This chapter includes the following topics:
Script-based Node Manager is a shell script,
wlscontrol.sh, located in
wlscontrol.sh file must exist on each machine that hosts server instances that you want to control with Node Manager. This script can be customized to meet site-specific requirements.
You must have an SSH client executable on each machine where Node Manager or a Node Manager client runs. This script must also be in the path of the user ID running it. Typically, an SSH client is a standard part of a UNIX or Linux installation.
Step 1: Create User Accounts
Before running Node Manager, create a dedicated UNIX user account for performing Node Manager functions. Add this user to all machines that host the script-based Node Manager and to all machines that host a Node Manager client, including the Administration Server.
On UNIX platforms, Oracle does not recommend running Node Manager as the root user. However, to achieve Post-Bind GID, you must start Node Manager as the root user. Post-Bind GID enables a server running on your machine to bind to a UNIX group ID (GID) after it finishes all privileged startup actions.
On each host machine, as the root user, create two new operating system (OS) users: bea and ndmgr, both associated with a new group called bea.
Use bea for installing Oracle WebLogic Server only.
Use ndmgr to create a WebLogic domain and start the Administration Server and remote Managed Servers using Node Manager.
Both OS users should have the same OS group (bea) to ensure that the correct permissions are in place for ndmgr to run WebLogic scripts and executables.
> groupadd bea > useradd -g bea -m bea > passwd bea > useradd -g bea -m ndmgr > passwd ndmgr
Step 2: Configure Node Manager Security
The Node Manager SSH shell script relies on SSH user-based security to provide a secure trust relationship between users on different machines. You create a UNIX user account typically one per domain, for running Node Manager commands and scripts. A user logged in as this user can issue Node Manager commands without providing a user name and password.
You must also ensure that the Node Manager and Oracle WebLogic Server commands are
available in the path of the UNIX user ID used to run them. Change the environment
file of the user to contain the path to
Configure SSH trust between the ndmgr user on each machine that will run an Oracle WebLogic Server instance and the same ndmgr user on the same machine, plus the corresponding ndmgr user on every other machine.
In other words, any ndmgr user on one machine must be able to establish an SSH session without being prompted for security credentials, with a ndmgr user of the same name on the same or a different machine. This is necessary because any Managed Server can become the cluster master for migratable servers and issue commands to start other remote Managed Servers in the cluster using SSH. For Managed Server migration to work, the ndmgr user needs only to be able to run the
wlscontrol.sh script using SSH. See Configuring Security for WebLogic Server Scripts.
For example, to configure one instance of a user to trust another instance of a user for SSH version2:
- From a terminal logged in as ndmgr
> ssh-keygen -t dsa
- When prompted, accept the default locations and press Enter for passphrase so that no passphrase is specified.
- Copy the ndmgr user's public key to the ndmgr user's home on the same
machine and all other
> scp .ssh/id_dsa.pub email@example.com:./
- Establish an SSH session with the target machine as the ndmgr user and set up
trust for the remote ndmgr
> ssh -l ndmgr 192.168.1.101 (you should be prompted for password) > mkdir .ssh > chmod 700 .ssh > touch .ssh/authorized_keys > chmod 700 .ssh/authorized_keys > cat id_dsa.pub >> .ssh/authorized_keys > rm id_dsa.pub > exit
- Test that you can establish an SSH session with the ndmgr user on the remote
machine without requiring a password.
> ssh -l ndmgr 192.168.1.101
- Repeat this process for all combinations of machines.
Alternatively, you can achieve the same result by generating a key value pair on each machine, concatenating all of the public keys into an
authorized_keys file, and copying (
scp) that file to all machines. Try establishing SSH sessions between all combinations of machines to ensure that the
~/.ssh/known_hosts files are correctly configured. See Generating and Distributing Key Value Pairs.
Step 3: Install Oracle WebLogic Server
Install an Oracle WebLogic Server instance in the base directory,
/wlserver, on all the machines
that will run Oracle WebLogic Server, where ORACLE_HOME represents the
directory you specify as the Oracle Home when you install Oracle WebLogic Server, for
> java -jar wls_jrf_generic.jar
See Starting the Installation Program in Installing and Configuring Oracle WebLogic Server and Coherence.
