What is the CallBackStore
Besides the default NullCallbackStore, there is a truly persistent CallbackStore, which will persist callback messages to disk so they will not be lost. The description of the CallbackStore is as follows: Acts as a persistent list which writes Serializable objects to disk and will retrieve them in same order in which they were added (FIFO). Each file will be named according to the current time (using System.currentTimeMillis() with the file suffix specified (see Section Callback store configuration). When the object is read and returned by calling the getNext() method, the file on disk for that object will be deleted. If for some reason the store VM crashes, the objects will still be available upon next startup CallbackStore is also a service mbean, so can be run as a service within JBoss AS or stand alone.