/techblog

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]

In the beginning of 2019 Oracle stopped releasing free-of-charge updates to their JDK, except for personal use. At the same time Oracle started requiring a subscription for Oracle JDK use in production environments. In this blog post we will look into OpenJDK as an alternative to the Oracle provided JDK and how one would migrate to it.

Now we continue improving the VPC template from my previous blog entry “Starting with Cloudformation templates”

What we ended up with there was a VPC with one subnet connected to the Internet. Or what is know in AWS lingo as a “Public Subnet”.

The goal now is a VPC with presence in tree Availability Zones with a “Public Subnet” in each, and a “Private Subnet” in each as well.

Humble beginnings

Before we go all out on tree ... [continue reading]

The number of great webservers on our toolbelt is constantly growing. From the venerable Apache httpd over lighttpd to nginx - and for the reverse proxy space pound, varnish and also nginx - the number just keeps growing. Caddy is a newcomer in this field, yet its features are already impressive. Lets take a brief look.

The plan

One of Redpill Linpro’s customers - had parts of their web presence managed by another provider - “P”. The customer wanted to migrate the server operations to Redpill Linpro (“RL”), including moving their Elasticsearch cluster to Redpill Linpro’s Elasticsearch offering, preferrably without downtime. While exporting and importing by using snapshots was an option, the better option would be a live migration.

A really useful Elasticsearch feature is the capability ... [continue reading]

As we saw in the introduction to ActiveMQ Artemis post, in ActiveMQ Artemis the implementation is separated from the configuration and data, requiring one to create a broker instance after installation of the implementation. One of the advantages of doing this, is that it makes upgrades much easier. Lets take a detailed look at that now.

Apache ActiveMQ is a modern, open source messaging platform. For years now, the community has been working on the successor to the venerable ActiveMQ - now sometimes referred to as ActiveMQ classic.

The new project is named ActiveMQ Artemis, at least until the time that it will be re-branded as ActiveMQ 6.0. Apparently that will happen once ActiveMQ Artemis has all features of ActiveMQ, but since no one knows if and when this feature parity is achieved lets take a look at ActiveMQ Artemis - the future of the ActiveMQ project.