March 20, 2023 1:00 PM
If I navigate to https://blog.cloudflare.com/, my browser will connect to a remote TCP address from the local IP address assigned to my machine, and a randomly chosen local TCP port. What happens if I then decide to head to another site?...
March 03, 2023 2:00 PM
Here at Cloudflare we run over 900 instances of Prometheus with a total of around 4.9 billion time series. Operating such a large Prometheus deployment doesn’t come without challenges . In this blog post we’ll cover some of the issues we hit and how we solved them...
January 16, 2023 1:46 PM
A race condition in the virtual ethernet driver of the Linux kernel led to occasional packet content corruptions, which resulted in unwanted packet drops by one of our DDoS mitigation systems. This blogpost describes the thought process and technique we used to debug this complex issue....
November 28, 2022 2:57 PM
Many leaks happen because of software bugs and security vulnerabilities. In this post we will learn how the Linux kernel can help protect cryptographic keys from a whole class of potential security vulnerabilities: memory access violations....
November 16, 2022 2:00 PM
Cloudflare now has OpenAPI Schemas available for the API. Users can use these schemas in any open source OpenAPI Tooling....
September 02, 2022 3:33 PM
When a request at Cloudflare throws an error, information gets logged in our requests_error pipeline. The error logs are used to help troubleshoot customer-specific or network-wide issues...
August 25, 2022 6:08 PM
We have amazing deep dives in our blog, but also research and how the Internet works kind of stories. Here are some highlights from 2022, and before (with glimpses of our history)....
July 18, 2022 12:56 PM
A crash in a development version of flowtrackd (the daemon that powers our Advanced TCP Protection) highlighted that libxdp (and specifically the AF_XDP part) was not Linux network namespace aware. ...
July 01, 2022 1:00 PM
In this post, we describe how we modified the Linux kernel to optimize for both low latency and high throughput concurrently...
June 29, 2022 11:45 AM
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...
June 28, 2022 12:57 PM
Hertzbleed is a brand-new family of side-channel attacks that monitors changes on CPU frequency...
June 24, 2022 1:45 PM
This blog offers Cloudflare’s perspective on how remote browser isolation can help organizations offload internal web application use cases currently secured by virtual desktop infrastructure (VDI)...
April 27, 2022 2:02 PM
Earlier this month, Cloudflare’s systems automatically detected and mitigated a 15.3 million request-per-second (rps) DDoS attack — one of the largest HTTPS DDoS attacks on record...
April 05, 2022 12:57 PM
This post tells the story of how a missing shell option called “pipefail” slowed Cloudflare down....
March 20, 2022 4:58 PM
We continue our technical deep dive into traditional TCP proxying over HTTP...
March 19, 2022 5:01 PM
A technical dive into traditional TCP proxying over HTTP...
February 04, 2022 1:58 PM
Chances are you might have heard of io_uring. It first appeared in Linux 5.1, back in 2019, and was advertised as the new API for asynchronous I/O. Its goal was to be an alternative to the deemed-to-be-broken-beyond-repair AIO, the “old” asynchronous I/O API...
February 02, 2022 9:53 AM
Often programmers have assumptions that turn out, to their surprise, to be invalid. From my experience this happens a lot. Every API, technology or system can be abused beyond its limits and break in a miserable way...
November 03, 2021 2:37 PM
It’s not every day that you get to debug what may well be a packet of death. It was certainly the first time for me. What do I mean by “a packet of death”? A software bug where the network stack crashes in reaction to a single received network packet, taking down the whole operat...
