So, I had a very specific situation to ignore an error from an agent. Turns that this seems even easier and quicker to ignore an specific error using an OEM Metric… How? Using agent parameter adrAlertLogErrorCodeExcludeRegex.
How to do it? Well, [AGENT_INST]/sysman/config/emd.properties, add a line with this parameters and the Regex to ignore the desired error or message.
To ignore all ORA-700, por example, it can be done by:
Now to ignore, for example, ORA 700 [kskvmstatact: excessive swapping observed]
After this, a restart on agent is required.
This is also well documented as per MOS EM 12c, 13c: How to Disable or Suppress OEM Alerts for Alert Log Error ORA-700 (Doc ID 2406779.1)
Hope it helps!