Using OMS DEBUG mode to troubleshoot OEM 12c problems

This time, I want to show you how to troubleshoot OEM problems by enabling DEBUG mode in the OMS. The virtual machine (VM) running my sandbox installation of OEM 12c 12.1.0.4 crashed during the night. After restarting the VM and all the OEM components, I wasn’t able to login using the SYSMAN account. The error from the console was not very explicit, just, “Authentication failed. If problem persists, contact your system administrator.”

In order to get more details about the error, I decided to enable DEBUG mode for the OMS and reproduce the error. This is what I did to enable DEBUG mode.

$ cd /u01/app/oracle/oms/oms/bin
$ ./emctl set property -name log4j.rootCategory -value "DEBUG, emlogAppender, emtrcAppender" -module logging
Oracle Enterprise Manager Cloud Control 12c Release 4
Copyright (c) 1996, 2014 Oracle Corporation.  All rights reserved.
SYSMAN password:
Property log4j.rootCategory has been set to value DEBUG, emlogAppender, emtrcAppender for all Management Servers
OMS restart is not required to reflect the new property value

After enabling DEBUG mode, I reproduced the error several times using the console. I also wrote down the approximate time of the error, just to easy the search in the log file. Searching in the emoms.trc file located under /em/EMGC_OMS1/sysman/log/, found an ORA-14400 error. The MOS note 1493151.1, explains how to fix the issue by adding a new audit partition.


$ cd /u01/app/oracle/gc_inst/em/EMGC_OMS1/sysman/log/
$ view emoms.trc
java.sql.SQLException: ORA-14400: inserted partition key does not map to any partition


The final step is to disable the DEBUG mode for your OMS, otherwise the log files can grow real big and the performance could be affected.

$ ./emctl set property -name log4j.rootCategory -module LOGGING -value "WARN, emlogAppender, emtrcAppender"
Oracle Enterprise Manager Cloud Control 12c Release 4
Copyright (c) 1996, 2014 Oracle Corporation.  All rights reserved.
SYSMAN password:
Property log4j.rootCategory has been set to value WARN, emlogAppender, emtrcAppender for all Management Servers
OMS restart is not required to reflect the new property value

I hope this information is useful to you next time you are troubleshooting an OEM 12c issue.