A Java geek

Java makes it possible to compile Java code at runtime…​ any Java code. The entry-point to the compilation is the ToolProvider class. From its Javadoc: Provides methods for locating tool providers, for example, providers of compilers. This class complements the functionality of ServiceLoader. This class is available in Java since version 1.6 - released 10 years ago, but seems to have been largely ignored. The code Here’s a snippet that allows that: public class Ev

In this post, I’d like to explore a sample data set using Kibana. This requires some data to start with: let’s index some tweets. It’s quite straightforward to achieve that by following explanations found in my good friend David’s blog post and wait for some time to fill the index with data. Basic metric Let’s start with something basic, the number of tweets indexed so far. In Kibana, go to Visualize  Metric, then choose the twitter index. For the Aggreg

Though Kotlin and Spring Boot play well together, there are some friction areas between the two. IMHO, chief among them is the fact that Kotlin classes and methods are final by default. The Kotlin docs cite the following reason: The open annotation on a class is the opposite of Java’s final: it allows others to inherit from this class.

Some weeks ago, I wrote a post detailing how to send JMX metrics from a Spring Boot app to Elasticsearch by developing another Spring Boot app. Getting to create such an app is not always the right idea but developers are makers - software makers, and developing new apps is quite alluring to them. However, in the overall scheme of things, this means time is not only spent in development, but also for maintenance during the entire lifetime of the app. Before going the development path, one shoul

Nowadays, most companies use one or another Agile methodology for their software development projects. That makes people involved in software development projects at least aware of agile principles - whether they truly try to follow agile practices or just pay lip service to them for a variety of reasons remains debatable. To avoid any association with tainted practices, I’d rather use the name 'Exploratory Development'. As with software development, exploration has a vague feeling of the f

Last week, I wrote about how one could start developing one’s Logstash plugin coming from a Java developer background. However, with the acquisition of Packetbeat, Logstash now has help from Beats to push data to Elasticsearch. Beats are developed in Go, another challenge for traditional Java developers. This week, I tried porting my Logstash Reddit plugin to a dedicated Beat. This post documents my findings (spoiler: I found it much easier than with Ruby). Setting up the environment On

I recently became interested in Logstash, and after playing with it for a while, I decided to create my own custom plugin for learning purpose. I chose to pull data from Reddit because a) I use it often and b) there’s no existing plugin that offers that.

This week’s post aims to describe how to send JMX metrics taken from the JVM to an Elasticsearch instance. Business app requirements The business app(s) has some minor requirements. The easiest use-case is to start from a Spring Boot application. In order for metrics to be available, just add the Actuator dependency to it: <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-actuator</artifactId> </dependency&

Given the trend around microservices, it has become mandatory to be able to follow a transaction across multiple microservices. Spring Cloud Sleuth is such a distributed tracing system fully integrated into the Spring Boot ecosystem. By adding the spring-cloud-starter-sleuth into a project’s POM, it instantly becomes Sleuth-enabled and every standard log call automatically adds additional data, such as spanId and traceId to the usual data. 2016-11-25 19:05:53.221 INFO [demo-app,b4d33156

As a Java developer, when you are first shown how to run the JVM in debug mode, attach to it and then set a breakpoint, you really feel like you’ve reached a step on your developer journey. Well, at least I did. Now the world is going full microservice and knowing that trick means less and less in it everyday. This week, I was playing with Logstash to see how I could send all of an application exceptions to an Elasticsearch instance, so I could display them on a Kibana dashboard for analy