I don't think it's this as I believe our limits are high enough :
Memoy Soft Limit is set to : 30720M
Memory Hardd Limit is set to : 32768M
My guess is more something to do with xCache hitting the 1024MB limit any trying to empty all this memory at one time, taking a few seconds to do this and causing PHP to crash…
Maybe xCache isn't meant for large servers…
Off topic, but any idea when I post a new answer to litespeedtech.com's forums my answers are always truncated, I have to hit return to copy my answer then go and edit my answer ? This is a real pain !