Jps on Micha Kops' Tech Notes

Snippet: Java Mission Control (JMC) and Flight Recorder (JFR)

Wed, 11 Oct 2017 00:00:00 +0200

The Java Mission Control and the Java Flight Recorder allow us to capture run-time information from our Java applications without much overhead and aggregate profiling information.

I have written down the commands that I’m using the most when profiling a Java application with this tool chain in the following article.

Figure 1. Java Mission Control - Report

Running Java Mission Control (JMC)

We may start the JMC user interface shown above using the jmc command that is shipped with Oracle’s JRockit or Java (since Java 7 update 40).

Finding Memory Leaks using Eclipse and the MemoryAnalyzer Plugin

Wed, 02 Nov 2011 00:00:00 +0100

The MemoryAnalyzer Plugin for Eclipse allows us to quickly analyze heap dumps from a virtual machine and search for memory leaks. In the following tutorial we’re going to create and run a small application that is going to cause an OutOfMemoryException during its runtime.

In addition, we’re forcing the virtual machine to save a heap dump and finally analyzing this data using Eclipse and the MemoryAnalyzer plugin.

Prerequisites

Java Snippets

Mon, 01 Mar 2010 00:00:00 +0100

Remote Debug a Pod’s Java Process

Simple steps for remote debugging a Java process running on a k8 pod:

Edit deployment and add the following parameters to the Java start line: -agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=127.0.0.1:5005

Also add the following port mapping at the section container → ports in the deployment:
```
- containerPort: 5005
  protocol: TCP
```
Safe, wait for the new pods and then add a port forward for port 5005 for this pod:
```
kubectl port-forward podname 5005
```