EM 12c, EM 13c: emctl start / status agent Reports: Error: java.net.UnknownHostException (Doc ID 1589130.1)

Last updated on JUNE 15, 2021

Applies to:

Enterprise Manager Base Platform - Version 12.1.0.1.0 and later
Information in this document applies to any platform.

Symptoms

Use Case 1

$agent_inst/bin/emctl start agent

failes to start

Oracle Enterprise Manager Cloud Control 12c Release 2
Copyright (c) 1996, 2012 Oracle Corporation. All rights reserved.
Starting agent ..........Consult emctl.log and emagent.nohup in:

agent_inst/sysman/log/gcagent.log reportes the following error

2014-11-12 09:59:48,436 [124:FF086F13:Persistence(Agent - https://<host>:3872/emd/persistence/main/)] (https://<host>:3872/emd/persistence/main/)]) WARN - Agent persistence got unknown host
java.net.UnknownHostException: <host>
at java.net.InetAddress.getAllByName0(InetAddress.java:1156)
at java.net.InetAddress.getAllByName(InetAddress.java:1082)

Use Case 2

$agent_inst/bin/emctl status agent

reports the following java exception

The following exception occurred:
java.net.UnknownHostException: <host>.com
at java.net.Inet6AddressImpl.lookupAllHostAddr(Native Method)
at java.net.InetAddress$1.lookupAllHostAddr(InetAddress.java:848)
at java.net.InetAddress.getAddressFromNameService(InetAddress.java:1201)
at java.net.InetAddress.getAllByName0(InetAddress.java:1152)
at java.net.InetAddress.getAllByName(InetAddress.java:1082)
at java.net.InetAddress.getAllByName(InetAddress.java:1018)
at java.net.InetAddress.getByName(InetAddress.java:968)
at oracle.sysman.emd.targetIntg.agent.AgentTargetInstaller.getLocalHost(AgentTargetInstaller.java:5455)
at oracle.sysman.emd.targetIntg.agent.AgentTargetInstaller.printLocalHost(AgentTargetInstaller.java:5415)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at oracle.sysman.emd.targetIntg.Util$DefaultIntegrationMethod.execute(Util.java:617)
at oracle.sysman.emd.targetIntg.TargetInstaller.execute_(TargetInstaller.java:171)
at oracle.sysman.emd.targetIntg.TargetInstaller.execute(TargetInstaller.java:159)
at oracle.sysman.emSDK.conf.TargetInstaller.printLocalHost(TargetInstaller.java:2744)
at oracle.sysman.emSDK.conf.TargetInstaller.main(TargetInstaller.java:3895)
Although there was an exception it might be possible for the program to continue.
Oracle Enterprise Manager Cloud Control 12c Release 3
Copyright (c) 1996, 2013 Oracle Corporation. All rights reserved.
---------------------------------------------------------------
Agent Version : 12.1.0.3.0
OMS Version : 12.1.0.3.0
Protocol Version : 12.1.0.1.0
Agent Home : /u01/agenthome/agent_inst