Monitoring the build

The most popular way of starting a Maven build is by using the mvn clean install command. This will build all the Maven modules under your project and install the artifacts to your local repository. For a simple project, the entire build process will take less than a minute. However, for a large project, to create an online build with a clean repository could even take more than 3 hours: this is not an exaggeration. If you look at the WSO2 Carbon complete code base, the complete build process takes more than four hours to run with all the test cases. During a long-running build process, it is extremely important that we monitor the build properly.

Note

WSO2 Carbon is a framework that is written on top of OSGi to build servers. All WSO2 products, which are 100 percent open source and released under Apache 2.0 license, are built on top of WSO2 Carbon. WSO2 Carbon code base is available at https://svn.wso2.org/repos/wso2/carbon/.

The following screenshot shows an overview of the JVisualVM tool running a Maven build:

Note

JVisualVM is a Java virtual machine monitoring, troubleshooting, and profiling tool. To learn more about it, refer http://docs.oracle.com/javase/6/docs/technotes/tools/share/jvisualvm.html.

The JVisualVM tool that comes with the JDK distribution can be used to monitor a running Maven build. First, we need to start the Maven build and then start JVisualVM using the following command:

$ jvisualvm

This command will start the JVisualVM tool. Once the tool gets started, select org.codehaus.plexus.classworlds.launcher.Launcher from the Applications tab to monitor the running Maven build. You can gather many important statistics using JVisualVM, and based on that you can optimize your system resources for an optimal Maven build.

The following screenshot shows JVisualVM statistics of a running Maven build: