Architecture

Retiring snapshot-per-write for an event-fed read model TL;DR: Shakespeare succinctly describes what will follow, but our history storage mechanism was worse than O(N) — we were writing a whole copy of everything on every change. We moved to using events and an event-driven architecture. This is very much appreciated by our DB. Event-driven systems are an aggregation of the past — what’s past, is prologue! (The Tempest, Act II) I discuss this topic very briefly here as well (2018 video): https://youtu.be/-VJ6FtTS8zg ...

When Sara is taking her exam, the last thing she has on her mind is whether clicking “submit” will actually work. The exam ends: in the last two minutes of the window, most of the class hits submit at the same time. It’s not only the class — these are central exams, everyone in the country is submitting at the same time. When the system shows “Submitted”, this is a promise to Sara that her exam is now safely stored with it and she doesn’t need to worry. ...

SPS Nuremberg is one of the largest gatherings of the Industry. This year was no different. I was part of a team that presented the concept of OT/IT consolidation. I got quite a few comments and questions about the demo video (in Urdu here). So here’s a shot at answering some of the questions I got forwarded: The demo was (in oversimplified terms) showing PLC compute moved to software which can be orchestrated using Kubernetes. ...

So on my Clojurescript journey, the first roadblock I hit was corporate proxy. I don’t know why Java, maven, clojure (everybody?) doesn’t respect the environment variables but this is a real pain. Getting started Clojurescript is written in Clojure which requires Java. So we need to get all three up and running. Java To get Java JDK and JRE, run: $ sudo apt install openjdk-11-jre $ sudo apt install openjdk-11-jdk For proxy settings, edit /etc/java-11-openjdk/net.properties. ...

Evolvability of Architectural Styles… Big ball of mud Monoliths Event-driven architectures Service-oriented architectures (SOA) Serverless