Missed your question about the tomcat cluster. Yes, you should use a separate variable for that :(. With JBoss 5, this will be easier as by default all services will share a single JGroups channel. And there will be a startup switch (a la -u, -b, etc.) for setting the mcast_port for the shared channel. BTW, the reason for setting the mcast_port to a different value for different groups is discussed here: http://wiki.jboss.org/wiki/Wiki.jsp?page=PromiscuousTraffic . If not for this issue, using different values for -u would be sufficient. Also, if you aren't using 4.0.4 or later, edit the ClusterName attribute in tc5-cluster-service.xml for it's value is "Tomcat-${jboss.partition.name:DefaultPartition}". That will cause the value you pass to -g to be part of the name, further helping to isolate the 50 clusters. In 4.0.4 and later the default value for ClusterName uses that syntax. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4020617#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...