We are getting the following error messages in event_demon log:
[03.12.2017 07:14:02] CAUAJM_E_18402 ORA-00001: unique constraint (AEDBADMIN.XPKUJO_PROC_EVENT) violated
[03.12.2017 07:14:02] ORA-06512: at "AEDBADMIN.UJO_BATCH_MOVE_EVENT", line 33
[03.12.2017 07:14:02] ORA-06512: at line 1
[03.12.2017 07:14:02] CAUAJM_I_18403 Processing OCI function ODEFIN(34)
[03.12.2017 07:14:02] CAUAJM_E_18400 An error has occurred while interfacing with ORACLE.
[03.12.2017 07:14:02] CAUAJM_E_18401 Function <doExecute> invoked from <nextRow> failed <966>
[03.12.2017 07:14:07] CAUAJM_E_18416 Event Server: <RAR1O> Failed Query: <BEGIN :RetVal := ujo_batch_move_event (:I_time, :B_count); END; <<1512281647>>>
Jobs are running fine.
You may find a lot of entries with "gc freelist" in the oracle logs. This is known bug 18628388.
This bug is only relevant when using Real Application Clusters (RAC).
GCS cache lock is not closed fast enough and "gc freelist" wait appears on heavy load system.
If you see "gc freelist" wait occupies major part of database wait events, you might see this problem.
Patch can be obtained thru MyOracleSupport.