Summary
Too many process running for ExeMgr , this is slowing the system down consuming resources. Until columnstore is restarted these threads dont close.

Expected
Once a query completes, threads of ExeMgr that are spawned are properly closed.

Actual
New threads keep appearing never closing. These appear to spawn when queries are waiting to be executed.

Reproduction

bash explodeExemgr.bash

bash explodeExemgr.bash 300

then watch the following

strace -p $(pidof ExeMgr)

cat /proc/$(pidof PrimProc)/status | grep -i threads

cat /proc/$(pidof ExeMgr)/status | grep -i threads

ps -efT | grep ExeMgr | wc -l