If you can't find better solution, you can have different permutations of SessionIdAlphabet in each node. They are set in jbossweb-tomcat55.sar/META-INF/jboss-service.xml Looking at the SessionID generation code, having these characters (they must be 65, rememeber) permuted in each node will decrease the probabilities of having duplicated session ids... Hope it helps. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4030412#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...