The Node Manager is a WebLogic Server utility that enables you to start, shut down and restart the Administration Server and the Managed Server instances from a remote location. Although Node Manager is optional, it is highly recommended to use it for applications with high availability requirements.
A Node Manager process is not associated with a specific WebLogic domain but with a Machine. You can use the same Node Manager process to control server instances in any WebLogic Server domain, as long as the server instances reside on the same Machine as the Node Manager process.
The Node Manager must run on each computer that hosts WebLogic Server instances (whether Administration Server or Managed Server) that you want to control with Node Manager.
The Node Manager communicates with Administration Servers and Managed Servers using two-way SSL. The default WebLogic Server installation includes demonstration Identity and Trust keystores that allow you to use SSL out of the box. The keystores—DemoIdentity.jks and DemoTrust.jks—are installed in $MW_HOME\wlserver\server\libfolder.
Starting Weblogic Node Manager
Look up for the script named startNodeManager.sh / startNodeManager.cmd within the folder $MW_HOME\wlserver\server\bin
Before starting the Node Manager, you need to have the correct environment available so, at first, execute the script setWLSEnv which is located as well in the bin folder:
Next, start the Node Manager using the script:
Now verify that the Node Manager is actually running on the port selected in the Machine configuration:
<23-jul-2012 11.34.09> <INFO> <Plain socket listener started on port 5556>
23-jul-2012 11.34.09 weblogic.nodemanager.server.Listener run INFO: Plain socket listener started on port 5556
The startNodeManager script contains all the JVM options needed to customize the Node Manager process, which will be ultimately triggered by the weblogic.NodeManager class.
Common issues when starting the Node Manager
Since the Node Manager uses by default native libraries to optimize its work, some issues can raise if your environment is not configured properly. A very common issue is:
“weblogic.nodemanager.common.ConfigException: Native version is enabled but node manager native library could not be loaded”
You can fix this by making sure that the Library Path is set properly. There are some variables available like “LD_LIBRARY_PATH (UNIX only)” and “SHLIB_PATH” (For HP-UX operating system) to set the correct Library Path:
Example: (For Solaris/Linux)
Alternatively, you can create/update the file $MW_HOME/wlserver/common/nodemanager/nodemanager.properties (where nodemanager.properties is Node Manager’s properties file created at start-up) with the entry: