it's starting to kill child processes and eventually stops/hangs.
#plesk version
Product version: 12.0.18 Update #45
Update date: 2015/05/08 03:13
Build date: 2015/01/26 15:00
Build target: CentOS 7
Revision: 334346
Architecture: 64-bit
Wrapper version: 1.2
#free -m
total used free shared buff/cache available
Mem: 3782 647 2281 45 854 2875
Swap: 2047 0 2047
#plesk version
Product version: 12.0.18 Update #45
Update date: 2015/05/08 03:13
Build date: 2015/01/26 15:00
Build target: CentOS 7
Revision: 334346
Architecture: 64-bit
Wrapper version: 1.2
#free -m
total used free shared buff/cache available
Mem: 3782 647 2281 45 854 2875
Swap: 2047 0 2047