Programming

84 million requests a second means even rare bugs appear often. We'll reveal how we discovered a race condition in the Go arm64 compiler and got it fixed.

Thea Heinen

udpgrm is a lightweight daemon for graceful restarts of UDP servers. It leverages SO_REUSEPORT and eBPF to route new and existing flows to the correct server instance.

Marek Majkowski

The initial posts are dedicated to the x86 architecture. Since then, the fleet of our working machines has expanded to include a large and growing number of ARM CPUs. This time we’ll repeat this exercise for the aarch64 architecture.

Oxana Kharitonova

Learn how to patch Linux security vulnerabilities without rebooting the hardware and how to tighten the security of your Linux operating system with eBPF Linux Security Module

Frederick Lawler

Continue learning how to import and execute code from an object file. In this part we will handle external library dependencies.

Ignat Korchagin

Is it ok to have if clauses that will basically never be run? Surely, there must be some performance cost to that...

Marek Majkowski

Continue learning how to import and execute code from an object file. This time we will investigate ELF relocations.

Ignat Korchagin

Ever wondered if it is possible to execute an object file without linking? Or use any object file as a library? Follow along to learn how to decompose an object file and import code from it along the way.

Ignat Korchagin

A few months ago, after reading about Cloudflare doubling its intern class, I quickly dusted off my CV and applied for an internship. Long story short: now, a couple of months later, I found myself staring at Linux kernel code and adding a pretty cool feature to gVisor.

Lennart Espe

SYN-cookies help mitigating SYN-floods for TCP, but how can we protect services from similar attacks that use UDP? We designed an algorithm and a library to fill this gap, and it’s open source!

Jonas Otten

Last month finally I had an opportunity to use Bloom filters. I became fascinated with the promise of this data structure, but I quickly realized it had some drawbacks. This blog post is the tale of my brief love affair with Bloom filters.

Marek Majkowski

Cloudflare is organizing a meetup in Seattle on Tuesday, June 25th and we hope you can join. We’ll be bringing together members of the developers community and Cloudflare users for an evening of discussion about serverless compute and the infinite number of use cases for deploying code at the edge.

Giuliana DeAngelis

Generating random outcomes is an essential part of everyday life; from lottery drawings and constructing competitions, to performing deep cryptographic computations.

Alex Davidson

In this tutorial, we’ll build a todo list application in HTML, CSS and JavaScript, with a twist: all the data should be stored inside of the newly-launched Workers KV, and the application itself should be served directly from Cloudflare’s edge network, using Cloudflare Workers.

Kristian Freeman

Today, we’re excited to announce Workers KV is entering general availability and is ready for production use!

Ashcon Partovi

Recently at I gave a short talk titled "Linux at Cloudflare". The talk ended up being mostly about BPF. It seems, no matter the question - BPF is the answer. Here is a transcript of a slightly adjusted version of that talk.

Marek Majkowski

It is unlikely we can tell you anything new about the extended Berkeley Packet Filter, eBPF for short, if you've read all the great man pages, docs, guides, and some of our blogs out there. But we can tell you a war story, who doesn't like those?

Jakub Sitnicki

Our servers manage heaps of network packets, from legit traffic to big DDoS attacks. For top efficiency, we adopted eXpress Data Path (XDP), a Linux kernel tool for swift, low-level packet handling.

Arthur Fabre