Cloudflare Blog

An unexpected benefit of open-sourcing our code

Recently I was contacted by Dr. Igor Kozin from The Institute of Cancer Research in London. He asked about the optimal way to compile CloudFlare's open source fork of zlib.

CloudFlare enabling free SSL by mid-October

As of today, there are only about 2 million websites that support HTTPS. That's a shamefully low number. Two things are about to happen that we at CloudFlare are hopeful will begin to change that and make everyone love locks (at least on the web!).

Cloudflare is now powering Microsoft Edge Secure Network

This integration will allow Microsoft Edge users who opt in to browse the Internet more privately, without being tracked across websites

eBPF Can't Count?

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?

The next chapter for Cloudflare Workers: open-source

As the first announcement of Platform Week, today Cloudflare is announcing the open sourcing of the Workers runtime under the Apache-2.0 license

Europe's Internet resilience mitigates impact of submarine cable cuts

Two recent cable cuts that occurred in the Baltic Sea resulted in little-to-no observable impact to the affected countries, in large part because of the significant redundancy and resilience of Internet infrastructure in Europe.

Uganda's internet Shutdown

Two days ago, through its communications regulator, Uganda's government ordered the "Suspension Of The Operation Of Internet Gateways" hours before the country's general election. This action was confirmed by several users and journalists who got access to the letter sent to Internet providers.

Cloudflare automatically fixes Polyfill.io for free sites

polyfill.io, a popular JavaScript library service, can no longer be trusted and should be removed from websites

Fearless SSH: Short-lived certificates bring Zero Trust to infrastructure

Access for Infrastructure, BastionZero’s integration into Cloudflare One, will enable organizations to apply Zero Trust controls to their servers, databases, Kubernetes clusters, and more. Today we’re announcing short-lived SSH access as the first available feature of this integration.

CloudFlare “Interview Questions”

For quite some time we've been grilling our candidates about dirty corners of TCP/IP stack. Every engineer here must prove his/her comprehensive understanding of the full network stack. For example: what are the differences in checksumming algorithms between IPv4 and IPv6 stacks?

Recycling memory buffers in Go

This blog post is very old now. You probably don't want to use the techniques described here. GO'S sync.Pool is a better way to go.

We just shipped support for the ugliest part of HTTP: Vary

Vary support is now available in Cache Rules on every plan. You can normalize known negotiation headers, pass exact values through to the origin when those small differences matter, or bypass cache when the variation is too unpredictable.

Cloudflare to acquire Area 1 Security for $162M

Earlier today we announced that Cloudflare has agreed to acquire Area 1 Security

CloudFlare, PRISM, and Securing SSL Ciphers

Over the last week we've closely watched the disclosures about the alleged NSA PRISM program. At CloudFlare, we have never been approached to participate in PRISM or any other similar program.

How to escape the Linux networking stack

Many products at Cloudflare aren’t possible without pushing the limits of network hardware and software to deliver improved performance, increased efficiency, or novel capabilities such as soft-unicast, our method for sharing IP subnets across data centers. Happily, most people do not need to know the intricacies of…

Three Chapters at Cloudflare: Programmer to CTO to Board of Directors

Cloudflare mitigated yet another Okta compromise

On Wednesday, October 18, 2023, we discovered attacks on our system that we were able to trace back to Okta. We have verified that no Cloudflare customer information or systems were impacted by this event because of our rapid response.

D1: Improvements to performance and scalability

We've been heads down iterating on D1, and we've just shipped a major new version that's substantially faster, more reliable, and introduces Time Travel: the ability to restore a D1 database to any point in time.

Syria’s exam-related Internet shutdowns

To prevent cheating in exams many countries restrict or even shut down Internet access during critical exam hours. For most of June Syria is having planned Internet shutdowns during critical exam periods.

Setting Go variables from the outside

CloudFlare's DNS server, RRDNS, is written in Go and the DNS team used to generate a file called version.go in our Makefile. version.go looked something like this.

Universal DNSSEC: Secure DNS for Every Domain

CloudFlare launched just five years ago with the goal of building a better Internet. That’s why we are excited to announce that beginning today, anyone on CloudFlare can secure their traffic with DNSSEC in just one simple step.

Orchestrating AI code review at scale

Learn about how we built a CI-native AI code reviewer using OpenCode that helps our engineers ship better, safer code.

Filtering millions of packets per second on commodity NICs

In a previous post we discussed the performance limitations of the Linux kernel network stack. We detailed the available kernel bypass techniques allowing user space programs to receive packets with high throughput.

Broken packets: IP fragmentation is flawed

As opposed to the public telephone network, the internet has a Packet Switched design. But just how big can these packets be?

DNS LOC Record (2014)

One little used type of DNS record is the LOC (or location). It allows you to specify a physical location. CloudFlare handles millions of DNS records; of those just 743 are LOCs. Nevertheless, it's possible to set up a LOC record in the CloudFlare DNS editor.

Python Workers redux: fast cold starts, packages, and a uv-first workflow

Recent advancements in Cloudflare Python Workers means fast cold starts, comprehensive package support, and a great developer experience. We explain how they were achieved and show how Python can be used to build serverless applications on Cloudflare.

Cloudflare's Ethereum Gateway

Today, we are excited to announce Cloudflare's Ethereum Gateway, where you can interact with the Ethereum network without installing any software on your computer.

Introducing Pseudo IPv4

Today is June 6. For the last two years, the date has been celebrated as World IPv6 Day. CloudFlare has offered full IPv6 support as well as our IPv6-to-IPv4 gateway since 2012.

How to achieve low latency with 10Gbps Ethernet

In a recent blog post we explained how to tweak a simple UDP application to maximize throughput. This time we are going to optimize our UDP application for latency. Fighting with latency is a great excuse to discuss modern features of multiqueue NICs.

A Primer on Proxies

A technical dive into traditional TCP proxying over HTTP