Node Manager associated with machine is not reachable

The Node Manager associated with machine is not reachable!

 

Error: Following error is received while starting the managed servers from WLS console:

For server <server_name>, the Node Manager associated with machine <machine_name> is not reachable.

 

 

 

 

 

Cause: One of the reason you get this is error, is the incorrect properties set for nodemanager in “nodemanager.properties” file.

 

Detail RCA:

The Node Manager details can be configured from following location in WLS console:

Home > Environment > Machines > “You Machine” > Configuration > Node Manager > Type:

 

This is where most of the times people forget to change the value of listener type as “Plain” and use default type “ssl”, without configuring SSL.

In such cases when you start the nodemanager, it comes up without any complaints, and still you end up with domain that is unable to access nodemanager.

 

The devil lies in the details!

If you observe the nodemanager startup log, you’ll notice the below line, which indicates that listener has started in secure mode and not plain mode.

“<INFO> <Secure Socket listener started on port 5556, host /127.0.0.1>”

 

 

While some do remember to configure the node manager type as Plain in WLS console, they still face this issue, as one also needs to ensure that the “SecureListener” parameter is set to false in “DOMAIN_HOME/ nodemanager/nodemanager.properties”.

 

So the final Solution is:

1.       Remember to change the Weblogic listener type parameter to

“Plain” in “Home > Environment > Machines > “You Machine” > Configuration > Node Manager > Type:”

2.       Ensure that “SecureListener” parameter is set to false in “DOMAIN_HOME/ nodemanager/nodemanager.properties”.