Technology

RRULE will make you hate calendars

Calendars are not the simplest applications by far. There are many different features, lots of different implementations, multitude of standards (just a few being RFC 2445, which was obsoleted by RFC 5545, which was updated by RFC 5546, RFC 6868, RFC 7529, RFC 7953, RFC 7986) , and plenty of other complexities.

One area in particular, which is cryptic and annoying is RRULE, or recurrence rule. You know, those events that don’t just happen once, but repeat once in a while. Starting with the most basic rules of repeating every day, and going into complete insanity of repeating every other Thursday, starting from next week and until the beginning of next year every other month, RRULEs can drive even the calmest of people completely insane. Here’s a screenshot to give you an idea.

Here are a couple of tools that we found useful, when implementing and testing this functionality:

rrule.js – a JavaScript library for working with RRULEs. See the demo here.
recurr – a PHP library for working with RRULEs.

nginx-module-vts – Nginx virtual host traffic status module

nginx-module-vts is a handy Nginx module for those who run complex Nginx configurations, with multiple servers, virtual hosts, caches, etc. Here’s an example partial screenshot of the output.

GitHub : Security Alerts and Team Discussions

GitHub blog recently announced a couple of interesting new features.

Firstly, Security Alerts. For now it only supports Ruby and JavaScript, but hopefully other languages are coming soon (PHP/Composer please!). Security Alerts will notify repository owners if there are any known security issues in any of the packages that the repository is using. Similar, I guess, to who SensioLabs Security Check works, but integrated with your GitHub.

Secondly, Team Discussions. This is yet another way place for the team to communicate. There are Issues and Pull Requests already. But those are more specific and more focused. For anything that doesn’t have a single issue, or doesn’t have a PR yet, a Team Discussion might be a better place.

ninja-mutex – Mutex implementation for PHP

ninja-mutex is a simple to use mutex implementation for php. It supports different adapters (flock, memcache, mysql, redis, …) so you can setup it as you wish. All adapters (if set up properly) can be used in multi server environment – in other words lock is shared between web servers.

All 500 of the World’s Top 500 Supercomputers Are Running Linux

Slashdot shares the story:

Linux rules supercomputing. This day has been coming since 1998, when Linux first appeared on the TOP500 Supercomputer list. Today, it finally happened: All 500 of the world’s fastest supercomputers are running Linux. The last two non-Linux systems, a pair of Chinese IBM POWER computers running AIX, dropped off the November 2017 TOP500 Supercomputer list. When the first TOP500 supercomputer list was compiled in June 1993, Linux was barely more than a toy. It hadn’t even adopted Tux as its mascot yet. It didn’t take long for Linux to start its march on supercomputing.

From when it first appeared on the TOP500 in 1998, Linux was on its way to the top. Before Linux took the lead, Unix was supercomputing’s top operating system. Since 2003, the TOP500 was on its way to Linux domination. By 2004, Linux had taken the lead for good. This happened for two reasons: First, since most of the world’s top supercomputers are research machines built for specialized tasks, each machine is a standalone project with unique characteristics and optimization requirements. To save costs, no one wants to develop a custom operating system for each of these systems. With Linux, however, research teams can easily modify and optimize Linux’s open-source code to their one-off designs.