Using JES XCF Services

The following provides some recommendations and considerations when you invoke the JES XCF services through standard JES exits or JES3 DSPs. But first, a word of caution:

Attention:

If you choose to use the macros in JES exits or JES3 DSPs, or independent of any JES exit or JES3 DSP, you can do so, although their use outside standard exits is not recommended. Defining exits and writing installation exit routines is intended to be accomplished by experienced system programmers; the reader is assumed to have knowledge of JES2, JES3, or both.

If you want to customize your JES system, IBM recommends that you use the JES XCF installation exits and standard JES exits and JES3 DSPs to accomplish the task. IBM does not recommend or support alteration to JES source code.

You can use exit IXZXIT03 for two separate purposes:

To maintain a separate attachment to the JES common coupling service.
You don't necessarily need to use IXZXIT03 for this purpose unless you determine that your installation requires a separate attachment to JES XCF that is independent of the JES-defined attachment. Refer to Determining If You Should Use the JES-Defined Attachment for a further discussion of your potential need. All JES common coupling services are available using the JES-defined attachment.
To provide storage for use by, and shared by, both exit IXZXIT01 and IXZXIT02 processing. (You only need to obtain this storage if you intend to alter JES message processing.)