Step 4: Create a WebLogic Domain
Create a WebLogic domain using the Configuration Wizard on the machine which hosts the Administration Server only.
Subsequently, when you start the Administration Server, it will use the configuration in the
config subdirectory of this domain directory to determine the settings for the Administration Server and the domain.
It is likely that most Managed Server instances will be run remotely with respect to the Administration Server. Therefore, these Managed Servers will not have direct access to the domain configuration directory of the Administration Server. Instead, they will run from a skeleton domain directory in their respective machine's ndmgr home directory and will obtain their configuration over the network on startup from the remotely running Administration Server.
As the ndmgr user, create the WebLogic domain.
- Run the Configuration
- Create a new WebLogic domain based on the default Oracle WebLogic Server template.
- For the Administration Server, specify a fixed IP address (for example,
- In Customize Environment and Service Settings, select Yes.
- In Configure Managed Servers, add two Managed Servers,
For the Managed Servers, specify floating IP addresses (for example,
- In Configure Clusters, add a cluster,
CLUST, and then assign
Do not specify any Machines or UNIX Machines; you will do this manually in a subsequent step.
- Name the domain '
clustdomain' and save it to
Step 5: Configure nodemanager.domains File
nodemanager.domains file specifies the domains that a Node Manager instance controls. The standalone clients do not need to specify the domain directory explicitly. The file
nodemanager.domains provides additional security by restricting Node Manager client access to the domains listed in this file. The client can only execute commands for the domains listed in
This file must contain an entry specifying the domain directory for each domain a Node Manager instance controls, in this form:
When a user issues a command for a domain, Node Manager looks up the domain directory from
For the script-based Node Manager, this file's default location is
WL_HOME is the location in which you installed Oracle
WebLogic Server, for example,
If you are using the script-based implementation of Node Manager, you must create or copy into
nodemanager.domains file that specifies the domains that you want a Node Manager instance to control. Alternatively, you can register WebLogic domains with the script-based Node Manager using the WLST command,
nmEnroll. See Configuring nodemanager.domains File.
Step 6: Start the Administration Server
Aside from the standard method of starting the Administration Server by using the provided
startWebLogic scripts, use the script-based implementation of Node Manager to monitor the Administration Server to ensure high availability. Run the
wlscontrol.sh Node Manager script to start the Administration Server locally.
If using a production domain, create
boot.properties for the Administration Server for successful server startup. As the ndmgr user, start the Administration Server using the
wlscontrol.sh Node Manager script.
> ORACLE_HOME/wlserver/common/bin/wlscontrol.sh -d clustdomain -r
ORACLE_HOME/clustdomain -c -f startWebLogic.sh -s AdminServer START
For verbose logging to standard out, add the
-v parameter to the command.
Once the Administration Server has been successfully started, and the
boot.properties file has been created, you can start the Administration Server remotely. Stop the Administration Server using the
stopWebLogic.sh Node Manager script. Then, start the Administration Server remotely using SSH.
> ssh -l ndmgr -o PasswordAuthentication=no 192.168.1.100
ORACLE_HOME/wlserver/common/bin/wlscontrol.sh -d clustdomain -r /home/ndmgr/clustdomain -c -f startWebLogic.sh -s AdminServer START
Step 7: Configure Node Manager on the Managed Servers
Each machine that will host a Managed Server will have a skeleton domain created and configured.
From a local terminal, create a new empty directory (
clustdomain) in the home directory for the ndmgr user for each of the Managed Server host machines and also a back-up machine. For example:
> mkdir clustdomain
For each of the Managed Server host machines and the back-up machine, as the ndmgr user, use WLST to enroll the user's home directory as being the base directory for remotely run servers and for Node Manager.
> ORACLE_HOME/wlserver/common/bin/wlst.sh > connect('weblogic','weblogic','t3://192.168.1.100:7001') > nmEnroll('/home/ndmgr/clustdomain','/home/ndmgr') > exit()
Be sure to run
nmEnrollon each remote machine. This command creates a property file,
/home/ndmgr/nodemanager.domains, which maps domain names to home directories, and creates the required domain configuration and security information so that Managed Servers can communicate with the Administration Server.
