JOnAS 4.x


Demo files

  1. Generating a cluster configuration with the newjc tool : newjc.htm
  2. Quick tour of the cluster management features in the jonasAdmin console : clusterManagement.htm
  3. SampleCluster2 example for demonstrating the load-balancing : sampleCluster2.htm

Cluster architecture and configuration

All the demonstrations are based on a common cluster architecture described in the following figure :


  • single machine : the cluster configuration is collocated on a single machine
  • master node : management node enabling to administrate the cluster from a centralized console
  • db node : HSQL database node embedded into a JOnAS
  • cd : cluster daemon, bootstrap of a JOnAS node for the remote control
  • apache/mod_jk : HTTP server with the plugin enabling the load balancing of the HTTP flow
  • node1-2 : JOnAS nodes of the web level
  • node3-4 : JOnAS nodes of the ejb level
  • myCluster : logical cluster gathering the 4 JOnAS nodes, described in domain.xml
  • sampleCluster2Domain : domain name of the configuration
  • java client : fat client
  • CMI : RMI protocol for the cluster mode ensuring the JNDI replication and the EJB clustering
  • HA : SFSB replication
  • HTTP session : HTTP session replication

The sampleCluster2 example provided with JOnAS is used for illustrating the load balancing both at the web level and the ejb level. For each request, the application prints the crossed node names. The application relies on the following components :


  • sessionServlet : main servlet starting a new session and entry point for sending a request across the cluster. The servlet gets information about the web container
  • releaseSessionServlet : servlet used for releasing a session
  • checkSessionServlet : servlet used for checking the validity of a session
  • myEjb1 : stateless EJB getting information about the ejb container
  • myStateful : stateful EJB used for storing the requests history
  • ClientSFSBFO : fat java client used for illustrating the SFSB high availability
  • ClientLBRemote : fat java client used for illustrating the load balancing of the SLSB at the business method level

Thread Management Framework (TMF)

Demo files

TMF stands for Thread Management Framework.

This tool provides a mechanism for controlling and monitoring the threads creation within a JVM.

TMF is delivered with JOnAS 4.8 as an experimental feature. 

  1. Overview : TMF.htm