Two years ago, I published a Maven archetype for Hadoop that turned out to be quite popular, judging from the comments I received and the access logs on my server. Today I've updated it to use the latest version of Hadoop and to build on Maven 3 without warnings.

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JUnit 4 introduced a fancy DSL based on the Hamcrest framework for expressing assertions. JUnit ships with the most important matchers and you can always add Hamcrest to your classpath if you need more. Sometimes no existing matcher fits your needs and you have to roll your own. Since it's …

Occasionally, it's useful to run multiple JBoss instances on one machine. Like with any network server, this is difficult because only one application can bind to a port at any given time. You have to assign different sets of ports to each instance. JBoss consists of quite a few network …

Java's Servlet spec allows web applications to delegate authentication and authorization to the servlet container, a mechanism known as container-based security. A lot of people use it for in-house applications or web services because it's simple and containers like Tomcat already provide several authentication backends to choose from. There's one …

I think every Java application in production should enable JMX access. Without JMX, there's little chance to debug JVM-level problems, especially those related to out of memory errors. Even if your application doesn't export its own MBeans for monitoring, you can still take advantage of those that come out of …

It's quite common to deploy web applications from a nightly continuous integration job to a testing server. In my case, I want to deploy a Java web application to a remote Tomcat server from a Maven build. Enter Cargo, a collection of tools for controlling Java EE containers like Tomcat …

Previously when you had …

In my last article I showed how to build a Hadoop job that contains all its dependencies. To make things even easier, I created a Maven archetype that turns project setup into a simple 30 second process.

To generate a new project run the following command (on one line):

mvn …

Non-trivial Hadoop jobs usually have dependencies that go beyond those provided by the Hadoop runtime environment. That means, if your job needs additional libraries you have to make sure they are on Hadoop's classpath as soon as the job is executed. This article shows how you can build a self-contained …