Transparency to application

An application that uses function shipping need not know the location of the requested resources; it uses file control commands, temporary storage commands, and so on, as if all resources are owned by the system in which the application runs. Entries in the CICS® resource definition tables allow the system programmer to specify that the named resource is not on the local (or requesting) system but on a remote (or owning) system.

The definition of a remote resource can include both the name by which the resource is known in the remote system, and a different name by which it is known locally. When the resource is requested by its local name, CICS substitutes the remote name before sending the request. This facility is useful when resources exist with the same name on more than one system, but each contains data peculiar to the system on which it is located.

Application programs can use the SYSID option of various EXEC CICS commands to name remote systems explicitly. If this option is specified, the request is routed directly to the named system, and the resource definition tables on the local system are not used. Using SYSID in this way destroys the program’s independence of the resource’s location. The advantage is that any system, including the local system, can be named in the SYSID option. The decision whether to access a local resource or a remote one can be taken at execution time.

Related concepts
Introduction to function shipping
Remote resources that can be accessed
How function shipping works
Synchronization
Function shipping examples
Related reference
CICS product communication support
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