/techblog

Pipewire, the new default audio subsystem in Fedora 34, introduces support for the mSBC audio codec for the Bluetooth Headset Profile (HSP), which is used for transmitting bi-directional audio to/from Bluetooth headsets. The mSBC codec provides greatly improved audio quality over the CVSD, the default codec used with HSP. If you are using a Bluetooth headset to participate in teleconferences, you will most definitively want to use mSBC if your headset supports it. Your colleagues will sound better ... [continue reading]

GraphQL is a modern approach to APIs that simplifies integrations. This is an introduction to what GraphQL is, and we build a simple GraphQL service with the help of Vert.X.

What you’ll need to follow along

This introduction will barely scratch the surface of the potential and power that GraphQL together with Vert.X offers. Understanding of programming and the REST protocol is assumed.

Make sure to have the following installed:

• JDK 8+
• Maven
• IDE

Source code for ... [continue reading]

Getting a single random row, or a few rows, from a table in order to get representative data for example is a frequent need. The most common way to do this in PostgreSQL is using ORDER BY random() like:

SELECT id FROM data ORDER BY random() LIMIT 1 

But when run on a large table this can be very slow. Jonathan Katz mentioned a ... [continue reading]

As mentioned in my previous post, we have some interesting projects involving Hyper-V. One of them being a way to automatically verify that our Windows server backups are functional.

This post is about how we’ve set that up.

TLDR: check the script on github

Windows backup on OpenStack

Our main virtualization platform is OpenStack, which is awesome. And while we try to mostly utilize open-source solutions, there are times when that’s just not the best way to ... [continue reading]

TLDR: Jump to the end for the XML tags we found necessary to get this working.

We have a few projects coming up where we for different and exciting reasons need to use Hyper-V. But running Hyper-V on bare-metal would in this case take up more resources than reasonable for us, so we’re nesting it inside one of our kvm clusters.

But getting Hyper-V 2019 to actually run steadily using nested virtualization inside of qemu-kvm provided some challenges that turned ... [continue reading]

I want to wrap up the VPC template from the previous blog entry “Moving forward with Cloudformation templates”

What we ended up with there was a VPC with a Private and a Public Subnet in 3 Availability Zones.

Now I want to start to use the Outputs section of the template.

And when that has been introduced, I want to use Nested Stacks

Why Outputs?

When we create a VPC with the template from the last ... [continue reading]

Clojure is a really nice, dynamic programming language on the Java virtual machine. It gives you the expressivity of a lisp, full interop with the whole Java/Kotlin/Scala ecosystem of libraries, a battle-hardened VM, and it’s elegant.

The downside is that it runs on the JVM and has to pay a heavy cold start penalty. We can fix that, using GraalVM, and have our cake, eat it, and space-time fold it too.

We will be using a few containers, podman and GraalVM’s native-image ... [continue reading]

Contributing to Free Software using Open Source methodics may look like intimidating deep expert work. But it doesn’t have to be that. Most Free Software communities are friendly to newcomers, and welcome all kind of contributions

There are many steps to take on the path to automation. Some are easier, some not so much.

One less popular step is documentation. Yes - the documentation you haven’t written. You know what I mean.

No matter how well written your code is, there usually is a gap between today’s YOU and the future YOU, who has to work with and pick up what you leave behind.

This is usually also the reason for writing the documentation last. Better ... [continue reading]

All our customers have an online presence. A subset of these have higher demands when it comes to latency and reliability than others. Sometimes this is purely because of high amount of real end-user traffic - and sometimes it’s more malicious; A DDOS-attack.

In most OpenStack-configurations, you have the concept of «port security». This is a firewall enforced on the network interface of the virtual instance. It is also there to prevent a malicious self-service user from spoofing their IP ... [continue reading]