The rest of the story... We created an application that uses JBossCache to share objects between nodes in the cluster. We configured JBossCache to utilize JGroups UDP communication which from what I can tell is configured nearly identical to the farm deployer. We noticed that if we ran two instances of JBoss within the same OS/virtual hardware we had excellent communications performance but when we split to two OS/virtual hardware the performance was pitiful. So, why? We had been using CentOS on top of Xen virtual hardware so we tried switching out one of those variables and running CentOS on top of VMWare and voila, massive performance benefit. So, something in our Xen hardware setup or Xen itself was causing very poor performance of UDP communications. Our solution at this point is simply to use VMWare. At some point I will get a chance to test the farm deployer against our VMWare based clusters and I'll try to post some results here but I fully expect it to work well. View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4260809#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...