9.11.8 Problem with create/deleting user


I update my wiki from 7.4.6 to latest 9.11.8 and faced with strange problem.

When I delete user (he is in a group with over 5000 entries) then java thread in RUNNABLE state above 2 hour (and i think process is endless). I try to manually add new user and faced with same problem (each thread take ~ 25 percent of cpu and large ammount of allocated bytes).

In 7.4.6 all works fast enough.

Example of threads dump in attached files.

add_user.txt (10.6 KB)
delete_user.txt (7.2 KB)

Does anyone know cause of this problem?