"bstansberry(a)jboss.com" wrote : If I understand you correctly, that implies that internally the cache stores everything as a byte[] or MarshalledValue or some such. This includes the elements of Fqns, as these can also be typed. At some level, but it does not have to be the core. Having the namespace be typed and potentially scoped I'm sure complicates interaction of what might be shared/common aspects. If the cache is used in pure in memory mode, there should be no need to serialize the data. If you through in a cache loader, then you have another serialization path. It certainly needs the correct class loader, but its separate from the current jgroups message issue. Is there a common serialization abstraction for these two cases? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3989537#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...