We're also seeing this error, not out of state transfer, just randomly once in awhile on a busy day. We've noticed that setting eventQueueSize=400000 (for example) doesnt help, we still get the error at 200000. We've tried adjusting down the minTimeToLiveSeconds now, from one day, to one hour.
I dont think the problem is related to state transfer, its after i do the state transfer i look to empty the region, this i assume triggers eviction event(s) that get placed on the queue to get evicted.
I then get the above message(s) but what is worrying is that after things have cooled down i till have data items still in the cache for that region. It should be empty which leads me to believe that if the queue is full then the eviction event is discarded.
By the way the removeRegion does nothing for me, region is still there in its entirety. Is there any way of removing a region with many nodes in one go without causing a flood of events that overflows the queue??
Havent had the time to look at this since but its on my todo list.