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How To Troubleshoot OEM 12c Cloud Control Auto-Discovery

I was recently involved with an upgrade project to go from to on an Exadata V2. We hit some snags during the upgrade specifically related to OEM 12c Cloud Control. We performed an out-of-place upgrade and OEM had some difficulty in dealing with this.

12c Cloud Control is supposed to run a daily check which looks for new targets on each server. When it finds something new, it places this in a queue to wait for admin approval. With a single click you can promote the newly discovered target into an OEM managed object.

  • You can manually trigger this process. Go to Setup -> Add Target -> Configure Auto-Discovery -> Multiple Target-Type Discovery: Configure/Wrench-Icon -> Run Discovery Now
  • You can view the queue and promote targets by navigating to Setup -> Add Target -> Auto Discovery Results

It looks like a very nice process – except that it’s not working at all on our system. The stuff currently in our queue hasn’t existed on the server for years, and the new stuff is not getting detected and added to the queue. I haven’t complete solved this yet, but I have learned a few things in the process of working on it.

Few Useful References

First off, a few useful references about auto discovery. OEM is very extensible and you can create your own target types and write your own auto-discovery scripts.

Key takeaway: auto discovery is driven by a script which is sitting on the server. Generally written in Perl. This script does not change anything when it runs – it only generates output: a list of all targets that it currently sees. OEM sorts out which are new. This means that it’s safe to manually run the auto-discovery script on the server and see if it’s working as expected.

Additional note: some scripts will also write debug information (info/debug/trace) to emagent_perl.trc in the Management Agent log directory.

Manually Running Auto-Discovery

Took me a few tries to get all the library references right, but you can now just copy and past the commands below to run the Oracle Home auto-discovery yourself. Should only be minor tweaks to run other auto-discovery scripts.

[oracle@server:~]$ cd $AGENT_HOME
[oracle@server:/u01/app/oracle/product/12.1]$ export LD_LIBRARY_PATH=$AGENT_HOME/core/
[oracle@server:/u01/app/oracle/product/12.1]$ core/ -Icore/ -Icore/ plugins/oracle.sysman.oh.discovery.plugin_12.

Update Feb 18: You can get all four nodes at once by copying the following dcli command:

dcli -l oracle -g ~/dbs_group LD_LIBRARY_PATH=$AGENT_HOME/core/ $AGENT_HOME/core/ -I $AGENT_HOME/core/ -I $AGENT_HOME/core/ $AGENT_HOME/plugins/oracle.sysman.oh.discovery.plugin_12.

Manually Adding Targets

After you’ve run that script, you can manually add the targets using the exact outputs from the auto-discovery script. In most situations you probably don’t need to do this, but it’s neat that there’s a one-to-one correlation between the manual add parameters and the script output.

Manually Adding Oracle Home

Manually Adding Oracle Home

I’m curious – has anyone else ever had to troubleshoot auto-discovery? Care to share about your experience? Any additional tips you can add?