Suddenly, in one day all my jobs are not running without showing any error.even though I have no trust of Oracle Scheduler but I wouldn't like to jump unless I solve the issue.
At the same time I was having an issue with EM so I needed to recreate it again.
SQL> show parameter job
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
job_queue_processes integer 0
What Make it 0?? I think from EM recreation
just by altering this value everything returned back as normal.
SQL> alter system set job_queue_processes=1000;
System altered.
SQL> show parameter job
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
job_queue_processes integer 1000
Reference: