Are you using user/container managed transactions or are you relying on ModeShape to start & commit each transaction within session.save() ? If the former, this bug: [MODE-2495] Transactional changes not propagated correctly when using user transactions shared by multiple threads - JBo… may be relevant.
In any case, once you have a test case I can use to reproduce the issue locally, pls open a new JIRA. Thanks.
I'm using container managed transactions. I did see the above issue but in my case I'm using a single thread per transaction whereas I believe they are using multiple threads spanning a single transaction, although the issues may well be related.
I'm focusing on getting a test going today. Given the timing nature involved it may not be 100% repeatable, especially on faster hardware.