If your servers are having problems communicating, start with http://wiki.jboss.org/wiki/Wiki.jsp?page=TestingJBoss. If those all work OK, next step is to turn on TRACE level logging for category org.jboss.ha and see if it reveals anything. The suggestion to increase the buffer size was wrongheaded; based on faulty memory. The key thing is the buffers need to be bigger than the 512KB chunks that the FarmService breaks files into for transmission. The buffers in the original config were already large enough. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4031775#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...