Variables come in many varieties. They are used to control settings and properties relating to the server environment. The three main types of variables that you should understand are environment variables, WebSphere variables, and custom properties.
Environment variables. Environment variables, also called native environment variables, are not specific to WebSphere Application Server and are defined by other elements, such as UNIX, Language Environment (LE), or third-party vendors, among others. Some of the UNIX-specific native variables are LIBPATH and STEPLIB. These variables tend to be operating system-specific.
Environment variables can also be specified as an application server custom property. To specify an environment variable as a custom property, in the administrative console, click Server > Application server > servername. Then, under Server Infrastructure, click Java and Process Management > Process Definition > Custom Properties.
WebSphere variables are name and value pairs that are used to provide settings for any of the string data type attributes contained in one of the XML formatted configuration files that reside in the product repository. After a variable is defined, the value specified for the variable replaces the variable name whenever the variable name is encountered during configuration processing.
WebSphere variables can be used to configure:
- WebSphere Application Server path names, such as JAVA_HOME, and APP_INSTALL_ROOT
- Certain cell-wide customization values
To create or modify a WebSphere variable, in the administrative console click Environment > WebSphere Variables.
A variable can apply to a cell, a cluster, a node, or a server.
How the variable is set determines its scope. If the variable is set:
- At the server level, it applies to the entire server.
- At the node level, it applies to all servers in the node, unless you set the same variable at the server level. In that case, for that server, the setting that is specified at the server level overrides the setting that is specified at the node level.
- At the cell level, it applies to all nodes in that cell, unless you set the same variable at the node or server level.
- If you set the same variable at the server level, for that server, the setting that is specified at the server level overrides the setting that is specified at the cell level.
- If you set the same variable at the node level, for all servers in that node, the setting that is specified at the node level overrides the setting that is specified at the cell level.
Custom properties are property settings meant for a specific functional component. Any configuration element can have a custom property. Common configuration elements are cell, node, server, Web container, and transaction service. A limited number of supported custom properties are available and these properties can be set in the administrative console using the custom properties link that is associated with the functional component.
For example, to set Web container custom properties, click Servers > Application Servers > servername > Web Container Settings > Web container > Custom Properties
Custom properties set from the Web container custom properties page apply to all transports that are associated with that Web container; custom properties set from one of the Web container transport chain or HTTP transport custom properties pages apply only to that specific HTTP transport chain or HTTP transport. If the same property is set on both the Web container page and either a transport chain or HTTP transport page, the settings on the transport chain or HTTP transport page override the settings that are defined for the Web container for that specific transport.
Configuring WebSphere variables Related reference
Session management custom properties Web container custom properties
HTTP transport custom properties
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IBM is a trademark of the IBM Corporation in the United States, other countries, or both.