Re: FileCacheLoader, I think it would be strange if some corruption happened to the same session on 2 different systems. The limitiations of the FCL are: * Due to the way the FileCacheLoader represents a tree structure on disk (directories and files) traversal is inefficient for deep trees. * Usage on shared filesystems like NFS, Windows shares, etc. should be avoided as these do not implement proper file locking and can cause data corruption. * Usage with an isolation level of NONE can cause corrupt writes as multiple threads attempt to write to the same file. * File systems are inherently not transactional, so when attempting to use your cache in a transactional context, failures when writing to the file (which happens during the commit phase) cannot be recovered. I assume you aren't using a shared filesystem for the session store. The isolation level NONE caveat doesn't apply. The problem with not being able to recover if a write failure occurs in a tx is semi-relevant, but I'd expect then you'd have seen some errors in the logs when the session was persisted. Re: the pattern of failures, how close is the timing of the logging between the servers? You're using buddy replication, right? That would explain only 2 servers being involved -- the server handling the session and its buddy. View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4261919#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...