On Tue, Feb 4, 2014 at 4:10 PM, Robert Wille <rwille@fold3.com> wrote:
I would almost think that this is caused by high load on the server, but I’ve never seen CPU utilization go above about two of my eight available cores. If high load triggers this problem, then that is very disconcerting. That means that a CPU spike could permanently cripple a node. Okay, not permanently, but until a manual flush occurs.

While it is unlikely to be related to CPU (i/o much more likely...), the JVM is certainly capable of finding itself in a low-heap situation which :

1) performs very poorly
2) does not crash
3) and cannot be recovered from

This usually requires a restart of the JVM. This mental model should be an expectation for any application running in the JVM.