The Giftcard-demo demonstrates Axon Commands, Events and Queries either together or in a distributed fashion. Now with the tracing extension, these messages and context information can be visualised to get insight into the application behaviour. Requirements to run the demo You will need git, docker and maven. We will checkout out the code, build the […]
Centralized metrics with Stackdriver Prometheus Exporter
Google does not currently charge for monitoring data when it comes to GCP metrics. Therefore, if you want to monitor operations of Google Cloud Platform (GCP) services, such as: Compute Engine, Cloud SQL, Cloud Dataflow and Cloud Pub/Sub, using Google’s Cloud Monitoring service – Stackdriver – is a perfect choice…
Dockerising your legacy integration tests
As most of you will know, every now and then you can expect the question ‘Can you help fix something on this ancient project?’ According to the Universal Software Ageing table, that means anything from last month to much, much older. I got such a question recently, being in-between projects, and this project fell squarely into […]
Spring Data Native Queries and Projections in Kotlin
This blog describes the solution to mapping native queries to objects. This is useful because sometimes you want to use a feature of the underlying database implementation (such as PostgreSQL) that is not part of the JPQL standard. By the end of this blog you should be able to confidently use native queries and use […]
Refactoring from Elasticsearch version 1 with Java Transport client to version 6 with High Level REST client
Every long running project accrues technical debt. It may be that the requirements today have evolved in a different direction from what was foreseen when the project was designed, or it may be that difficult infrastructure tasks have been put off in favor of new functionality. From time to time, you need to refactor your […]
How to send your Spring Batch Job log messages to a separate file
In one of my current projects we’re developing a web application which also has a couple of dozen batch jobs that perform all sort of tasks at particular times. These jobs produce quite a bit of logging output when they’re run, which is important to see what has happened during a job exactly. What we […]
Collecting data from a private LoRaWAN sensor network into Elastic
Introduction to LoRaWAN and ELK Why LoRaWAN, and what makes it different from other types of low power consumption, high range wireless protocols like ZigBee, Z-Wave, etc … ? LoRa is a wireless modulation for long-range, low-power, low-data-rate applications developed by Semtech. The main features of this technology are the big amount of devices that […]
From The Trenches: LoRa, LoRaWAN tutorial with the LoRaBee
Once in a while you stumble across an interesting technology which is an enabler of new solutions, and new business cases. At Trifork Eindhoven we believe LoRa / LoRaWan might be such a technology. We are currently working on several Internet of Things solutions which could directly benefit from long distance communication, with a low energy […]
Spring-AMQP and payload validation: some notes from the trenches
It’s been a while since I’ve written one of our from-the-trenches blogs: that’s mostly because I’ve been very busy in those trenches developing systems for our customers. This week I completed a Spring Boot-based microservice which is responsible for interacting with some 3rd party SOAP service: its own clients communicate with it by sending request […]
City-wide crowd management in Amsterdam
As most residents and visitors of Amsterdam know, every year more people are visiting Amsterdam, city wide events like GayPride, Koningsdag and MuseumNacht are getting bigger and more frequent, putting more strain on the city’s infrastructure and all people living in the city center. That’s why this November 7th, Amsterdam Marketing organized the Museumn8 hackathon […]