That could very well be the issue. When there's a topology change, basically one thread loops through all the services that are monitoring the cluster notifying them of the change. Eventually those calls reach your singletons. If each of those singletons then takes a long time starting, the whole process will be slow. If the startup of a singleton is going to take a long time and it can be done asynchronously, it's definitely better to do it that way. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3971345#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...