Note:In previous releases,
nmEnrollwould download the domain encryption key (
SerializedSystemIni.datfile) from the Administration Server. However, now, if it does not already exist, you must manually copy the file from the Administration Server domain directory or an existing server in the domain before running the
nmEnrollcommand. The file location should be
nodemanager.domainsfile removes the need to specify the domain home directory (with
-r) when starting
wlscontrol.sh. However, since you changed the Node Manager home directory, you must specify
-n /home/ndmgr. The default Node Manager home directory is
ORACLE_HOME/wlserver/common/nodemanager; you might not want to use this directory as it is in the product installation directory and owned by another user.
By default, you can start a Node Manager from any directory. A warning will be issued if no
nodemanager.domainsfile is found. You must create or copy into
nodemanager.domainsfile that specifies the domains that you want a Node Manager instance to control or register WebLogic domains using the WLST command,
Step 8: Test Node Manager Setup and Configuration by Starting Managed Servers
Start the Managed Servers to test the Node Manager setup and configuration.
- Copy the scripts from the Administration Server's domain
bindirectory to the corresponding domain
bindirectory on each Node Manager machine (for example,
/home/ndmgr/bin). For example:
> scp firstname.lastname@example.org:"~/clustdomain/bin/*" email@example.com:~/clustdomain/bin
- For each Node Manager machine (including the back-up machine), edit the shell
scripts in the
bindirectory to reflect the proper path for the local domain home, and the remote Administration Server's IP address.
- Edit the
DOMAIN_HOMEvariables in the
setDomainEnv.shscript to correctly reflect this remote domain home directory:
- Similarly, edit the
- Edit the
t3://192.168.1.100:7001) variables in
- Edit the
- For each of the Managed Server host machines (including the back-up machine), as the
ndmgr user, create a
server/securitysubdirectory in the domain directory.For example, for the Managed Server
> mkdir -p ~/clustdomain/servers/MS1/security
Note:For the back-up machine, create a server directory for every migratable Managed Server (for example, both
- Create a new
boot.propertiesfile with the appropriate user name and password variables specified in each Managed Server's
securitydirectory (for example,
Note:When a Managed Server is first started using the script-based Node Manager, the values in this file will be encrypted.
- For each of the Managed Server machines, as the ndmgr user, start the Managed
Server locally from a terminal using the
wlscontrol.shNode Manager script.For example, to start the Managed Server,
> ORACLE_HOME/wlserver/common/bin/wlscontrol.sh -d clustdomain -n /home/ndmgr -c -f startManagedWebLogic.sh -s MS1 START
For verbose logging to standard out, add the
-vparameter to the command.
- Once successfully started, stop the Managed Servers and then, as the ndmgr
user, attempt to start the Managed Servers remotely using SSH.
For example to start
> ssh -l ndmgr -o PasswordAuthentication=no -p 22 192.168.1.101 ORACLE_HOME/wlserver/common/bin/wlscontrol.sh -d clustdomain -n /home/ndmgr -c -f startManagedWebLogic.sh -s MS1 START
- Once successfully started, stop the Managed Servers again and then repeat the
process by trying to start each Managed Server (
MS1) on the back-up machine instead. Again, stop this server once it successfully starts.
Step 9: Configure UNIX Machines
For more information about configuring UID or GID, see Unix Machine Configuration in the Oracle WebLogic Server Administration Console Online Help.
Table 4-1 UNIX Machine Settings
Node Manager Type
Node Manager Listen Address
Node Manager Listen Port
Node Manager Home
Node Manager Shell Command
ssh -l ndmgr -o PasswordAuthentication=no -p %P %H
ORACLE_HOME/wlserver/common/bin/wlscontrol.sh -d %D
-n /home/ndmgr -c -f startManagedWebLogic.sh -s %S %C
Node Manager Debug Enabled
Step 10: Assign Servers to Machines
After all of the UNIX Machines are created, use the WebLogic Server Administration Console to set the Machine property for each server, to ensure each server is associated with its corresponding UNIX Machine.
See Assign server instances to machines in the Oracle WebLogic Server Administration Console Online Help.
