Skip to content

Category: Computer Science

When you commit to git, how long does it matter?

Commit to git

Erik Bernhardsson has been running Big Data on Git repositories of various kinds.

He was trying to find out what the half-life of code is. That is, when you commit to a repository, your code becomes part of a project, but eventually other code will replace it and it will no longer be part of the current version. How stable is the codebase, what is the half-life of code? And why is it different in different projects?

As a project evolves, does the new code just add on top of the old code? Or does it replace the old code slowly over time? In order to understand this, I built a little thing to analyze Git projects, with help from the formidable GitPython project. The idea is to go back in history historical and run a git blame […]

1 Comment

Magic circles banning autonomous cars

Trapping Autonomous Cars

Somebody sent me a link to Vice withe the comment “A multiple hit in the Venn Diagram of your interests”.

It’s about an artist using technology disguised as ritual magic to trap self-driving cars (and similar shenanigans). The assessent was correct, this is beautiful.

The image from the article shown above shows a self-driving car inside fake street markings. The broken lines allow the cars logic to enter the circle, the unbroken linkes mark a demarcation that must not be crossed, hence the car can never leave.

It ties back to a story my driving instructor told me. He was making a point about “How things are being presented matters”, relating about a beginners driver who had been told to imagine unbroken lines as a “wall that cannot be crossed” and who because of that had problems – sometimes rules must be broken to preserve their meaning and spirit.

 

2 Comments

Netways OSDC 2017: Something Openshift Kubernetes Containers

OSDC 2017 Registration
I will be speaking at the Netways Open Source Data Center Conference, which is in Berlin between May 16 and 18.

At work, we are currently busy loading our first two Kubernetes Clusters (Openshift actually) with workloads.

What exactly will be in the slides I do not know, yet, but it will be about our journey at Booking, the transition from automated baremetal provisioning of rather monolithic applications to a more containerized setup and the changes and challenges this brings. It will be very much a snapshot of the state of things at that point in time, and our learnings and perspective then.

Leave a Comment

MySQL and encrypted connections

2006 slides by Rasmus Lerdorf

Since 5.0, MySQL does allow natively encrypted connections to the database, and supposedly also does support client certs for user authentication. Supposedly, because I never tried.

MySQL as a database performs well with transient connections as they are prevalent in two-tier deployments (mod_php, mod_perl, mod_python to database), in which a database connection is made upon web request, and the connection is torn down at the end of the request. This model does not scale so well with encryption in the mix, as on connection a full TLS/SSL exchange must be made.

2 Comments

Docker Image Vulnerability Research

federacy reports “24% of the latest Docker images have significant vulnerabilities“.

The Report underlines the importance of running your own image building service and your own local registry when deploying Docker and Kubernetes.

And that includes the base operating system images, because the test above focused on latest images of official docker images of base operating system images, and known vulnerabilities in it. It lists last years vulnerabilities still being present in current images.

Leave a Comment

Kamergotchi

Leider endet das Spiel morgen: In Kamergotchi muß der spielende Niederländer seinen Abgeordneten am Leben halten.

Kamergotchi, het ideale spel voor de betrokken kiezer. Hou je lijsttrekker zo lang mogelijk in leven door hem eten, aandacht of kennis te geven. Zoveel politieke invloed had je nog nooit!

Leave a Comment

B.boring

Some time ago, I gave a talk about boring technology at Booking, which means choosing the simplest, stable and maintainable solution you can get away with for solving a problem at a given scale.

Apparently Dan McKinley has similar views, which he explained in Choose Boring Technology. The writeup explains nicely what boring technology is, and why to prefer this.

Never forget your mission, which is business, not technology. The technology is a necessary tool, but likely not your friend.

Leave a Comment

A book on systemd, that’s what’s missing

Two years ago, I ranted on Google plus that there still is no book on systemd (actually, on systemd + journald + cgroups/namespaces and the assorted things that come with it if you are doing it right).

There are writeups such as various Getting Started articles, and there is collections to the writeups on PID Eins, but there is no book.

A book would be good, though, because it should contain stuff like this.

9 Comments