Hello again, I am still trying to create a minimal example to reproduce the problem.
If I am using only 1 NIO worker on server side it is easy to reproduce. So, I assume there must be at least two workers, that there is one that always could call the notifyAll method to wake up all the sleeping ones. Can you give me some hints, how you ensure, that there is always one worker free to notify the ones that call lock.wait? A perhaps more readable (because of the line breaks) version of the thread dump could be found here: https://gist.github.com/maggu2810/4c8df61e95938102726376a044ca9a9e Best regards, Markus