Step 11: Start Managed Servers
Use the WebLogic Server Administration Console to start the Managed Servers.
See Start Managed Servers from the Administration Console in the Oracle WebLogic Server Administration Console Online Help.
Check the server logs in the
/logs directory of each Managed Server to ensure that the server has started with no errors.
Configuring Script-Based Node Manager Security
To configure the script-based Node Manager security, perform the steps to override the default SSH port, configure the security for Oracle WebLogic Server scripts, configure remote server start security, and generate and distribute key value pairs.
This section includes the following topics:
Overriding the Default SSH Port
The default SSH port used by Node Manager is 22. You can override that setting in the following ways:
Port=parameter in the
~/.ssh/configfile to set the default port for an individual user.
Port=parameter in the
/etc/ssh_configfile to set the default port across the entire system.
Start the Administration Server using the following system property:
-Dweblogic.nodemanager.ShellCommand="ssh -o PasswordAuthentication=no -p %P %H wlscontrol.sh -d %D -r %R -s %S %C"
After starting the server, you can edit the SSH port in the Administration Server's configuration file.
Configuring Security for Oracle WebLogic Server Scripts
To perform server migration and other tasks, the user ID executing scripts such as
wlscontrol.sh must have sufficient security permissions. This
includes being able to bring an IP address online or take an IP address offline using a
Server migration is performed by the cluster master when it detects that a server has failed. It then uses SSH to launch a script on the target machine to begin the migration. The script on the target machine runs as the same user ID running the server on the cluster master.
The commands required to perform server migration are
arping. Since these scripts require elevated OS privileges, it is
important to note that this can prevent a potential security hole. Using
sudo, you can configure SSH to allow only
arping to be run using elevated
The scripts are located in the
directory or the
directory. See Step 2: Configure Node Manager Security.
Configuring Remote Server Start Security for Script-Based Node Manager
A remote start user name and password is required to start a server instance with Node Manager. These credentials are provided differently for Administration Servers and Managed Servers.
- Credentials for Managed Servers - When you invoke Node Manager to start a Managed Server, it obtains its remote start name and password from the Administration Server.
- Credentials for Administration Servers - When you invoke Node Manager to start an
Administration Server, the remote start user name can be provided on the command
line, or obtained from the Administration Server's
boot.propertiesfile. The Configuration Wizard initializes the
boot.propertiesfile and the
startup.propertiesfile for an Administration Server when you create the domain.
Any server instance started by Node Manager encrypts and saves the credentials with which it started in a server-specific
boot.properties file, for use in automatic restarts.
Generating and Distributing Key Value Pairs
The script-based Node Manager uses two types of key value pairs.
This section contains instructions for distributing key value pairs to the machines that will host a Node Manager client or server.
Shared Key Value Pair
This option distributes the same key value pair to all machines that will host a Node Manager client or server.
The simplest way to accomplish this is to set up your LAN to mount the Node Manager user home directory on each of the machines. This makes the key value pair available to the machines. Otherwise:
- Generate an RSA key value pair for the user with the
ssh-keygencommand provided with the SSH installation.
The default location for the private and public keys are
If these keys are stored in a different location, modify the
ShellCommandtemplate, adding an option to the
sshcommand to specify the location of the keys.
- Append the public key to the
~/.ssh/authorized_keysfile on the Node Manager machine.For example:
command="ORACLE_HOME/wlserver/common/nodemanager/nodemanager.sh" 1024 33 23...2323
In this command, you will substitute the public key that you generated, as stored in
id_rsa.pub, for the string shown in the example as:
1024 33 23...2323
commandensures that a user that establishes a session with the machine using the public key can run only the command specified—
nodemanager.sh. This ensures that the user can perform only Node Manager functions, and thus prevents unauthorized access to data, system utilities, or other resources on the machine.
- Manually distribute the key value pair to each machine that will host a Node Manager server instance or client.
- Execute the following command on the client machine to check that the Node Manager
client can access Node
$ ssh montgomery wlscontrol.sh VERSIONThis response indicates that the client accessed Node Manager successfully:
NodeManager version 12.1
Individual Key Value Pairs
On each machine that will host a Node Manager client: