Agent Unable to Communicate with OMS EM12c

My phone started going crazy with alerts from EM12c, apparently all of my agents had lost communication with OMS.  I immediately started checking all of the logs on OMS, not finding anything of interest I decided to try an upload from one of the host:

./emctl upload agent

WARN – Ping communication error
o.s.emSDK.agent.comm.exception.ConnectException [Failure connecting to https://HOST.domain.com:4889/empbs/upload , err host.domain.com]

./emctl pingOMS

Can’t find host host.domain.com

Interesting, but makes sense after all the only agent able to communicate to the OMS actually resides on the same host.

ping host.domain.com

Same results

After an email exchange with the Linux administration some changes had occurred in DNS that needed to be reverted.  Once that had been completed the ping worked and all agents showed as up.

 

 

Restart EM12c Agent

At times I’m not able to restart the EM12c agent from the console.   Fortunately command line works like a champ.

cd to the home directory of you agent bin directory

cd /u01/app/oracle/agent/agent_inst/bin

./emctl start agent

Oracle Enterprise Manager 12c Cloud Control 12.1.0.1.0
Copyright (c) 1996, 2011 Oracle Corporation.  All rights reserved.
Starting agent ........................................ started.

A ps -ef|grep emagent will provide the details of the process once started.

You can then reload the page within the console the agent should now display as up. If you don’t get an all clear with the green up arrow.

1. Click on the target of interest from the main target list page
2. Click on the word Agent with the downward triangle.
3. Displayed is a list of actions that can be performed on the agent. Select Resynchronization.
4. The Agent Resynchronization page will be displayed. Leave the check box by the unblock agent on successful completion checked.
5. Move over to the far right hand side of the page and click Continue.

Once this task is completed the agent should display as up.