#21 Halef instability

[David Suendermann-Oeft]

Every now and then, Halef ends up dysfunctional and needs to be restarted. This ticket is to track down the reason for this. Please list observations and examples for when you saw this happening. We need to be able to reproduce this issue to fix it. For example, there are definitely issues like this associated with concurrent calls hitting the same Halef instance as tracked by https://sourceforge.net/p/halef/tickets/3/ .