We tried switching the 2 statements, but we still get the same behavior. I'll put together some instructions on using the test and send them to you. Thanks again for taking the time to look at this!

On Tue, Apr 29, 2014 at 2:20 PM, <wolfgang@exist-db.org> wrote:
I really expected the util:exclusive-lock to fix the issue. Well, one other thing I just noticed when re-reading your report: in the line

(update replace $node/text() with $node/text() + 1,$node/text() + 1)

the update replace is executed first, so when you return $node/text() + 1, the counter has already been incremented and you are actually returning the previous value + 2? What happens if you switch the two statements?

If the problem persists, could you provide some instructions on how to use the test from jmeter or send us the corresponding config?