Server Reliability: The Rule of Nines

After a little, er, let’s call it discussion I had with a certain supplier recently, I decided to write down a few words on server reliability and how to measure and understand it.

Like so many things that touch statistics it is very easy to take statements like “99.7% reliability” at face value without understanding its implications. Continue reading


I am a big fan of Draw with Jazza and follow his YouTube channel and I decided that I just have to take part in his November Challenge of the Month. The theme for this challenge was “Pokémon-Mashup”, that is, design a chimera of two or more different Pokémon. My idea was to create an amalgamation of the two Pokémon “Ninetails” and “Cubone”, wich resulted in me calling it “Ninebone”. Continue reading

A First Look at Swift: The Good, the Bad and the Ugly

SwiftLogoThis is a first look at Swift, Apple’s new programming language for MacOS and iOS development, which is still in Beta and thus by the time you are reading this, some of the bugs or features discussed here may have changed.

Also, while I have worked with a couple of programming languages over the years, I’m not really into all the latest academic hypes in language design. I’m only interested in one thing: is it fun to code in this language: can I solve problems in an efficient and elegant manner.

Having said this, it may not come as a surprise to you if I say that I never really got warm with Objective-C.

But let’s have a look at Swift now: Continue reading

Guitar Builder Project: “Blue Jay”

About a year ago I started to play guitar again. At that time I got myself a nice black Squier Deluxe Strat (named “Black Bess” by me), which is actually a good guitar for a very reasonable price.

Blue JayOf course, once you start with this, you also begin to have an eye on other types of electric guitars. Maybe a Telecaster as second guitar? Or a Les Paul? A semi-acoustic would also be nice…

Finally I bumped into a guitar builder forum and warmed up to the idea to actually try and build a guitar myself. Not a complete guitar build – that would be too much trouble without a proper, fully equipped workshop – but from a guitar build set. That would still leave enough challenges and learning opportunities to begin with. Continue reading

Media Centers: Raspberry Pi vs. Apple TV

It is hard to oversee the Raspberry Pi community’s enthusiasm for the XBMC media center software: no less than three software distributions are available and there are endless forums, tutorials.

No surprise then that I had to try some of them (and decided to stay with Raspbmc) and this became a permanent feature of my TV setup.

There is, however, also an Apple TV in our household, so this is a good opportunity for a feature and usability shootout.

Continue reading

A Raspberry Pi File and Print Server

I was recently looking into the options to buy a living room “home server” to centralize certain services like file and print server, media server, etc.

It didn’t take me long to realize that for less money I could get a whole legion of small microcomputers that do the same work better and more securely; and use less energy while doing so.

This was of course the pretext to buy my first Raspberry Pi. A few more should follow… This article starts a little series explaining what I did and how I did it. Today, I will look at the first and simplest type of server: Continue reading

Pocket Calculator

Here’s another weekend-project. Actually it’s more an “interface study”, but a fully functional calculator app. It is all based around the thought: why does the “Calculator” app on my computer still look like a hardware pocket calculator from the 1950’s?

  • Why doesn’t it render the formula like a proper formula editor?
  • Why can’t I enter formluae like in a modern programming language?

Continue reading