Ticket representing question/bug from drools user group: https://groups.google.com/forum/#!topic/drools-usage/Gy3uhkh6J78

Hello Drools users,

I found an anomaly in Drools 6.5. I insert an Event, which triggers a rule with a timer after some time. For backup reasons I marshal the session inbetween to back it up and on unmarshal it later. However, after unmarshalling it, the scheduled activations are sometimes scheduled as if just inserted (e.g. 1min scheduling, with marshal/unmarshal after 25s results in the activation firing after 85 (25+60) seconds instead of actual 60s. I know this worked with Drools 5.6 consistently, but now it sometimes works, sometimes not, which is indeterministic.

I created a test reproducing this behaviour, which has changing output whenever you execute it. What the example does: It create a scheduled activation, which should trigger after 20s. After 10s the session is marshalled, destroyed and unmarshalled into a new session. After another 10s it should finally trigger. (10s + 10s -> the 20s scheduled).