May 03, 2019 1:00 PM
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? ...
April 24, 2019 6:21 PM
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....
January 04, 2019 11:02 AM
The Linux AIO is designed for, well, Asynchronous disk IO! They are not network sockets, but is it possible to use Linux AIO API with network sockets? The answer is a strong YES! ...
November 29, 2018 9:54 AM
As TLS 1.3 was ratified earlier this year, I was recollecting how we got started with it here at Cloudflare. We made the decision to be early adopters of TLS 1.3 a little over two years ago. It was a very important decision, and we took it very seriously....
August 24, 2018 3:11 PM
Here at Cloudflare we use Prometheus to collect operational metrics. We run it on hundreds of servers and ingest millions of metrics per second to get insight into our network and provide the best possible service to our customers....
April 17, 2018 10:11 PM
In previous blog post we discussed how we use the TPROXY iptables module to power Cloudflare Spectrum. With TPROXY we solved a major technical issue on the server side, and we thought we might find another use for it on the client side of our product....
April 12, 2018 1:00 PM
Introducing Spectrum: a new Cloudflare feature that brings DDoS protection, load balancing, and content acceleration to any TCP-based protocol.Today we are releasing Spectrum. ...
February 20, 2018 7:49 PM
At Cloudflare we like Go. We use it in many in-house software projects as well as parts of bigger pipeline systems. But can we take Go to the next level and use it as a scripting language for our favourite operating system, Linux?...
October 23, 2017 11:28 PM
I have a weird setup. I type in Dvorak. But, when I hold ctrl or alt, my keyboard reverts to Qwerty. You see, the classic text-editing hotkeys, ctrl+Z, ctrl+X, ctrl+C, and ctrl+V are all located optimally for a Qwerty layout....
July 07, 2016 11:50 AM
A recent blog post posed the question Why do we use the Linux kernel's TCP stack?. It triggered a very interesting discussion on Hacker News....
April 05, 2016 12:05 PM
Back in November we wrote a blog post about one latency spike. Today I'd like to share a continuation of that story. As it turns out, the misconfigured rmem setting wasn't the only source of added latency. It looked like Mr Wolf hadn't finished his job....
December 17, 2015 2:15 PM
In a previous post we described our work on a new netmap mode called single-rx-queue. After submitting the pull request, the netmap maintainers told us that the patch was interesting, but they would prefer something more configurable instead of a tailored custom mode....
September 07, 2015 9:52 AM
In two previous posts we've discussed how to receive 1M UDP packets per second and how to reduce the round trip time. We did the experiments on Linux and the performance was very good considering it's a general purpose operating system....
June 16, 2015 1:47 PM
Last week during a casual conversation I overheard a colleague saying: "The Linux network stack is slow! You can't expect it to do more than 50 thousand packets per second per core!"...
May 11, 2015 10:08 AM
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?...
March 05, 2014 12:00 AM
Some interesting changes related to timekeeping in the upcoming Go 1.3 release inspired us to take a closer look at how Go programs keep time with the help of the Linux kernel. Timekeeping is a complex topic and determining the current time isn’t as simple as it might seem at fir...
October 03, 2013 5:00 AM
When building secure systems, having a source of random numbers is essential. Without them, most cryptographic systems break down and the privacy and authenticity of communications between two parties can be subverted....
