[WebSphere Learning Record] 3. Variables

Variable

Variables have many variants. They are used to control settings and properties related to the server environment. Three major variable types should be known: environment variables, WebSphere variables, and custom variables.

Environment Variable. Environment variable (also knownLocal Environment Variable) Is not specific to WebSphere Application Server and is defined by other elements (such as UNIX, language environment (LE), or third-party vendors. Some UNIX-specific local variables are libpath and steplib. These variables tend to be specific to the operating system.

You can also specify environment variables as custom properties of the application server. To specify environment variables as custom properties, clickServer> Application Server>SERVER_NAME. Then, under "server infrastructure", clickJava and process management> process definition> Custom Attributes.

WebSphere Variables

WebSphere variables are name/value pairs used to set any string data type attributes contained in the XML format configuration file (residing in the product repository. After a variable is defined, the variable name is replaced by the value specified for the variable whenever the variable name is encountered during configuration processing.

WebSphere variables can be used to configure the following items:

• WebSphere Application Server Path, for example, java_home and app_install_root
• Custom values in certain unit ranges

To create or modify WebSphere variables, click environment> WebSphere variables in the console.

Variables can be applied to nodes or servers.

The way variables are set determines their scope. If the variable is set:

• At the server level, it is applied to the entire server.
• At the node level, it is applied to all servers in the node, unless you have set the same variable at the server level. When the same variable is set at the server level, the settings specified at the server level will overwrite the settings specified at the node level.

Custom Attributes

Custom Attributes are attribute settings for specific functional components. Any configuration element can have a custom attribute. Common configuration elements are units, nodes, servers, Web containers, and transaction services. A few supported custom attributes are provided, and you can set these attributes by using the custom attribute link associated with the feature component in the management console.

For example, to set custom properties for Web containers, clickServer> Application Server>SERVER_NAME> Web Container Settings> Web Container> Custom Attributes

The custom property set from the custom properties page of the Web Container applies to all the transmissions associated with the Web container; A custom property set from the Web container transport link or HTTP transport custom property page is only applicable to this specific HTTP transport link or HTTP transport. If the same attribute is set on the Web Container page and the transmission link or HTTP transmission page, the settings on the transmission link or HTTP transmission page will overwrite the settings defined for the specific transfer Web container.

From:
Http://publib.boulder.ibm.com/infocenter/wasinfo/v6r0/topic/com.ibm.websphere.base.doc/info/aes/ AE /welcvariables.html