Scalability and High Availability for the JBoss Application Server

JBoss Clustering is a major piece of the puzzle that makes JBoss Application Server a true enterprise-class application server. With it's fail-over, load-balancing and distributed deployment features, JBoss Clustering provides the means to develop large, scalable robust applications.


  • Full clustering support for both traditional J2EE applications and EJB 3.0 POJO applications
  • Automatic discovery. Nodes in cluster find each other with no additional configuration.
  • Cluster-wide replicated JNDI context
  • Failover and load-balancing for JNDI, RMI and all EJB types
  • Stateful Session Bean state replication
  • HTTP Session replication
  • High Availability JMS
  • Farming. Distributed deployment of JBoss components. Deploying on one node deploys on all nodes.

Clustering is key to application scalability

Clustering is a key feature in Java EE application servers. It allows you to add more server hardware to handle more requests, to make your application fail-safe, and to make more efficient use of the database server. Clustering is traditionally important for high traffic web applications. But today, as AJAX and SOA applications become more and more popular, smaller web applications also need to handle large amounts of incremental page updates (AJAX) and machine-to-machine traffic (SOA). Therefore, clustering is becoming more and more important. In JBoss AS, clustering is mostly transparent to applications. That means you simply need to change a few configurations, without changing the application's Java code, to make it run in a JBoss cluster.

Clustering support for lightweight POJO applications

JBoss AS was the first application server to support transparent clustering of EJB 3.0 POJOs. It allows you take advantage of the simple new POJO programming model without compromising the superior scalability typically found in traditional J2EE applications. The JBoss AS supports EJB 3.0 entity bean cache clustering, EJB 3.0 stateful session bean clustering, and HTTP clustering out of the box. Check out a guided tour through a live web application to learn how to configure clustering for EJB 3.0 web applications.

About the Project

User Community Our user forums are the main channel of communication between all community members. If you experience problems, have questions, or simply want to meet the community, visit the forums.
Developers There are many community developers contributing to JBoss Clustering. If you are not on this list and you are a contributor, or have been in the past, send an email to labs-admin at with a short bio, a picture, and a list of the projects to which you contributed, and we will happily add you to this list of rock star programmers.
Getting Involved If you wish to get involved as a developer in the JBoss Clustering project, please visit the JBoss Clustering design forum and get to know people. Joining the jboss-development and jbosscache-dev mail lists is also a good idea. Also, it is recommended you visit the JIRA pages to get a glimpse of the status or project tasks.
All of the developers on the JBoss Clustering project began as independent contributors to one JBoss project or another. JBoss core developers are guided by a meritocracy, and we hire talent wherever in the world it may be.
More information JBoss Clustering Official Documentation
Wiki Knowledge Base
Project Status JBoss Clustering uses the JIRA tracking and project management system to organize and prioritize tasks. JBoss Clustering issues can be found by searching for issues with 'Clustering' as their Component.
Acknowledgements JBoss Clustering was created by professional open source developers from around the world. JBoss Clustering is built on top of the JGroups distributed messaging technology. Check out the great work Bela Ban has done to allow for the quick development of JBoss Clustering. JBoss Clustering originally began in 2001 as a small prototype built on top of JGroups and coded by Sacha Labourey. Bill Burke joined Sacha and for the AS 3.0 release they together built the JBoss Clustering core that's still in use today. Under Ben Wang's leadership, use of JBoss Cache for state replication was introduced in AS 3.2.6. The project is now led and maintained by Brian Stansberry.
Professional Support Red Hat Inc. delivers the Professional Support, Consulting, and Training that you need whether you are testing a proof of concept, deploying a mission-critical application, or rolling out JBoss across your enterprise.