Posts

Elastic stack: a renewed introduction

A few years ago, I had an assignment at my former client involving Elasticsearch, Logstash and Kibana to build an operational dashboard. It was fun to do and very instructive; afterwards, I wrote an article about my experiences and spoke at various conferences. Recently, I was asked by another team in my company to assist them in setting it up for their team. A good chance to catch up with some old friends, and see how they have changed over the years.

Verify logging with Logback

Sometimes you have a piece of logging that is very important, maybe even part of a business requirement. In that case, you might want to verify that in a unit test, so you can rest assured that this requirement is actually met. How to do that? Mock it away A first approach might be to just mock your logging framework in a unit test and verify it was called as you expected.

Blah blah Microservices blah blah

As a closing keynote on the second day of Jfokus, Jonas Bonér took the stage under the very clarifying title “Blah blah Microservices blah blah”, which turned out to mean “From microliths to microsystems”. As a first observation, he stated that no-one really likes microservices. They are kind of a necessary evil - because “doing” microservices comes at a cost. In fact, microservices are just a specialisation of an older concept called distributed systems.

Jfokus, Day 2

The second day of Jfokus is just as action-packed as the first one. However, part of the action is me giving two talks. Both of them scheduled today, so a little less time for attending other sessions and blogging about them. I did attend some other sessions after lunch time, on which I’ll report below. Introduction to Machine Learning Directly after the lunch, James Ward gave an introduction to machine learning.

Quickly switch Java versions on macOS

Inspired by a Jfokus session I attended today I decided to download and install a preview of Java 9 on my MacBook. That went pretty quick and without much trouble. But when I issued java -version on my terminal, I was greeted with Java(TM) SE Runtime Environment (build 9-ea+155) Java HotSpot(TM) 64-Bit Server VM (build 9-ea+155, mixed mode) Although that’s nice - you’d even expect it, maybe - I realised I often need Java 8 as well.

Jfokus, Day 1

These days, I’m in Stockholm, attending and speaking at the Jfokus conference. Yesterday night was a great opportunity to get to know a few other speakers during dinner. We were even surprised by an act of the Lemon Squeezy barbershop quartet singing for us - very beautiful! But today, the serious stuff started. In the following sections, I have written down my notes and observations of each of the sessions I attended.

Long time, no blog

Recently, I was asked to write a blog about a side project I did. That question reminded me of the blog I used to have… long time ago. I stopped blogging due to changes in my personal situation, which led to a priority shift. Being a father to two beautiful daughters sure takes a lot of time! But I missed the possibility to share some notes, thoughts, ideas and the like.

Automatic scan for known vulnerabilities in dependencies

When using third-party components (be it open source or not), we all know it’s a good practice to keep your frameworks and libraries up to date. This is also one of the spearhead in the OWASP Top 10 (2013 edition): A9 - Using Components with Known Vulnerabilities. To help you assess your projects status with regard to this, OWASP.org developed the tool Dependency Check. This tool is primarily intended code bases in Java, .NET, Ruby, Node.js, and Python. Integration with various build tools is also provided for.

Tweaking nginx for serving static content

For a recent project, we decided to use the nginx webserver as our primary web server. It is easy, relatively light-weight, and it seemed to suit our needs quite well. The project had a lot of static content - HTML, JavaScript, CSS and image files. Of course, we wanted to achieve a high performance with as many concurrent requests being served as possible. This is what we did. Setup First of all, it is worth to mention the setup.

Quickly count your code base

Often, the size of a code base is measured in terms of “source lines of code” (SLoC). If you’re interested in the size of your code base - or your client is - this metric provides a way to express that size. Of course, comments and the like are not considered to be code, so how to determine this metric? Using grep is tempting, but it quickly results in a very complex and hard-to-understand approach.