OpenStack Flamingo

OpenStack has released its latest version: Flamingo (2025.2). While every release brings improvements, Flamingo stands out as a clear signal of where OpenStack is heading, and why that direction matters for organizations that rely on open infrastructure.

At Fairbanks and 42on, we see Flamingo as more than a version bump. It’s a milestone in OpenStack’s long-term evolution: toward performance, maintainability, and operational clarity.

One of the most impactful changes in Flamingo is the transition away from Eventlet, the legacy asynchronous framework that has powered OpenStack services for years. Eventlet has been both a workhorse and a bottleneck, difficult to maintain, inconsistent across components, and increasingly misaligned with Python’s modern async model.

By removing Eventlet, OpenStack is cleaning house. It’s replacing technical debt with native asyncio support and more predictable concurrency handling. The result: fewer scaling limitations, more stable operations, and code that’s easier to test and maintain over time.

This shift won’t happen overnight. Some components still rely on Eventlet for this release cycle, but Flamingo sets the stage for a full transition in the next release. For operators, this means fewer service quirks and more consistent behavior across the stack.

Flamingo also brings improvements across Nova, Neutron, and Cinder, all focused on reducing operational complexity:

• Nova (32.0.0) adds better resource tracking and scheduler efficiency, especially in large and mixed environments.
• Neutron (27.0.0) continues the clean-up of legacy agents and further stabilizes ML2 and OVN backends.
• Cinder (26.0.0) improves driver support for next-generation storage systems and faster backup/restore cycles.

These are not flashy updates, but they’re exactly what matters for production operators: predictable performance, faster recovery, fewer hidden dependencies.

With Flamingo, the OpenStack community continues its disciplined twice-a-year release cadence, ensuring stability without stagnation. The release schedule and component maturity make it clear: OpenStack is a long-term platform that evolves without breaking your existing infrastructure.

That’s why organizations across Europe keep investing in open infrastructure, and why we at Fairbanks and 42on help them adopt new releases safely, with minimal downtime and maximum continuity.

If you’re running an OpenStack environment today, Flamingo is your signal to start planning ahead. Eventlet deprecation, code modernization, and service optimizations will have real operational impact in the coming releases.

Now is the time to:

• Review your current architecture for dependencies that may rely on deprecated frameworks.
• Benchmark your environment’s performance before upgrading.
• Align your upgrade path with future releases like Gannet (2026.1), which will complete the Eventlet transition.

At Fairbanks and 42on, we support OpenStack users through the full lifecycle: from deployment and operations to upgrades, migrations, and managed services. With every release, we make sure your infrastructure remains not just functional, but future-ready.

OpenStack Flamingo is a release that looks forward, cleaner, faster, and built for the long game. The message is clear: open infrastructure is maturing, and those who keep up will stay in control.