Extracting a Heap Dump from a running OpenJ9 Java process in Kubernetes

Posted by Joep Weijers on November 26, 2020

At TOPdesk we run many Java services in our Service Architecture. We use the AdoptopenJDK OpenJ9 JRE as base image for our services running in Kubernetes. In this post we will find out how to get a Java Heap Dump from a Java application running on OpenJ9 JRE.

A Java Heap Dump is a snapshot of all the objects that are in memory in the JVM at a certain moment. Typically, a heap dump is created at the moment a Java application crashes because it runs out of memory. The heap dump can then show you what the application was doing in its dying moments, providing insight into potential memory leaks.

Rolling updates in Kubernetes

Posted by Martijn van Lambalgen on January 8, 2018

So, you want to do rolling updates of your services in Kubernetes to achieve zero-downtime? That’s what we wanted to reach too, and what we’re doing now (mostly). Our journey involved quite a bit of research, filling of gaps in our lacking knowledge, learning from a multitude of mistakes, and a fair bit of trial and error. To make your journey more efficient, here is what we learned.