When you run slave versions of ActiveMQ broker in a journal filesystem Master/Slave setup, you better watch out for file handle leaks. This problem was reported a long time ago (in 4.1 release) and it still has not been fixed in the latest 5.0 release of AMQ. So the only way to avoid this is to manually apply the patch and rebuild activeio-core library and activemq itself.
ActiveMQ issue tracker is a good place to check the state of open bugs.
Interesting interview with the ActiveMQ lead.
