickHouse be that solution? [Spoiler alert: Yes.] In this talk, Josh looks at the fundamentals of telemetry and explores what we truly need from a unified telemetry datastore. ClickHouse has features that make it an exceptional choice for tracing and logs today—and has growing potential for time-series data in the future.
Other topics Josh covers include the seamless integrations between ClickHouse and open-source tools like OpenTelemetry, Prometheus, Grafana, and Kafka; all of these technologies work together to enhance observability pipelines. Looking towards the future, Josh looks at cutting-edge, open-source observability platforms built on ClickHouse, including CoRoot, and QRYN.
ClickHouse can be a core part of your telemetry infrastructure. Josh’s presentation shows you what’s possible now and what’s emerging in the broader ClickHouse community.
Testing Support for Multiple Authentication Methods in ClickHouse Using Combinatorics and Behavioral Models
Alsu Giliazova
Alsu gave a talk about testing the support for multiple authentication methods in ClickHouse using combinatorics and behavior modeling. Since this is an RBAC feature, it needs to be tested thoroughly and properly. That’s why a combinatorial approach, with a predefined set of expected outcomes for each combination, is a great choice. Alsu explains how we applied these techniques to test the feature.
We would be remiss if we didn’t give a shout-out to the eminently talented Arthur Passos, who developed the multiple authentication methods feature. If you’d like to learn more, Arthur’s blog post on how this powerful new capability works is a great overview.
Tracing the Internals of a Cloud-Native Database
Josh Lee
Have you ever wondered what happens inside a distributed database when you run a query? In this talk, Josh explores the inner workings of ClickHouse using OpenTelemetry-compatible distributed tracing to analyze the internal workings of various ClickHouse clusters while we run a variety of queries. Perfect for database enthusiasts and cloud-native developers, this session offers practical insights into tracing tools and query optimization in distributed systems.
Boosting MySQL with Vector Search: Introducing the MyVector Plugin
Alkin Tezuysal and Shankar Iyer
As the demand for vector databases and Generative AI continues to rise, integrating vector storage and search capabilities into traditional databases has become increasingly important. In this session, Alkin and Shankar introduce the MyVector Plugin, a project that brings native vector storage and similarity search to MySQL.
Unlike PostgreSQL, which offers interfaces for adding new data types and index methods, MySQL lacks such extensibility. However, by utilizing MySQL’s server component plugin and UDF, the MyVector Plugin successfully adds a fully functional vector search feature within the existing MySQL + InnoDB infrastructure, eliminating the need for a separate vector database.
The session explains the technical aspects of integrating vector support into MySQL, the challenges posed by its architecture, and real-world use cases that showcase the advantages of combining vector search with MySQL’s robust features.
If you’re looking to take your MySQL knowledge into the world of vector databases and generative AI, this talk is a great place to start.
My Nix-Powered Homelab
Josh Lee
For Josh, Nix-the-package manager has replaced homebrew, ASDF, and even docker. But its potential goes far beyond managing development environments. With its declarative, reproducible configurations, Nix is also an excellent choice for managing entire servers.
In this talk, Josh showed how he uses NixOS and nixos-generators to create both stable and ephemeral VMs on his Proxmox hypervisor hosts, and how he runs services like Grafana, Docker, Tailscale, and more.
From there, Josh went on to cover how to deploy and update Proxmox VMs remotely using Nix, set up a WireGuard router with NixOS, and deploy services directly to NixOS declaratively. And how to deploy Docker services to NixOS, using the same object tree and code files as all of your other configurations.
Whether you’re managing a homelab or building out larger infrastructure, check out the video and slides to see how Nix can transform your approach to system configuration and service deployment.
Thoughts on the show
Alsu Giliazova
The talk went really well, even though I was extremely nervous, as it was my first time speaking at a conference. The audience was incredibly supportive, and I received some really interesting questions and positive feedback afterward. My colleagues were also amazing, offering their support before, during, and after the presentation. I’m truly grateful to work with such kind people.
Josh Lee
This was my first FOSDEM, and it was unlike any other conference I’ve experienced (when many of them are largely the same). It seemed as if unofficially there were only two rules: must love open source; and respect the fire code. Other than that, the conference was open to attend without badges or registration.
The huge number of devrooms meant that at any given moment there were at least two or three talks I felt bad about missing. The huge number of patrons meant that it was hard to get into many of the most popular talks – including Robert’s “How to build a great business on open source without selling your soul” – although the recording was excellent.
I had the honor of speaking in three devrooms: Cloud Native Databases, Monitoring & Observability, and Nix & Nix OS – some of my favorite topics, and a testament to the fact that FOSDEM has something for everyone (as long as you love open source software).
I’m a bit odd in that I *love* booth duty, but working at the OSACOM booth at FOSDEM was truly the best. We weren’t there to sell. The other attendees weren’t there to buy. They may have come to our booth for the stickers, but they stayed for engaging conversations about open source software and our K3s demo cluster on Raspberry Pis.
Alkin Tezuysal
This year was one of my busiest in the past decade, packed with meaningful discussions, engaging sessions, and reconnecting with the vibrant open-source database community.
I had the privilege of serving on the MySQL Devroom Committee, where we curated an outstanding lineup of talks, and I also delivered my own MySQL Devroom talk, sharing insights with a passionate audience.
Hosting the Open Source Analytics Community Table was another highlight—seeing the enthusiasm for open-source analytics and engaging with like-minded professionals reinforced how much this space continues to evolve.
The O’Reilly MySQL Cookbook (4th Edition) book signing was a fantastic opportunity to meet readers and discuss real-world MySQL challenges and solutions. On top of that, I attended six excellent sessions from Altinity, Inc., each showcasing innovative developments in analytics and database performance.
Beyond the scheduled sessions, the true magic of FOSDEM happens in the hallways, over coffee, and in those impromptu discussions that spark new ideas. Meeting open-source database alumni, longtime colleagues, and new faces was a personal highlight. The sense of camaraderie and shared purpose in the open-source community is what makes these events so special.
A huge shoutout to Frederic Descamps, the Oracle MySQL teams, and everyone involved in organizing the PreFOSDEM MySQL Days and bringing back the MySQL Devroom—your hard work and dedication made this a resounding success. There are far too many people to name individually, but I deeply appreciate every conversation, collaboration, and shared moment.
And of course, a very special Happy 30th Birthday to MySQL! 🎉 Here’s to three decades of innovation, community-driven progress, and an exciting future ahead. Looking forward to many more years of open-source excellence!
P.S. This year was also FOSDEM’s 25th anniversary.
ClickHouse® is a registered trademark of ClickHouse, Inc.; Altinity is not affiliated with or associated with ClickHouse, Inc.