As Joshua Bloch says, "concurrency is hard." David Jordan,
The model.begin/model.commit/model.abort trio seems to work okay for all operations within a single JVM, although if you look at the code I included with my original question you'll a lot of decoration that may or may not be required. Where my problem happens is when multiple JVMs are reading and one is writing. Damian Steer, An explicit begin/end is what I have in my code (which you see in the original post in this thread). There is also (a possibly not needed) pair of notifyEvents bookending the transaction. Are you suggesting I must also set autocommit to false for that code to work over multiple JVMs, or is explicit use of begin/end enough? Dave L.
