EM12c Oracle Database Plug-In 12.1.0.7 update now shows 10g listener as down when it's not

Question

EM 12.1.0.4 with Oracle Database Plug-in 12.1.0.7
Monitored database and listener:  10.2.0.4
Our EM12c monitors 12.1,11.2 and 10.2 databases and listeners.  All monitored targets are up and running.
I updated Oracle Database Plug-in from 12.1.0.6 to 12.1.0.7 and now the only 10g listener that I have shows as down.
The listener on the server is up and running.
The monitoring configuration is right.
I removed this target and re-added it, but it came back as down.
It's a little disconcerting to have a listener show as down since it's a production box, but nothing I do corrects the problem.
Any insights or suggestions are appreciated.
Sherrie

Answer 1

Hi Sherrie,
In most cases we have this issue due to monitoring configuration , I know you mentioned that you have checked on it but still I would recommend to just re-confirm on below steps
1. Go to
    EM Console -> Targets -> Listener -> Listener Home page -> Target Setup -> Monitoring Configuration
2. Get the details
      Listener Name
      Listener.ora Directory
      Machine Name
      Oracle Home
      TCP Port Numbe
3. Go to the server where this listener is running
   Check to see if the listener is up
       ps -ef | grep tns
4. Next run
       $ORACLE_HOME/bin/lsnrctl status
   From this outpuy verify details in (1)
      Listener Name   <======= Alias
      Listener.ora Directory <=== Listener Parameter File ie the directory
      Machine Name  <======= HOST=
      Oracle Home<========== This is where tnslsnr is started from
      TCP Port Number <======  PORT=
5. Makes sure that all the details matches in (4) and (2)
If above is fine then I would recommend to go through the troubleshooting steps as per below doc , they are valid for listener status down too and should give a further insight on the root cause of the issue
Troubleshooting the 'Pending' status for a Listener Target in Enterprise Manager 12c Cloud Control (Doc ID 1546576.1)
Regards,
Rahul