I want to discuss about this OMS error coming from the agent’s heartbeat status. The agent shows with an unreachable status but is actually up and running.
$: emctl status agent
Oracle Enterprise Manager Cloud Control 13c Release 2
Copyright (c) 1996, 2016 Oracle Corporation. All rights reserved.
Agent Version : 18.104.22.168.0
OMS Version : (unknown)
Last Reload : (none)
Last successful upload : (none)
Last attempted upload : (none)
Total Megabytes of XML files uploaded so far : 0
Number of XML files pending upload : 2,210
Size of XML files pending upload(MB) : 2.89
Available disk space on upload filesystem : 56.39%
Collection Status : Collections enabled
Heartbeat Status : OMS responded illegally [ERROR- Failed to Update Target Type Metadata]
Last attempted heartbeat to OMS : 2017-01-24 21:09:21
Last successful heartbeat to OMS : (none)
Next scheduled heartbeat to OMS : 2017-01-24 21:09:51
Agent is Running and Ready
In this case the agent is not able to upload the metadata because is different in the OMS.
This is mainly due to a patch in the agent side that is missing in the OMS. By mistake I applied the latest bundle patch to the agent before applying it to the OMS.
Just another proof that any patches have to be installed to the OMS first then the agents.