After a server with WebLogic installed is restarted either normally or abnormally, there is a known issue where the managed WebLogic servers are unable to be started up using the Node Manager inside the WebLogic Administration Console. Errors produced are:
“For server MANAGED_SERVER_NAME, the Node Manager associated with machine MACHINE_NAME is not reachable.”
To solve this problem, please follow these steps below:
1. Make sure all managed WebLogic servers are shut down.
2. Shut down the AdminServer.
3. Stop the Node Manager. In Windows, this can be done by stopping the Windows service (if installed) or closing out of the Command Prompt window running startNodeManager.cmd.
4. In the file system, delete the following files for each managed server:
a. %DOMAIN_HOME%\servers\%MANAGED_SERVER_NAME%\data\nodemanager\%MANAGED_SERVER_NAME%.state
b. %DOMAIN_HOME%\servers\%MANAGED_SERVER_NAME%\data\nodemanager\%MANAGED_SERVER_NAME%.lck
c. %DOMAIN_HOME%\servers\%MANAGED_SERVER_NAME%\data\nodemanager\%MANAGED_SERVER_NAME%.pid
NOTE: If any of the above three files do not appear, that will be perfectly fine as that can happen sometimes.
5. Start up the Node Manager.
6. Start the Admin Server using either a startup script or WLST.
After applying the steps above, you should be able to start the managed servers from the Admin Console.
Source: Oracle Support note 1293552.1
