Enterprise Manager does much of its heavy lifting inside the repository database through jobs in the jobs queue.

Symptoms of broken jobs process include delayed target posting, clusters that appear in a pending state after you’ve done all the configuration, and other general slowness.

To resolve the issue in OEM 12c

1. Connect to the repository database as the SYSMAN user and execute the following
alter system set job_queue_processes=10;
exec emd_maintenance.remove_em_dbms_jobs;
exec emd_maintenance.submit_em_dbms_jobs;
2. Log into the OEM console
Click on Repository Database Target in Cloud Control
Click on Administration/Oracle Scheduler/Home
Then click on “Oracle Scheduler; it will return, “Scheduler Jobs”
Check that the scheduled jobs are running at their correct schedules. eg. check ‘EM_JOBS_MONITOR’ which should run every 5 minutes. Check that the “scheduled date” is five minutes after the last run date”, and check that it’s in status “SCHEDULED”.
These jobs have different scheduled running intervals, so certain jobs only run once a day, and one only runs once a week. It’s possible to view the scheduled interval by clicking on “view job definition”.