Overview of Node Manager Configuration
This section describes general Node Manager configuration that applies to the Java and script version of Node Manager. You should ensure than you have performed all of the items outlined in the following sections.
After you have you have performed general Node Manager configuration, you should perform the configuration procedures outlined in Configuring Java Node Manager or Configuring Script Node Manager depending on which version of Node Manager you are using.
Step 1: Configure Your Computer to Run Node Manager
Node Manager must run on each computer that hosts a WebLogic Server instance. Configure each computer as a machine resource in WebLogic Server, and assign each server instance that you will control with Node Manager to the machine upon which it runs.
Ideally, Node Manager should run as an operating system service or daemon, so that it is automatically restarted in the event of system failure or reboot. See Installing the Node Manager Windows Service in the Installation Guide.
Node Manager is ready-to-run after WebLogic Server installation if you run Node Manager and the Administration Server on the same machine, and use the demonstration SSL configuration. By default, the following behaviors are configured:
Controlling and Configuring Node Manager Using WLST
The WebLogic Scripting Tool (WLST) is a command-line scripting interface that system administrators and operators use to monitor and manage WebLogic Server instances and domains. You can start, stop, and restart server instances remotely or locally, using WLST as a Node Manager client. In addition, WLST can obtain server status and retrieve the contents of the server output log and Node Manager log. For more information on WLST commands, see WLST Command and Variable Reference in WebLogic Scritpting Tool.
Using nmConnect in a Production Environment
WLST can connect to a Node Manager that is running on any machine and start one or more WebLogic Server instances on the machine. A domain’s Administration Server does not need to be running for WLST and Node Manager to start a server instance using this technique.
However, by default, the nmConnect command cannot be used in a production environment. You must first perform the following procedures to use
nmConnect in a production environment. - Start the Administration Server.
- Using the Administration Console update the Node Manager credentials from the Advanced options under domain_name
Security
- Invoke WLST and connect to an Administration Server using the connect command. See Using the WebLogic Scripting Tool in WebLogic Scripting Tool.
- Run nmEnroll using the following syntax:
Running
nmEnroll() ensures that the correct Node Manager user and password token are supplied to each Managed Server. Once these are available for each Managed Server, you can use nmConnect() in a production environment. | Note: | You must run nmEnroll() on each machine that is running a Managed Server. Additionally, you should run nmEnroll() for each domain directory on each machine. |
Step 2: Specify Node Manager Username and Password
The
nm_password.properties file contains the Node Manager username and password. These are used to authenticate connection between a client (for example, the Administration Server) and Node Manager. | Note: | This username and password are only used to authenticate connections between Node Manager and clients. They are independent from the server admin ID and password. |
This file is created when you use nmEnroll() to copy the necessary configurations files from one machine to another when creating a domain. After
nm_password.properties is created, you can change the values for the Node Manager password and properties using the Administration Console. Changes are propagated to the nm_password.properties file and are picked up by Node Manager. | Note: | If you edit nm_password.properties manually, you must restart Node Manager in order for the changes to take effect. |
The
nm_password.properties file must exist on each physical machine that runs Node Manager. However, the Node Manager username and password do not have to be identical on every machine within your domain. Step 3: Configure a Machine to Use Node Manager
A WebLogic Server machine resource associates a particular machine with the server instances it hosts, and specifies the connection attributes for the Node Manager process on that system.
Configure a machine definition for each machine that runs a Node Manager process using the EnvironmentMachines<machine_name>Node Manager page in the Administration Console. Enter the DNS name or IP address upon which Node Manager listens in the Listen Address field.
Machines<machine_name>Node Manager page in the Administration Console. Enter the DNS name or IP address upon which Node Manager listens in the Listen Address field. Step 4: Configuring nodemanager.domains File
The
nodemanager.domains file specifies the domains that a Node Manager instance controls. Thus stand-alone clients do not need to specify the domain directory explicitly. This file must contain an entry specifying the domain directory for each domain the Node Manager instance controls, in this form:
When a user issues a command for a domain, Node Manager looks up the domain directory from
nodemanager.domains. This file 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
nodemanager.domains. If you created your domain with the Configuration Wizard, the
nodemanager.domains file was created automatically. If necessary, you can manually edit nodemanager.domains to add a domain. | Note: | If you use the backslash character (\) in nodemanager.domains, you must escape it as (\\). |
Step 5: Configuring Remote Startup Arguments
In the Administration Console, on the ServerConfigurationServer Start page for the Managed Server, specify the startup arguments that Node Manager will use to start a Managed Server. If you do not specify startup arguments for a Managed Server, Node Manager uses its own properties as defaults to start the Managed Server. For more information, see Reviewing nodemanager.properties. Although these defaults are sufficient to boot a Managed Server, to ensure a consistent and reliable boot process, configure startup arguments for each Managed Server instance.
ConfigurationServer Start page for the Managed Server, specify the startup arguments that Node Manager will use to start a Managed Server. If you do not specify startup arguments for a Managed Server, Node Manager uses its own properties as defaults to start the Managed Server. For more information, see Reviewing nodemanager.properties. Although these defaults are sufficient to boot a Managed Server, to ensure a consistent and reliable boot process, configure startup arguments for each Managed Server instance. If you will run Node Manager as a Windows Service, as described in Installing the Node Manager Windows Service in the Installation Guide, you must configure the following JVM property for each Managed Server that will be under Node Manager control:
If you do not set this option, Node Manager will not be able to restart a Managed Server after a system reboot, due to this sequence of events:
- A reboot causes a running Managed Server to be killed before the Node Manager and Administration Server operating system services are shut down.
- During the interval between the Managed Server being killed, and the Node Manager service being shut down, Node Manager continues to monitor the Managed Server, detects that it was killed, and attempts to restart it.
- The operating system does not allow restart of the Managed Server because the machine is shutting down.
- Node Manager marks the Managed Server as failed, and it will not start this server when the machine comes up again.
Starting a Managed Server with the
-Xrs or -Xnohup option avoids this sequence of events by preventing the immediate shutdown of the Managed Server during machine shutdown. Step 6: Setting Server Startup Properties
You can use Node Manager to set the startup properties for a server. These properties can be defined in
startup.properties or passed as an object using administrative utilities such as WLST. The methods of setting startup properties and their valid values are outlined in the sections below. startup.properties
Node Manager uses the
startup.properties file to determine the startup configuration when starting a server. This file is defined for each server instance and is located in: The contents of
startup.properties are derived from the Server MBean, or the Cluster MBean if the server is part of a cluster. For more information, see the MBean reference. Setting Startup Properties Using WLST
When using the WLST nmStart command, the server configuration can not be determined directly. Therefore, you must pass the server start properties as a WLST properties object to the
nmStart() command. Server Startup Properties
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Step 7: Define the Administration Server Address
Make sure that a listen address is defined for each Administration Server that will connect to the Node Manager process. If the listen address for an Administration Server is not defined, when Node Manager starts a Managed Server it will direct the Managed Server to contact localhost for its configuration information.
Step 8: Set the Node Manager Environment Variables
You can set these variables manually on the command line or you can create a start script that sets them automatically. The sample start scripts provided with WebLogic Server,
startNodeManager.cmd and startNodeManager.sh, set the required variables.
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