Mapping Logical Systems 
Mapping logical systems allows you to use functions from different back-end systems in a Java Web Dynpro application that is integrated in the SAP NetWeaver Portal. Multiple back-end support for the Adaptive RFC model is the prerequisite provided by Web Dynpro technology.
Naming Conventions
The target system name must contain the original system name as a prefix and can be extended by a maximum of three characters. Furthermore, the URL parameter can only contain the suffix of the new system name and thus only the added maximum of three characters. The old system name cannot be used as a parameter.
Procedure
You configure the logical target system name in the Web Dynpro Content Administrator.
With the configuration of the Portal page, you pass the following URL parameters with the Web Dynpro application. These parameters are then taken into account when the application is started.
sap-wd-arfc-useSys=<DEFAULT_SYSTEM>:<SUFFIX_OF_MAPPED_SYSTEM> |
If several systems are to be mapped, the parameter sap-wd-arfc-useSys can be repeated any number of times within a URL entry. One parameter entry is made for each logical system.
The mapping is only valid for the running application instance.
The URL parameters for the Portal page are maintained as described in the Administration Guide of the SAP Enterprise Portal.
Example
You have developed a Web Dynpro self-service application ESSApp that uses the functions of a back-end system XYZ. The logical system names of the application are WD_MODELDATA_DEST and WD_RFC_METADATA_DEST.
The application is now also to have access to the functions of a second system ABC. The target names for the logical systems should be called WD_MODELDATA_DESTABC and WD_RFC_METADATA_DESTABC.
The application URL with these parameters now looks like this:
http://<hostname>:<port>/webdynpro/dispatcher/local/ESSProject/ESSApp?
|
The original URL notation sap.wdarfc.useSys, which is now no longer permitted, is accepted by the browser due to the downward compatibility of the current URL parameter.
Additional Information
When using multiple back-end systems via mapping, there are guidelines to increase the security of logical systems.