I've configured the packet delivery timeout and timeout for service guardian and going to put them on the server. (Not quite sure whether not specifying the timeouts is the problem.)
But there are still some parts unclear to me:
This is happening to me just once a week and exactly after weekends in the early working hours. (Does it really have to do with the idle time of the server in the weekend? Why just once a week and exactly on the first working day? If the GC is really running slowly why is this happening at this time?)
And the last question: Does service guardian monitor only threads belonging to Coherence or also other threads for possible deadlocks?