I am running a cluster of 2 instancesof JBOSS 3.2.2 using tomcat on the same machine.
I changed the port #'s in all the configuration file to start the other instance.
The files I changed for the second instance are:
all/conf/jacorb.properties
all/conf/jboss-service.xml
all/deploy/cluster-service.xml
all/deploy/http-inovker.sar/META-INF/jboss-service.xml
all/deploy/jbossweb-tomcat41.sar/META-INF/jboss-service.xml
all/deploy/jms/oil2-service.xml
all/deploy/jms/oil-service.xml
all/deploy/jms/uil2-service.xml
all/deploy/snmp-adaptor/META-INF/jboss-service.xml

I changed all the port #'s by adding 1 in front of the existing port #'s. I am trying to test the
failover by stopping one instance. Session variables are getting replicated to other instance,
but I am asked to relogin again. I am using form based authentication and Apache2 with mod_jk2.
I can provide more information, if it is not enough. I am getting the following error when I stop the instance.
Please let me know what I am doing wrong.

11:03:24,227 INFO [EjbModule] Stopping jboss.j2ee:module=ClusteredHttpSessionEB
.jar,service=EjbModule
11:03:24,227 ERROR [EjbModule] unexpected exception stopping Container: jboss.j2
ee:jndiName=clustering/HTTPSession,service=EJB
java.lang.NullPointerException
at org.jboss.ejb.EjbModule.stopService(EjbModule.java:346)
at org.jboss.system.ServiceMBeanSupport.stop(ServiceMBeanSupport.java:24
0)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.
java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAcces
sorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:324)
at org.jboss.mx.capability.ReflectedMBeanDispatcher.invoke(ReflectedMBea
nDispatcher.java:284)
at org.jboss.mx.server.MBeanServerImpl.invoke(MBeanServerImpl.java:546)
at org.jboss.system.ServiceController$ServiceProxy.invoke(ServiceControl
ler.java:976)
at $Proxy14.stop(Unknown Source)
at org.jboss.system.ServiceController.stop(ServiceController.java:471)
at sun.reflect.GeneratedMethodAccessor122.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAcces
sorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:324)
at org.jboss.mx.capability.ReflectedMBeanDispatcher.invoke(ReflectedMBea
nDispatcher.java:284)
at org.jboss.mx.server.MBeanServerImpl.invoke(MBeanServerImpl.java:546)
at org.jboss.mx.util.MBeanProxyExt.invoke(MBeanProxyExt.java:177)
at $Proxy12.stop(Unknown Source)
at org.jboss.ejb.EJBDeployer.stop(EJBDeployer.java:567)
at org.jboss.deployment.MainDeployer.stop(MainDeployer.java:489)
at org.jboss.deployment.MainDeployer.stop(MainDeployer.java:504)
at org.jboss.deployment.MainDeployer.undeploy(MainDeployer.java:472)
at org.jboss.deployment.MainDeployer.shutdown(MainDeployer.java:359)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.
java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAcces
sorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:324)
at org.jboss.mx.capability.ReflectedMBeanDispatcher.invoke(ReflectedMBea
nDispatcher.java:284)
at org.jboss.mx.server.MBeanServerImpl.invoke(MBeanServerImpl.java:546)
at org.jboss.system.server.ServerImpl$ShutdownHook.shutdownDeployments(S
erverImpl.java:849)
at org.jboss.system.server.ServerImpl$ShutdownHook.shutdown(ServerImpl.j
ava:824)
at org.jboss.system.server.ServerImpl$ShutdownHook.run(ServerImpl.java:8
12)
11:03:24,247 INFO [EJBModule] destroy(), remove EJB-Module: jboss.management.lo
cal:J2EEApplication=jbossha-httpsession.sar,J2EEServer=Local,j2eeType=EJBModule,
name=ClusteredHttpSessionEB.jar