Two months ago, I deleted my YouTube subscriptions. I now follow YouTube channels in my feed reader instead (I use the NetNewsWire app). How does that work? Is it better?| timotijhof.net
TL;DR: My updated take is Lockfiles for Node.js apps, not for other projects. When you run npm install, after you add or change a dependency in package.json, npm finds and selects the latest compatible version, downloads it, and replaces your package-lock.json file to describe what it found. The npm install command does not consider lockfiles…| Timo Tijhof
How does an open philosophy jive with best practices in performance and security? At Wikimedia, we’re selective in our dependencies and audit our own upstream sources. Progressive enhancement not only makes for a fast and accessible site, I argue it’s also the cheaper choice in the long run! Background The Wikimedia Foundation is the non-profit…| Timo Tijhof
For two years in 2020 and 2021, I shared Wikipedia’s worldwide browser statistics on Mastodon under #browserstats. They looked a little something like this: As the data includes the browser’s major version, I wondered whether I could use this to follow the adoption rate through each browser’s release cycle. The short answer is… Yes! Here…| Timo Tijhof
Deploying HTTP/2 support to the Wikimedia CDN significantly changed how browsers negotiate and transfer data during the page load process. We found regressions in performance during the transition and are sharing the lessons we learned. Hello, HTTP/2! In 2016, the Wikimedia Foundation deployed HTTP/2 (or “H2”) support to our CDN. At the time, we used…| Timo Tijhof
The Internet Archive discovers in real-time when WordPress blogs publish a new post, and when Wikipedia articles reference new sources. How does that work? Wikipedia Wikipedia, and its sister projects such as Wiktionary and Wikidata, run on the MediaWiki open-source software. One of its core features is “Recent changes”. This enables the Wikipedia community to…| Timo Tijhof
I miss the bygone era of very internety things, geocities-style scavenger hunts, easter eggs. So, I made thing. Hope you like it! → treasure21.timotijhof.net| Timo Tijhof
At Wikipedia, we built an efficient sampling profiler for PHP, and use it to instrument live requests. The trace logs and flame graphs are powered by a simple setup that involves only free open-source software, and runs at low infrastructure cost. I’d like to demonstrate that profiling doesn’t have to be expensive, and can even…| Timo Tijhof
Today, yours truly got to add his bit.| Timo Tijhof
What’s the deal with these string methods, and how are they different? String substr() str.substr(start[, length]) This method takes a start index, and optionally a number of characters to read from that start index with the default being to read until the end of the string. The start parameter may be a negative number, for…| Timo Tijhof
How a long sequence of dots allowed a regex to reach its internal stack limit. Premise Wikipedia’s production error logs were reporting an increase in app crashes from the search results page. The internal Logstash error report looked as follows: [RuntimeException] Cannot consume query at offset 0 (need to go to 7296) at mediawiki/…/CirrusSearch: QueryStringRegexParser->nextToken…| Timo Tijhof
Why does software accept invalid data? And, at what software layer should we reject it? Also, what are “namespaces” and “special pages” on Wikipedia? Premise One day, our server monitoring was reporting a high frequency of fatal errors from web servers. Over 10,000 an hour. The majority shared a single root cause – The program…| Timo Tijhof
These are short stories from bug hunts and incident investigations at Wikipedia. Impact After developers submit code to Gerrit, they eagerly await the result from Jenkins, an automated test runner. Every day during the 15 minute window before 5 PM in San Francisco, code changes submitted for code review would have mysteriously failing tests. Jenkins…| Timo Tijhof
These are short stories from bug hunts and incident investigations at Wikipedia. New database partition A user reported a timeout error for certain queries from the Public log viewer on commons.wikimedia.org. Database administrator Manuel Aróstegui investigated the underlying query and found that it was slow (and timing out) due to one of the database replicas…| Timo Tijhof
This week saw the conclusion of a project that I’ve been shepherding on and off since September of last year. The goal was for the initialisation of our asynchronous JavaScript pipeline (at the time, 36 kilobytes in size) to fit within a budget of 28 KB. The above graph shows the transfer size over time.…| Timo Tijhof
What’s the worst that could happen after npm install? When you open an app or execute a program from the terminal, that program can do anything that you can do. In a nutshell: Imagine if your computer were to disappear in front of your eyes and re-appear in front of mine. Still open. Still unlocked. What…| Timo Tijhof
Six years ago (in 2012), I was looking for a newsletter about browser releases. At the time, my motivation was to test and update the jQuery TestSwarm framework for each new browser release. I found a simple overview at browsehappy.com, by @WordPress. (1/) Lacking RSS, I decided to simply check it on a regular basis, and…| Timo Tijhof
This post shows how we measure and interpret load times on Wikipedia. It also explains what real-user metrics are, and how percentiles work. Navigation Timing When a browser loads a page, the page can include program code (JavaScript). This program will run inside the browser, alongside the page. This makes it possible for a page…| Timo Tijhof
Today, I’d like to challenge the assert.ok and assert.not* methods. I believe they may’ve become an anti-pattern. assert.ok Using assert.ok() indicates one of two problems: The former necessitates improvement to the code being tested. The latter comes with two additional caveats: Common examples: assert.not Using assert.not*() indicates one of three problems: Common example: I’ve yet…| Timo Tijhof
How did Apple create Safari, and what is PhantomJS? Safari In January 2003 Apple announced Safari, their new web browser for Mac. The Safari team had just spent 2002 building Safari atop KHTML and KJS, the KDE layout and javascript engines developed for Konqueror. The Safari team kept the codebase somewhat modular. This allowed Apple-branding…| Timo Tijhof
re·buke verb express sharp disapproval or criticism of (someone) because of their behavior or actions “she had rebuked him for drinking too much“ “the judge publicly rebuked the jury“ noun an expression of sharp disapproval or criticism “he hadn’t meant it as a rebuke, but Neil flinched“ (from the Oxford English Dictionary) I ran into the…| timotijhof.net
