The latest blog posts to take off on Hacker News. 4,389 posts.
My first computer was a BBC Micro. It could do basic graphics at a resolution of 640×256 - with 8 different colours. Not a typo. Eight! The mono speaker produced bleeps and bloops. It was basic, in all senses of the word. Eventually, talented hackers found a way for it to do simplistic 3D graphics and even speech…
Why does it take 2 years to realise that macOS has been checking signing certificate validity online?
This page describes a TCP performance problem resulting from a little-known interaction between Nagle’s Algorithm and Delayed ACK. At least, I believe it’s not well known: I haven’t seen it documented elsewhere, yet in the course of my career at Apple I have run into the performance problem it causes over and over…
Most PCs tend to boot from a primary media storage, be it a hard disk drive, or a solid-state drive, perhaps from a network, or – if all else fails – the USB stick or the boot DVD comes to the rescue… Fun, eh? Boring! Why don’t we try to boot from a record player for a change?
A lot of tech discussion these days is focused around scaling infrastructures to handle huge traffic. But it's important not to forget how far simple optimizations can go.
If you have followed Windows 10 at all during the last few years, you know that the Windows Subsystem for Linux, or WSL for short, is the hot topic among developers. You can finally run your Linux tooling on Windows as a first class citizen, which means you no longer have to learn PowerShell or, god forbid, suffer…
This is the story of the time I wrote some code, deployed it to production, and ended up bricking the server it was running on by frying the kernel. Beautiful rendition of me frying the kernel This post is about perils of concurrency and...
Achieving 100 Gbps intrusion prevention on a single server, Zhao et al., OSDI’20 Papers-we-love is hosting a mini-event this Wednesday (18th) where I’ll be leading a panel discussion including one …
“Computers are all made out of logic gates”. We’ve heard that saying before. We also have a sense that logic gates are very simple machines, analogous to light switches even. This raises the question: how exactly do kind-of-light-switches come together to form computers ? How does “storing a variable” or “calling a…
I booted the arm64e kernel of macOS 11.0.1 beta 1 kernel in QEMU up to launchd. It’s completely useless, but may be interesting if you’re wondering how an Apple Silicon Mac will boot.
NOTE: Currently this guide only deals with IPv4 as most people still don't use IPv6 and many ISPs also still only use IPv4, but IPv6 is planned for a future update of the guide.
For latency, anyway. A common architecture pattern is the “task queue”: tasks enter an ordered queue, workers pop tasks and process them. This pattern is used everywhere from distributed systems to thread pools. It applies just as well to human systems, like waiting in line at a supermarket or a bank. Task queues are…
These are my notes after learning the Paxos algorithm. The primary goal here is to sharpen my own understanding of the algorithm, but maybe someone will find this explanation of Paxos useful! This post assumes fluency with mathematical notation.
Today Raspberry Pi Trading announced the Raspberry Pi 400, the latest in the series of small education-focused computers that started with the original Raspberry Pi in 2012. For years, people have come up with creative ways to hack a Pi into keyboards, like the Original Pi in an old Mitsumi keyboard, or the Pi 3 A+ in…
Yesterday, I read a phenomenal paper on how disruption free release at Facebook.
Some recent backtracking from what we have been calling "Microservices" has sparked anew the debate around that software architecture pattern. It turns out that for increasingly more software people, …
TLA+ is a formal specification language that you can use to verify programs. It’s different from other formal verification systems in that it’s very pragmatic. Instead of writing proofs…
A complete guide to the structure and layout of APFS startup disks from High Sierra to Big Sur (Intel), together with tear-out PDF charts.
Executables have been fascinating to me ever since I discovered, as a kid, that they were just files. If you renamed a .exe to something else, you could open it in notepad! And if you renamed somet...
There's been some recent discussion about whether the X server is abandonware. As the person arguably most responsible for its care and feed...
In the field of computer science, the Paxos algorithm is notorious for how difficult it is to understand. I had to learn the Paxos algorithm in my distributed systems class. I even have "implemented" it by translating Leslie Lamport's TLA+ to Python. But I didn't understand it until much much later.
