The mod-cluster module, developed by JBoss, has many advantages over mod-jk, such as dynamic addition and removal of cluster nodes and web applications, and dynamic load balancing between httpd and the different JBoss servers. First, we'll present the architecture of mod-cluster and its advantages over mod-jk. Then we'll show how to configure mod-cluster and JBoss. Finally, we'll demo a dynamic cluster, running in the cloud (EC2). The demo includes adding new JBoss servers to a running system (e.g. to cover load spikes), removing running instances, and adding and removing web applications. Attendees will walk away with an understanding of what mod-cluster is and how to use it. Presenter: Bela completed his PhD at the University of Zurich, Switzerland. After some time at IBM Research, he did a post-doc at Cornell. Then he worked on NMS/EMS for Fujitsu Network Communications in San Jose, California. In 2003, he joined JBoss to work full-time on open source. Bela manages the Clustering Team at JBoss and created and leads the JGroups project. Bela's interests include network protocols, performance, group communication, trail running, biking and beerathlon. When not hacking code he spends time with his family.