The Coupling Facility from the Point of View of the Programmer

To a programmer, a coupling facility can be viewed as shared storage that is directly accessible to connections distributed throughout the sysplex. Connections using a coupling facility must reside on systems with a direct attachment to the coupling facility.

Sysplex services for data sharing allow you to:

Store and access data in the coupling facility.
Choose synchronous or asynchronous structure operations, with a variety of options for handling operation completion.
Tailor structures and services for your specific needs by customizing your structure and by coding exits to respond to events and make decisions.
Use multiple structures, either for different purposes within the application or to implement a complex function. For instance, an application could use a lock structure to implement a serialization mechanism for use with a cache structure
Specify whether a structure is to be deallocated if there are no active users connected to it or whether the structure is to remain allocated until it is explicitly deallocated.
Relocate a structure elsewhere in the same coupling facility or in a different one.
Change the size of a structure and/or reapportion the use of structure storage based on application growth or workload variations.
Obtain diagnostic information about a coupling facility and its structures.