Jolokia

From time to time people come to me and say: “I really would love Jolokia if only it would be RESTful”. This post tells you why.

Now that some weeks has been passed we all had time to absorb the revised Java EE 8 proposal presented at Java One. As you know, some JSRs remained, some things were added and some stuff was dropped. Java EE Management API 2.0, supposed to be a modern successor of JSR 77, is one of the three JSRs to be dropped. What does this mean for the future of Java EE management and monitoring ?

This screencast gives a live demo of the forthcoming JMX notification support in Jolokia 2.0.

I hope you all had a good start into 2016 and have charged all your batteries during the time of stillness. Jolokia had a good start, too. During the holiday season I took the opportunity to continue to work on version 2.0 which now takes on form. If you have followed the history of Jolokia you know that work on 2.0 started early 2013 but advanced quite slowly for multiple reasons. Now its time to go out on a limb with announcing Jolokia 2.0 for 2016. A bit of pressure sometimes really helps ;-)

As you might know, Jmx4Perl is the mother of Jolokia. But what might be not so known is, that Jmx4Perl provides a set of nice CLI tools for accessing Jolokia agents. However, installing Jmx4Perl manually is cumbersome because of its many Perl and also native dependencies. However, if you are a Docker user there is now a super easy way to benefit from this gems.

The HTTP-JMX Bridge Jolokia allows easy access to JMX. It exposes all JMX information and operations via an REST-like interface and has tons of nifty features. Jmx4Perl on the other side is a client for Jolokia, which beside Perl access modules also provides quite some nice CLI tools for accessing and installing Jolokia. This post explains how install these tools on OS X.

A health check is a useful technique for determining the overall operational state of a system in a consolidated form. It provides some kind of internal monitoring which collects metrics, evaluates them against some thresholds and provides a unified result. Health checks are now coming to Jolokia. This post explains the strategy to include health checks into Jolokia without blowing up the agents to much.

While on the way of transforming the Jolokia integration test suite from a tedious, manual, half-a-day procedure to a full automated process I ran into and felt in love with Docker. As a byproduct a java-jolokia docker repository emerged, which can be easily used as a Java base image for enabling a Jolokia JVM agent during startup for any Java application.

Jolokia has configurable CORS support so that it plays nicely together with the Browser world when it comes to cross origin requests. However, Jolokia’s CORS support is not without gotchas. This post explains how Jolokias CORS supports works, what are the issues and how I plan to solve them.