How YouPorn Uses Redis: SFW Edition

“I interviewed Eric Pickup, IT Lead at the Manwin group (the company behind sites like YouPorn and Pornhub), to tell us about their transition to using Redis, why they made the switch, and how well it’s worked. Check out Eric’s presentation on Building a Website to Scale, or get started with your own free Redis instance…”

Introducing the Go Race Detector

“Race conditions are among the most insidious and elusive programming errors. They typically cause erratic and mysterious failures, often long after the code has been deployed to production. While Go’s concurrency mechanisms make it easy to write clean concurrent code, they don’t prevent race conditions. Care, diligence, and testing are required. And tools can help.

We’re happy to announce that Go 1.1 includes a race detector, a new tool for finding race conditions in Go code. It is currently available for Linux, OS X, and Windows systems with 64-bit x86 processors.

The race detector is based on the C/C++ ThreadSanitizer runtime library, which has been used to detect many errors in Google’s internal code base and in Chromium. The technology was integrated with Go in September 2012; since then it has detected 42 races in the standard library. It is now part of our continuous build process, where it continues to catch race conditions as they arise…”

The Lisp Bookshelf

“So I’ve obviously been paying a lot of attention to this site lately… so much so that I’m thinking of some sort of excuse for explaining the absence of decent reading material.

Jokes aside, I’ve recently gone through spells of intense study and absolute laziness. However, I have come across a gem of a website that has inspired this post, Programming-Musings by Jose Antonio Ortega Ruiz (Jao).

Jao is mainly a Scheme hacker and is the author of the well-known Geiser project, an interactive environment for Scheme in Emacs. I found his website by accident through a post in Hacker News, and read his post A Scheme Bookshelf which detailed his road to Scheme mastery.

I’ve been thinking of writing a similar post on my own study path of Common Lisp and reading his account finally made me decide to get on with it…”

Lifetimes of cryptographic hash functions

“Quick summary of my recommendations on compare-by-hash: If you are using compare-by-hash to generate addresses for data that can be supplied by malicious users, you should have a plan to migrate to a new hash every few years. For example, BitTorrent falls into this category, but rsync doesn’t. Keep in mind that new, more secure hashes are likely to have larger outputs (e.g., 256 bits for SHA-2 vs. 160 bits for SHA-1) and be more computationally expensive…”

Learn #Emacs Lisp in 15 minutes

“I was surprised not to find an introduction to Emacs Lisp on so I created one. I sent a pull request to the github repository, hopefully this will be merged at some point.

In the meantime, comments and feedback are very welcome.

Thanks to @squintar who kept encouraging me to write this for her own needs. Enjoy!…”

The 10 Hardest Logic Puzzles Ever Created

“So you think you are clever, right? Then here is your chance to pit your brain against some of the world’s hardest logic puzzles ever created. After having created number puzzles like Calcudoku and Killer Sudoku for many years, I decided to try and find the most challenging ones out there. Every once in a while I added a new type of puzzle, until I ended up with a list of 10.

In the following list you will find both familiar puzzles and games such as Sudoku and Calcudoku as well as lesser known ones such as the Bongard Problem and Fill-a-Pix. Some of these puzzles can be solved right on this page while others can be downloaded or reached elsewhere. All of them, however, are promised to test your solving skills to the absolute limit and keep you busy for hours, if not days…”

Probablistic Programming & Bayesian Methods for Hackers

“The Bayesian method is the natural approach to inference, yet it is hidden from readers behind chapters of slow, mathematical analysis. The typical text on Bayesian inference involves two to three chapters on probability theory, then enters what Bayesian inference is. Unfortunately, due to mathematical intractability of most Bayesian models, the reader is only shown simple, artificial examples. This can leave the user with a so-what feeling about Bayesian inference. In fact, this was the author’s own prior opinion…”