How Netflix Powers the World’s Fastest Content Delivery Network with FreeBSD

When you stream your favorite Netflix show without buffering, you’re witnessing the power of FreeBSD in action. Behind the scenes of every seamless streaming experience lies one of the most impressive FreeBSD deployments in the world – Netflix’s Open Connect CDN, which delivers terabits of data per second to millions of viewers across 190+ countries.

The Challenge: Scaling to Global Proportions

Netflix faced a monumental challenge as streaming demand exploded globally. They needed an operating system that could handle massive traffic volumes while maintaining rock-solid stability and performance. The solution had to be flexible enough for extensive customization and optimization to meet Netflix’s unique operational requirements.

The stakes were high. As Gleb Smirnoff, Netflix’s skilled FreeBSD engineer, puts it: “We are one of the biggest sources of traffic on the internet – sending terabits per second, powered by thousands of servers or appliances, all running FreeBSD.”

The FreeBSD Solution: Why Open Source Won

Netflix didn’t just adopt FreeBSD – they embraced it completely. Starting with a proof-of-concept CDN built on FreeBSD 9.0-RELEASE in 2012, Netflix quickly realized that achieving their ambitious growth targets required pushing beyond standard operating system capabilities.

Here’s the key insight that changed everything: Netflix discovered that even a single percentage point increase in CDN performance translates to hundreds of thousands of dollars in savings. This made investing in FreeBSD’s ongoing development not just worthwhile, but essential.

The Bold Decision: Tracking FreeBSD-CURRENT

While many organizations play it safe with stable releases, Netflix made a counterintuitive choice that paid off massively. Drew Gallatin, a FreeBSD veteran with over 25 years of experience, explains their strategy:

“We decided what we were doing was silly, and what we should do is track FreeBSD-CURRENT. It sounds crazy because that’s where everybody pushes all their stuff, but it’s actually the best thing in the world for us.”

This approach allows Netflix to catch regressions immediately rather than discovering problems years later. As Gallatin notes: “When we run FreeBSD-CURRENT, we catch things really fast. If there’s some regression, we catch it right away.”

Performance Breakthroughs: What FreeBSD Enabled

Netflix’s FreeBSD implementation has achieved remarkable performance milestones:

400 Gb/s Throughput: Netflix operates the world’s first 100+ gigabit per second production CDN servers, achieving 375 Gb/s at 53% CPU utilization.

Kernel TLS Innovation: By moving TLS processing from user applications to the kernel, Netflix eliminated memory bandwidth bottlenecks and preserved the efficient sendfile pipeline. This breakthrough enabled their record-breaking throughput.

RACK TCP Stack: Netflix contributed to developing RACK (Recent ACKnowledgment), improving TCP performance and reliability for high-volume data transmission.

Asynchronous Sendfile: Netflix’s optimizations enable non-blocking data transfers that dramatically improve network throughput.

The Open Source Advantage: Community Collaboration

What sets Netflix apart isn’t just their technical achievements – it’s their commitment to the FreeBSD community. Rather than keeping their innovations proprietary, Netflix actively contributes improvements upstream.

Smirnoff emphasizes this philosophy: “It’s crucial to reduce the divergence of your operating system to FreeBSD, which means that you need to upstream your changes.”

This approach creates a virtuous cycle:

  • Netflix benefits from community development
  • The FreeBSD community gains battle-tested improvements
  • Everyone wins from enhanced performance and stability

Key community contributions include:

  • Kernel TLS implementation (collaboration with Chelsio and Mellanox)
  • Advanced VM page caching techniques
  • Performance optimizations tested at massive scale
  • Hardware acceleration support for various network cards

Why FreeBSD Was the Right Choice

Netflix’s success with FreeBSD demonstrates several key advantages of the operating system:

Scalability: Handles terabits per second of traffic across thousands of servers Performance: Enables record-breaking throughput with efficient resource utilization
Flexibility: Allows deep kernel-level customization and optimization Stability: Provides rock-solid reliability for mission-critical infrastructure Community: Benefits from active development and collaborative innovation Cost-Effectiveness: Open source licensing eliminates expensive per-server fees

Lessons for Your Organization

Netflix’s FreeBSD journey offers valuable insights for any organization considering FreeBSD:

Start Early: Engage with the FreeBSD community from the beginning to maximize benefits Test Rigorously: Implement comprehensive testing frameworks to catch issues quickly Contribute Back: Share improvements with the community to reduce technical debt Stay Current: Track recent developments to benefit from latest innovations Think Long-term: Strategic FreeBSD adoption pays dividends at scale

The Future is FreeBSD

Netflix’s success story is just the beginning. Their commitment to FreeBSD demonstrates that open source solutions can power the world’s most demanding applications. By choosing FreeBSD, Netflix didn’t just solve their CDN challenges – they helped advance the entire ecosystem.

As streaming continues to grow globally, Netflix’s FreeBSD-powered infrastructure stands ready to deliver. Every show you watch, every movie you stream, every seamless experience you enjoy is powered by the reliability, performance, and innovation that FreeBSD makes possible.

Ready to Experience FreeBSD’s Power?

Whether you’re building the next global CDN or optimizing your current infrastructure, FreeBSD offers the performance, stability, and community support to help you succeed. Netflix’s journey from a simple proof-of-concept to the world’s fastest CDN proves that FreeBSD scales with your ambitions.

Ready to get started? Download FreeBSD today and join the community that’s powering the future of high-performance computing.


The FreeBSD Foundation provides support for organizations adopting FreeBSD. Contact them for technical guidance, implementation assistance, and community connections that can accelerate your FreeBSD journey.

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