In alert log file ,
sculkget: failed to lock /databases/ora10g//dbs/lkORCL exclusive
sculkget: lock held by PID: 6159

ORCL is my database instance name.

ORA-09968: unable to lock file
Linux Error: 11: Resource temporarily unavailable
Additional information: 6159

Then it starts stopping CJQ,MMNL and MMON background processes.